This question is very similar to others on this forum, and I think almost everything in the question is answered there.

Does something exist separate from the physical body?

I don't think you will find the answer to that question in cognitive science, but rather in philosophy.  Taken from one of the answers:

  Your thought experiment hinges on the debate of materialism (the mind
  is a physical thing) versus dualism (the mind is a different kind of
  thing than other physical things). Most cognitive scientists believe
  that materialism is the correct view.

It is unclear whether or not science will ever definitively settle this question, but it may place some constraints on the role (if any) of non-physical entities.  As I mentioned in my reply:

  The large body of research that was spurred on by Libet's experiment
  has significantly changed our understanding of the role of "thought"
  or "will" or "volition" in the causal chain, such that they now appear
  to be a side-effect rather than cause of physical action.

Why would electrodes show that the impulse to move the hand came earlier than I was aware of it?

I think you are missing a 3rd option: Much of what happens in the brain is outside of our awareness.  This is called the unconscious mind.  The brain is a very complicated system, so exact causes for behaviours are still elusive, but the implication behind the Libet experiment is that the decision to move is made unconsciously - still inside the brain, but outside awareness.

EDIT (re updated question):

I'm not sure what you mean by "Subconscious seems like a hypothetical chaos that we ascribe all phenomena that we are unable to explain scientifically"...  Non-scientific terms such as "soul" or "mind" or "will" certainly fall under that category, as they don't add any information, and there are no tools available to study them, thus we know nothing about them.  The "unconscious mind" on the other hand, refers to physical, measurable processes in the brain, just ones outside our conscious awareness.  Cognitive scientists learn about unconscious processes through cognitive research, fMRI scans, and other tools of neuroscience for example.  Thus we have a great deal of knowledge about how the unconscious mind works.

What causes the unconscious mind to make decisions?

Again, this question comes down to the choice between materialism and dualism - the choice is yours to make.

Consider a simpler question: Say a computer makes a beeping sound a few seconds after someone presses a key - what caused it to do that?  (1) The computer needs a speaker with which to make the sound (hardware); (2) the computer needs a program that uses the speaker (software); and (3) it needs a user to press a key to run the program (input).

Now consider a much more complex machine: Say a human lifts their arm a few seconds after someone says "atten-hut!" - what caused them to do that?  (1) The human needs an arm to lift (biology); (2) the human needs to know when to salute (learning); and (3) they need someone to call them to attention (stimulus).  Like any machine, all actions are a result of its internal mechanisms, current state, and external environment.

But what if the computer makes a beeping sound with no one around to press a key?  Maybe at some point in the past someone ran a program that makes beeping sounds randomly every once in a while.  Or maybe it did it of its own "free will"?  What do you think?

And what if a human lifts their arm with no one around to salute?  Maybe at some point in their past, the person learned to salute for fun when they are bored and alone.  Or maybe it was their "free will"?  What do you think?


Is there evidence that listening to music can aid/hinder concentration or performance?

It basically depends on how the particular musical performance is perceived by the listener. Cognitive process of listening seems to be comprise several layers, which follows a bottom-up direction.

First step is to decode relevant signal(s), among a complex package of sound. This is where the irrelevant noise is eliminated. Can music be eliminated in this level? Highly unlikely, but still possible. I do not know of a particular experiment but when the music is being played in a far destination, or with a low volume, or if the participant is highly concentrated to the task; then it may be eliminated in this step. But the key point in this step is that the term "noise" refers to aperiodic background sounds. Therefore, my first impression is that music, being periodical, must decrease the task performance. Cutler and Clifton (1999)
gives an overview on the entire listening process. Second step is the grouping of different sound sources. There is also modelling studies that aims to explain this phenomenon (Bregman, 1990). Steps in listening continues further, but those steps are beyond the scope of this question.

But there are other studies also. Ylias and Heaven (2003) showed that the background noise negatively effects reading comprehension. So far so good. Cassidy and MacDonald (2007) showed that task performance on silence is greater than in low arousal music, and that is greater than noise, and that is even greater than high arousal music conditions. This is interesting, because it now introduces the affective state of the listener into the equation, which makes it a lot more difficult to handle. Another result is that the effect of the noise here is comparable to the effect of background music. But we have to note that the details of the noise in this experiment is not given in detail, only commented as "the everyday noise". It would be more conclusive if we just know whether it is the background sound of a television (periodic) or a traffic noise (aperiodic).

Combining these references, I cannot easily conclude that music is taken as a "noise". It seems that music reduces the task performance, by negatively affecting a later step in the listening process.

Ending note: There are several semiformal-informal studies on the web also. They study directly the "work/office performance", therefore I must say that they lack a little bit of a controlled environment. In such environments we can even confidently say that music improves our performance in particular situations. But what we miss is that office environments comprise several unhandled parameters that makes it hard for scientific experimental setup (i.e. listening music may improve the performance if your office mates chit chat next to you).

Ending note 2: I was interested in this topic a time ago. So I welcome more recent references or comments.

Cutler, A., & Clifton, C. (1999). Comprehending spoken language: A blueprint of the listener. The neurocognition of language, 123-166.
Bregman, A. S. (1984, July). Auditory scene analysis. In Proceedings of the 7th International Conference on Pattern Recognition (pp. 168-175).
Ylias, G., & Heaven, P. C. (2003). The influence of distraction on reading comprehension: a Big Five analysis. Personality and individual differences, 34(6), 1069-1079.
Cassidy, G., & MacDonald, R. A. (2007). The effect of background music and background noise on the task performance of introverts and extraverts. Psychology of Music, 35(3), 517-537.


What is the difference between Machiavellianism and good negotiating/influence skills?

The term "Machiavellianism" can be used to refer to adherence to a set of strategies and guidelines for manipulation (eg, "personally deliver good news but have bad news delivered by others"), a moral philosophy (eg, "the means justifies the ends"), or a personality trait (also called "Machiavellian intelligence").  Since you've posted this question on a cognitive science forum, I will focus on the latter definition.

Machiavellianism is measured (as any personality trait), using a self-report scale.  This test, the Mach-IV, developed by Christie & Geis (1970), does not measure negotiation skills, but mostly focuses on social and moral attitudes and beliefs.  As such, it would not normally be equated with any particular skills.

Fehr, Samson, & Paulhus (1992) review 17 years of research on Machiavellianism, including its association with persuasion:

  Several studies have found that high Machs are particularly adept at
  persuading others in bargaining situations.

The review also mentions some notable exceptions, including a study by Fry (1985), that showed that a simple visual barrier greatly reduces the influence of high Machs.  A more recent review by Jones & Paulhus (2009) also agrees:

  ... high Mach IV scores do predict who will and who will not engage in
  interpersonal manipulation.

So although the term refers to a set of self-reported attitudes about social relationships, and not a measure of any particular skills, it would be reasonable to say that Machiavellianism correlates with negotiation skills.

For completeness, I should mention that the strong correlation is not an accident.  In fact, as the review points out:

  ... the construct validity of Machiavellianism rests largely on the
  match between high Mach IV scores and actual pragmatic manipulation.

In other words, the test was written and adjusted to have this correlation, so it may be more accurate to say that Machiavellianism is validated by negotiation skills.


What important psychological results would not have been discovered without experiments on non-human animals?

I think this necessarily involves some speculation. It's very hard to tell whether certain important findings would have been discovered without studies in non-human animals. We should also keep the hindsight bias in mind, that is, the tendency to retroactively claim that we 'knew it all along'.

Another aspect to consider is that only experiments enable us to investigate the causality of a relationship that we might have already observed in a non-experimental context. For example, we might have already observed that people with depression also show signs of helplessness, but this usually isn't enough to assume a causal link between these two.

Finally, I do think there are a few findings that would have been almost impossible without research in non-human animals. For example, any knowledge that stems from the recording of individual neurons in the brain. It's currently infeasible to record data from individual neurons in humans (apart from a few patients that have medical devices implanted due to neurological disorders). So for example, our knowledge of dopamine neurons signaling reward prediction errors depended critically on research in non-human animals (Schultz et al., 1997, Science).


Why do some people refuse to wear their seat belt while being aware of the risks?

I think this is a rather difficult question to answer. Psychology Today sums up some interesting reasons why people totally aware of the risks involved in not wearing a seat belt (or in smoking tobacco products, alcohol abuse, dangerous driving...), still choose not to wear one (light up another cigarette etc.):

Justification of risky behavior may be re-enforced by unreliable anecdotes that "show" how safe it is. For example, a friend or relative never wears a seat belt and smokes every day. People can use this as 'evidence' that not buckling up or smoking are perfectly safe. The dreaded remark comes to mind that "My grampa smokes three packs a day and is in his nineties - now ciggies can't be that bad...".
In that same line, personal anecdotes can reinforce risky behavior. If it hasn't happened yet, it will never happen. When people have never worn a seat belt for the last five years, they may start assuming that it is safe, because nothing has happened. They believe in the pattern, rather than considering that that luck may well be running out. I never use a seat belt may be used as an argument to conclude that the absence of a bad outcome is evidence that one is somehow 'immune' to the danger involved.
The small statistical chances involved may be used consciously or subconsciously as excuse. When we think about taking another smoke, overeating, drinking yet another beer, or not wearing a seat-belt we often think There's very little chance that the next time it will kill me. This is all too true. The next cigarette may not, and in fact very likely will not, kill you. But what if this is your continual belief for the next 350,000 cigarettes during your lifetime? It may not be that the next cigarette will kill you, but it may be true that holding onto this belief will kill you, eventually.

All of these risks involve a sort of "near-sightedness". We focus on the next one-not on the long string of behaviors. We tend to think that the "next time I go out driving without my seat-belt, there is a very low probability that I will get killed". This is true, but each time increases the probability.

The underlying problem is that our primitive brains battles itself over short-term rewards versus long-term goals. As a regular quitter of smoking (I've stopped so, so many times) I know this more than anyone. The short-term reward is more important than the long run. Impulsive choices or preferences for short-term rewards result from the emotion-related parts of the brain winning out over the abstract-reasoning parts. Psychological factors other than pure reasoning often drive people's decisions, for example the small nuisance of the seat belt or the dangers of long-term smoking loose over the improved comfort of driving without a seat belt and activating the dopamine release in our limbic system when smoking a ciggie.

Our evolutionary more ancient emotional limbic brain has a hard time imagining the future, even though our logical, evolutionary more recent neocortical brain (Fig. 1) clearly sees the future consequences of our current actions. Our emotional brain wants to max out that credit card, order dessert and smoke a cigarette. Our logical brain knows we should save for retirement, go for a jog and quit smoking. Quite apparently, the primitive emotional brain often tips the balance and defeats the newer evolved logical brain.

Fig. 1. The three brain areas. source: Big Commerce


Computational differences between spiking neural networks and previous ANNs

Rate-based-network is a specific implementation of the more general spiking-networks. One may see a rate-based-network as a spiking-network in which the inputs from each neuron are accumulated over a short time-period (think of "one second") and are used to update the state of their target neuron only once in each time-period.

For example, if an input neuron has an output of '40' in a rate-based-network, you should think about it as if it fire 40 times in the time-period, and only once in each time-period it's target neuron 'read' this input.

On the other hand, with spiking-neurons the output is limited to binary and hence the time-period used must be shorter than the maximal rate. In each time-period the target neuron updates its state based on it's (binary) input.

So to summarize:
* Spiking networks describe a more general phenomena.
* Spiking networks can react to inputs with fine temporal structure and act in time-periods which are order of magnitude smaller than rate-based-models.

Also one may add that spiking networks are likely to be more accurate biological description of the brain (but still a very rough account).


What is the mechanism behind "gut feelings"?

Intuition and implicit learning

I recommend you have a read through Lieberman's (2000) review and theory article on intuition.

Lieberman argues that intuition is a cognitive and behavioural consequence of implicit learning processes. Intuition is contrasted with more deliberate thought processes. It also reflects situations where it is often not possible to articulate the reasons for a decision or belief.

These links with implicit learning are extensive. Much of skilled performance is performed automatically without conscious effort. We also build extensive associations between stimuli and decision relevant information.
Furthermore, processes of learning can lead us to forget the reasons why something is true or why something is good, while retaining the fact that it is true or that it is good.

Lieberman suggests various neural components important to intuition:

  It is concluded that
  the caudate and putamen, in the basal ganglia, are central components of both intuition
  and implicit learning, supporting the proposed relationship.

Answering multiple choice questions

Your specific question concerns answering multiple choice questions.

One explanation of the phenomena you describe is that you may retrospectively analyse your feeling of doubt once you know the correct answer. You may dwell more on your feelings of doubt when you get an answer wrong, but presumably are less likely to do so on the questions where you had doubt but ultimately got the question right.

More generally, partial knowledge is not unusual when answering multiple choice questions. And presumably that feeling of uncertainty regarding the correct answer could come about by either deliberate reasoning or some intuitive unarticulated reason.

References

Lieberman, M. D. (2000). Intuition: a social cognitive neuroscience approach. Psychological bulletin, 126(1), 109. PDF


Clues for genetic basis in Autism Spectrum Disorders

There is a clear heritable component that seems to be "highly genetically heterogeneous and may be caused by both inheritable and de novo gene variations" (Rylaarsdam, Gomboa, 2019). There has been hundreds of genes implicated in autism and a complex interaction of non-heritable gene variations as well, "genetic modifiers such as copy number variation, single nucleotide polymorphisms, and epigenetic alterations likely play a key role" (Rylaarsdam, Gomboa, 2019).

The Rylaarsdam review article summarises the current state of play in terms of the genetic and non-heritable gene factors as well.

Reference:

Rylaarsdam, L., & Guemez Gamboa, A. D. (2019). Genetic Causes and Modifiers of Autism Spectrum Disorder. Frontiers in Cellular Neuroscience, 13, [385]. https://doi.org/10.3389/fncel.2019.00385


Cognitive explanation of why beta blockers are effective for anxiety

One possibility is related to the Two-Factor theory of emotion. The theory describes how emotion is a product of both cognitive and physiological factors. Essentially, the mind tries to determine what emotion it is feeling by analyzing the body. By antagonizing epinephrine, they kind of inhibit the sympathetic nervous system. So, when a person would otherwise feel anxiety it would be associated with the effect of epinephrine. Without that cue, they would possibly interpret their feelings differently, as feeling less anxious.

http://psycnet.apa.org/journals/rev/69/5/379/


What is meant by this line, "Much of Neisser’s critique of ﬁltering makes semantic rather than functional distinctions"?

Filter theory (see this also), specified that we could only attend to one input at a time (serial processing of stimuli as opposed to parallel processing, whereby you can attend to many stimuli at the same time), and this was originally put forward by Broadbent in 1959. The theory suggested that stimuli can be filtered based upon physical attributes, prior to full processing by the perceptual system.  The fact that there is the filter in place, in turn leads to some stimuli not raising attention. Plus, filter theory proposed that attention has a limited capacity due to the fact that you can only process one stimulus at a time.  This is where the bottleneck is, as you will be bombarded with lots and lots of stimuli and you can only process one of them at a time.

Neisser (1967) outlined a two-process theory that explained how much the filter affects attention (and hence consciousness). According to Neisser's theory, both the properties of the stimuli as well as semantic factors (language or logic), play a role in attention. Neisser argues for a constructive view of cognition in which perception is shaped by existing knowledge and hence attention is influenced by experience.

So therefore, when Cohen states that:

  Much of Neisser’s critique of ﬁltering makes semantic rather than functional distinctions.

he is stating that Neisser is, in most of his theory, purely making logical distinctions within filter theory rather than functional ones.

I interpret this to mean that, Neisser added the function of logic (through knowledge and previous experience) along with language, to the function of the stimulus filter.

References

Broadbent, D. (1958). Perception and Communication. London: Pergamon Press.

Neisser, U. (1967). Cognitive Psychology. New York: Appleton-Century-Croft.


What does "diffuse slowing" mean in the context of EEG and Alzheimer's?

Medscape defines diffuse as generalized, in the context of EEG. Generalized means activity recorded across large portions of the cortex. This opposes focal patterns, that occur locally. In turn this is reflected in generalized epilepsy and focal epilepsy. Generalized epilepsias are characterized by gross paroxysmal activity across the cortex, associated with a loss of consciousness. Focal epilepsy is localized in the cortex and stays restricted to one hemisphere and is not associated with a loss of consciousness.

Britton et al. (2016) explain generalized and focal slowing in the EEG as follows:

  The two main types of slowing are focal and generalized slowing. As
  previously discussed, generalized background slowing in the theta and
  delta frequency ranges is a normal finding on EEG when it represents
  developmental slowing [] or the evolution of drowsiness and sleep activity. However, when there is intermittent or persistent focal slowing seen consistently over one head region, or persistent, unvarying, and unreactive focal or generalized slow wave activity in a vigilant adult patient, this slow wave activity should be considered pathologic and indicates
  corresponding focal or generalized cerebral dysfunction or both.

Reference
- Britton et al. The Abnormal EEG. In: St. Louis & Frey (eds). Electroencephalography (EEG): An Introductory Text and Atlas of Normal and Abnormal Findings in Adults, Children, and Infants. Chicago: American Epilepsy Society; 2016


In psychiatry, what does double-bookkeeping mean?

Within Psychiatry and psychology, Double Bookkeeping, also known as Double Entry Bookkeeping is not quite the same as double entry bookkeeping within accountancy.  Within Psychiatry and Psychology, it refers to the tendency, among those who experience delusions, to perceive both the reality and the delusions as being real. There are discrepancies or inconsistencies between the two within psychiatry which the affected person may not be bothered about, whereas within accountancy, the two entries made in different parts of accounts records are there to reconcile the records and ensure there are no discrepancies or inconsistencies.

Example Accountancy Double Bookkeeping

The main accounts ledger may have a record of a transaction paying $100.00 towards a dept to Debt and Renters Ltd.

Meanwhile another entry will be made in the debts record for Debt and Renters Ltd. stating that on the same date in the main ledger, \$100.00 has been taken off the debt, with the running balance remaining being $100.00 less than previous.

All records reconcile, showing no discrepancies or inconsistencies.

In psychiatry and psychology

Swiss psychiatrist and eugenicist, Eugen Bleuler in Dementia Praecox or the Group of Schizophrenias (his 1911 seminal study, translated from German into English in 1950 by Joseph Zinkin) said on pages 56:

  It is especially important to know that these patients carry on a kind of “double-entry bookkeeping” in many of their relationships. They know the real state of affairs as well as the falsified one and will answer according to the circumstances with one kind or the other type of orientation—or both together. This last is especially frequent in mis(-)recognizing people: the physician “is now here as Dr. N.,” at other times he becomes the former lover.

With this, "Dr. N." is both a former lover and their physician whilst in reality, Dr. N. was never their lover.  Without the ability to carry out reality checking efficiently, they can refer to either or both as being true.

In accounts ledgers terms there are two entries in the person's main record within the mind recording the facts concerning Dr. N. without a strong second record to refer to regarding the person's past lovers.

Jeneen Interlandi, wrote in The New York Times Magazine (2012)

  While we waited for the doctor to evaluate him, my father did what mental health professionals refer to as double-bookkeeping. He remembered most of what transpired earlier in the day but still believed he was in the hospital to have his pacemaker checked.

References

Bleuler, E. (1950). Dementia praecox or the group of schizophrenias. Oxford, England: International Universities Press.

Interlandi, J. (2012). When My Crazy Father Actually Lost His Mind - New York Times MagazineAccessible from: http://www.nytimes.com/2012/06/24/magazine/when-my-crazy-father-actually-lost-his-mind.html

See also

Bortolotti, L., & Broome, M. R. (2012). Affective dimensions of the phenomenon of double bookkeeping in delusions. Emotion Review, 4(2), 187-191.
DOI: 10.1177/1754073911430115

and

Carruthers, B. G., & Espeland, W. N. (1991). Accounting for rationality: Double-entry bookkeeping and the rhetoric of economic rationality. American journal of sociology, 97(1), 31-69.
DOI: 10.1057/9780230304253_12


Peter Carruthers  argues (2014) that system 1 doesn't quite overlap with unconscious thinking:

  I shall argue that there is, indeed, a real, scientifically valid, distinction between a set of
  intuitive, unconsciously operating reasoning systems, on the one hand, and a reflective system
  whose operations are partly conscious, on the other. But I shall argue that this division fails to
  line up with many of the other properties generally associated with Systems 1 and 2. In
  particular, some intuitive systems can be slow, some can be controlled, and some can approach
  the highest normative standards; so the moniker «quick and dirty» is certainly inappropriate
  when applied to intuitive reasoning as such.

And Jonathan Evans (2014), a dual-process theorist but also strong critic of UTT, writes:

  It is true
  that the distinction between conscious and nonconscious processing
  has been emphasised by some social psychologists (e.g.,
  Wilson 2002), but it is emphatically not the foundation for contemporary
  dual-process theories of reasoning and decision
  making. As a dual-process theorist, I have argued, in common
  with others, that the conscious/unconscious decision cannot be
  the basis for the dual-process distinction because it is too vague
  and fails to define the key central properties of dual processing
  (Evans & Stanovich 2013). I should also point out that in spite
  of defending the validity of much of the research that N&S criticise
  here, I have in common with them critiqued unconscious
  thinking theory and other strong assertions of the powers of intuition
  (see Evans 2010, Ch. 4). This is because dual-process theory
  confines powers of reflective reasoning – and with it the ability to
  deal with novel and difficult problems – to Type 2 processing.
  The case for dual process is in fact based not on the conscious/
  unconscious distinction but on the claim that there are two forms
  of cognitive processing which have distinctive properties and
  which reflect the operation of distinct cognitive and neural
  systems. Most of these properties are merely typical correlates,
  and few are defining features (Evans & Stanovich 2013). I agree
  with Stanovich that Type 2 processing is distinguished both by
  its cognitive resources (central working memory, correlation
  with measures of cognitive capacity) and by its ability to engage
  in cognitive decoupling and hypothetical thinking. The apparent
  link of dual-process theory with consciousness comes only from
  the fact that some of the items attended in working memory are
  available to verbal report. But using broader definitions of consciousness,
  I have argued in detail that both Type 1 and Type 2
  thinking have aspects that are conscious as well as unconscious
  (Evans 2010, Ch. 7).
  In conclusion, not only do I reject the authors’ presumption of
  conscious decision making, which I believe to be shakily founded
  on folk psychology, but I also contest their implication that the
  conscious/unconscious distinction is the basis for contemporary
  theories of dual processing in higher cognition.


People who kill themselves usually believe that they are in an unbearable situation from which they cannot escape and that things won't ever get better.
The problem with research into the reasons for suicide is that those that successfuly killed themselves can no longer explain their motives, and those that survived might – consciously or unconsciously – have planned not to die, so their motivations might not be motivations to die but motivations to affect others or to relieve tension (similar to non-suicidal self-injury).
A close friend who only accidentally survived a suicide attempt (because, not being a physician or apothecary, she had unknowingly chosen sleeping pills that cannot kill you, no matter how many you take) had been abused as a child, consequently lost all self-worth, felt she would never experience love and happiness, and finally tried to end her misery when she was 21. Her survival was followed by another, successful, suicide, which to me shows that her first attempt was earnest.
This is the only person I know who wanted to die and told me her reasons, between the two attempts. More abstractly, her reason was the one stated at the beginning of my answer: not simple depression or hopelessness. We all go through such phases, but we know they pass, so we bear them and wait for better times. This person had been depressed and miserable for so long, that she could no longer imagine things changeing for the better. Unable to bear the idea of having to endure another eighty years of unhappiness, she ended it.
There is some research into reasons for suicide, which, as far as I know, does not emphasise this point and thus fails to explain why some people kill themselves in a moment of hopelessness, while others don't. For example, Brown, Comtois and Linehan (2002) interviewed women who attempted suicide and compared their motivations to women who performed non-suicidal self-injury. Their abstract summarizes (my emphasis):

Overall, reasons given for suicide attempts differed from reasons for nonsuicidal self-injury. Nonsuicidal acts were more often reported as intended to express anger, punish oneself, generate normal feelings, and distract oneself, whereas suicide attempts were more often reported as intended to make others better off. Almost all participants reported that both types of parasuicide were intended to relieve negative emotions. It is likely that suicidal and nonsuicidal parasuicide have multiple intents and functions.

Some old people who ask physicians for assisted suicide report that they don't want to burden their families. I think it is a true reason for some people, while others would probably rather want to live, if they could stop being debilitated by old age. Again, the underlying reason is that these people feel they cannot change their situation to the better. Borderline women might feel the same, since their emotional instability, inability to have functioning relationships, fear and depression, are not momentary but have usually been there for all their adult lives, often as effects of some trauma such as childhood abuse.
Adolescents, who are often thought to be more self-centered and less socially concerned in their motives than old people, also report more self-centered reasons to kill themselves. In their study of adolescent suicide, Boergers, Spirito and Donaldson (1998, my emphasis) found that

Consistent with prior research, the most frequently endorsed motives for self-harm were to die, to escape, and to obtain relief. More manipulative reasons for overdose (such as making people sorry) were endorsed less frequently. Adolescents who cited death as a reason for their suicide attempt reported more hopelessness, socially prescribed perfectionism, depression, and anger expression.

With the restriction that we don't know who of the suicide attempters really wanted to die, nevertheless for most of them the primary reason was to end a life they had no hope of changing to the better.
Because what does it mean that you feel you are not perfect enough? For adolescents it usually means that you feel you are so ugly no one will ever love you, or that you are introverted and cannot make friends and have been outside the ingroup for so long that you no longer believe that anyone will ever love you. It does not matter if other, less pretty people, can be happy, or if other loners can make loner friends, the important aspect is that you feel you are not good enough to be loved by those that you want to love you and that nothing you ever do (makeup, bringing home good marks) can change that, because in truth, for example, it is not actually you who are unlovable but your parents who are unable to love you because of their own mental disorders (and that is how some of them are passed on through the generations).
Studying successful suicides, Cavanagh, Carson, Sharpe and Lawrie (2003) found that

mental disorder was the most strongly associated variable of those that have been studied. ... Suicide prevention strategies may be most effective if focused on the treatment of mental disorders.

This is of course a very global result, but it shows that people don't usually kill themselves because they experience dire circumstances or a bad phase in their lives, but only if their long term mental well-being is destroyed.
Linehan, Goodstein, Nielsen and Chiles (1983) have studied the reasons why people do not kill themselves. The primary reasons for living, if suicide was contemplated, were:

Survival and Coping Beliefs, Responsibility to Family, Child-Related Concerns, Fear of Suicide, Fear of Social Disapproval, and Moral Objections.

Besides fear (of dying and death and the judgment of God and men) and responsibility for family and children, the main reason to keep people alive was their belief that they could survive and cope! If we turn this around, the main reason to die (besides having no responsibility and not being afraid, or overcoming those concerns) is the belief of not being able to cope.
What makes you kill yourself, in sum, is that you can no longer take it and believe you cannot change it. Very simple – and horribly tragic.

Sources:

Boergers, J., Spirito, A., & Donaldson, D. (1998). Reasons for adolescent suicide attempts: Associations with psychological functioning. Journal of the American Academy of Child & Adolescent Psychiatry, 37(12), 1287-1293.
Brown, M. Z., Comtois, K. A., & Linehan, M. M. (2002). Reasons for suicide attempts and nonsuicidal self-injury in women with borderline personality disorder. Journal of abnormal psychology, 111(1), 198.
Cavanagh, J. T., Carson, A. J., Sharpe, M., & Lawrie, S. M. (2003). Psychological autopsy studies of suicide: a systematic review. Psychological medicine, 33(03), 395-405.
Linehan, M. M., Goodstein, J. L., Nielsen, S. L., & Chiles, J. A. (1983). Reasons for staying alive when you are thinking of killing yourself: the reasons for living inventory. Journal of consulting and clinical psychology, 51(2), 276.


Pstnet, the editor of Eprime, does not provide a sample for oddball paradigms. And sharing Eprime scripts is rare but you may find a script of interest here

http://www.nitrc.org/frs/download.php/283/AO_version110804.zip

This is part of an initiative described at http://www.birncommunity.org/resources/tools/fire-primer/multi-site-cognitive-paradigms-for-fmri-studies. File summaries are here http://www.nitrc.org/projects/fbirn (click on "see all files"). This auditory oddball file is far from being a sample though.


What does double dissociation really tell us?

Double dissociation does not prove the independence of certain cognitive functions and their neural substrates. What it does is provide stronger evidence for which the best explanation is the independence of certain neurocognitive systems.
The brain is on many aspects not a marvel of engineering with many areas being responsible for a spectrum of functions and behaviours or for different aspects of a seemingly unitary cognitive faculty. On top of that, it is often difficult to make a proper classification and distinction between certain functions and behaviours (examples are episodic/semantic memory and perceptual/semantic priming) which, in many cases, limits the validity of the conclusions drawn.

So I don't know if a "conclusive demonstration" is possible. However, under properly defined terms, a double dissociation can provide strong support for independence with little possibility of an intersection between neurocognitive systems because if an intersection existed, it would be highly possible for a function to be retained at some level even after the hypothetical brain system responsible for it, suffers a lesion.


Can a person be hypnotized to act drunk?

Yes (video example of Derren Brown making a man drunk) with caveats:

Not for every person being drunk means loosing his inhibitions
You can't force people to do something they don't want to do (example by Anthony
Galie)


What are ways to explore metamathematics from a cognitive science/neuroscience lens?

You'll be interested in Where Mathematics Comes From, by George Lakoff and Rafael E. Núñez. Lakoff & Núñez argue that all of our mathematical concepts are based on some kind of conceptual metaphor, where we take the rules of a domain that we understand intuitively and apply them into a new, mathematical context. For example, the concept of "motion along a path" gives us the concept of a number line, which in turn provides a natural way to think about negative numbers:

Moreover, this metaphor provides a natural extension to negative numbers - let the origin be somewhere on a pathway extending indefinitely in both directions. The negative numbers will be the point-locations on the other side of zero from the positive numbers along the same path. This extension was explicitly made by Rafael Bombelli in the second half of the sixteenth century. In Bombelli's extension of the point-location metaphor for numbers, positive numbers, zero, and negative numbers are all point-locations on a line. This made it commonplace for European mathematicians to think and speak of the concept of a number lying between two other numbers - as in zero lies between minus one and one. Conceptualizing all (real) numbers metaphorically as point-locations on the same line was crucial to providing a uniform understanding of number. These days, it is hard to imagine that there was ever a time when such a metaphor was not commonly accepted by mathematicians! (Lakoff & Núñez, p. 73)

Lakoff & Núñez explicitly argue that all of human mathematics is created by the application of human-specific cognitive machinery and culture, and that the mathematics of an alien species might look very different.
The following references might or might not be useful for purposes of metamathematics, but mentioning them anyway since I happen to have them at hand from a course on number cognition that I took some years back: Piazza et al. (2007) and Brannon (2006) on how numbers are represented in the brain, Carey (2004) on how children come to learn the concept of integers, Frank et al. (2008) on numbers as a cognitive technology, and Gallistel et al. (2006) for an argument that real numbers rather than integers are what the brain represents.
Personally I also think that an extraordinarily interesting paper is Dehaene & Cohen (2007), which argues that the existence of specialized neuronal circuitry for purposes such as arithmetic and reading is possible because our culture has managed to "hijack" pre-existing circuits which originally evolved for other purposes:

The neuronal recycling hypothesis consists of the following postulates:

Human brain organization is subject to strong anatomical and connectional constraints inherited from evolution. Organized neural maps are present early on in infancy and bias subsequent learning.

Cultural acquisitions (e.g., reading) must find their “neuronal niche,” a set of circuits that are sufficiently close to the required function and sufficiently plastic as to reorient a significant fraction of their neural resources to this novel use.

As cortical territories dedicated to evolutionarily older functions are invaded by novel cultural objects, their prior organization is never entirely erased. Thus, prior neural constraints exert a powerful influence on cultural acquisition and adult organization.

If you accepted these postulates, then arguably the neural constraints of the older circuits might considerably bias the way that human mathematics is carried out.
References
Brannon, E.M. (2006) The representation of numerical magnitude. Curr Opin Neurobiol. Apr 2006; 16(2): 222–229. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1626588/
Carey, S. (2004) Bootstrapping & the origin of concepts. Daedalus, Winter 2004. http://hum.uchicago.edu/ck0/kennedy/classes/s09/experimentalsemantics/carey04.pdf
Dehaene, S. & Cohen, L. (2007) Cultural Recycling of Cortical Maps. Neuron, Volume 56, Issue 2, Pages 384–398. http://www.sciencedirect.com/science/article/pii/S0896627307007593
Frank, M.C. & Everett, D.L. & Fedorenko, E. & Gibson, E. (2008) Number as a cognitive technology: Evidence from Pirahã language and cognition. Cognition 108, 819-824. http://www.letras.ufrj.br/poslinguistica/recursion/papers/18-frank-et-al.pdf
Gallistel, C.R. & Gelman, R. & Cordes, S. (2006) The Cultural and Evolutionary History of the Real Numbers. Culture and evolution. Cambridge, MA: MIT Press. http://hum.uchicago.edu/ck0/kennedy/classes/s09/experimentalsemantics/gallistel-etal05.pdf
Lakoff, G. & Núñez, R.E. (2001) Where Mathematics Come From: How The Embodied Mind Brings Mathematics Into Being. Basic Books.
Piazza, M. & Pinel, P. & Bihan, D.L. & Dehaene, S. (2007) A Magnitude Code Common
to Numerosities and Number Symbols in Human Intraparietal Cortex. Neuron 53, 293–305. http://www.sciencedirect.com/science/article/pii/S0896627306009895


What decision problems are better answered with analytic thinking, and what are better answered with intuition?

Keith Stanovich summaries a school of thought on this debate nicely in his review of Kahneman's 'Thinking, Fast and Slow'.

Essentially, system 1 excels in 'benign' environments, where the cues that system 1 is adept at using are reliable indicators of the true state of the world, and no one else is trying to manipulate you by faking these cues.
System two is necessary in 'hostile' environments, either because the relationships between cues and reality have changed from what system 1 expects (and has come to expect through natural selection: for millions of years, these cues were reliable), or because there are other agents who are manipulating these cues deliberately (Stanovich cites 'advertisements,
or the deliberate design of supermarket floorspace to maximize revenue').

In a similar vein, Gerd Gigerenzer, although not strictly speaking a dual process theorist, has long argued the positive role of heuristics (as opposed to the 'heuristics and biases' approach).  His main claim is that simple, automatic decision rules often outperform more complex reasoning, or even statistical approaches like linear regression.

His examples include:

A recognition heuristic - whatever the decision (predicting elections, sports, stock performances, consumer behaviour, etc.), the response you recognize is more likely to do well than the one you don't.
Fluency - If you recognize both, the one that was easier to recognize will do better.
If you're not presented with multiple choice responses, the first response to come to mind is likely the best.
One-reason choices - it's more effective to rely on one reliable cue than to analytically compute all the available information (example: running to catch a high ball, try to modulate your speed to keep the angle between the ball and the ground constant).

There's plenty more in this review (warning: paywall).

Finally, a really interesting recent approach has been to compare decisions 'made by the head' to analogous choices 'made by the hand', or in other words, design fast, action-based analogues to classic decision making tasks (see this review).

I'll not go into details here, but essentially, we're extremely good at intuitively computing the probabilities involved in executing movements under uncertainty, presumably because mammals have been doing it for millions of years, but can be pretty awful at explicitly working out the right strategy for the same problem.

In summary, **automatic, innate, intuitive processes work well for the evolutionary old tasks they were designed for, like movement planning, and a lot of real world decision making (for a certain value of 'designed': natural selection, etc.), but can lead up astray in evolutionary novel situations that human culture places us in, ranging from supermarkets, to psychology labs.

Hope this helps, sorry about the rambling!


How to test for malingering in criminals trying to deny capacity for criminal responsibility?

More comprehensive ones than the abovementioned memory test include the Miller Forensic Assessement of Symptoms and the Structured Interview of Reported Symptoms. These assess a wide variety of psychiatric symptoms and are supposedly very hard to fake.


How does cognitive science explain the origins of intuition and intelligence, that accurately describes the laws of nature?

A couple of other interrelated perspectives are presented below.

The first perspective comes from the article Artificial Intelligence, Logic of Discovery and Scientific Realism (Alai), where they state, using scientific discovery as an example (as per the example in the question), that

  if the process of
  discovery is rational, mustn’t it therefore follow rational criteria and rules, hence a
  logic? On the other hand, it is well known that chance, luck, and insight often play an
  important role in discovery.

Effectively, almost like a case of someone 'tripping over' the final piece of their theorem.  The author goes further, contending that if their were a rational set of steps, thus

  if
  discovery were just a matter of rule following, why couldn’t anyone learn the necessary rules and become a great scientist? Or why couldn’t the scientists themselves just follow
  the logic of discovery and program in advance new discoveries, and rapidly achieve
  such results as a cure for cancer, or the cold fusion of atom, which while sorely needed
  still elude the efforts of researchers?

Meaning, according to this article's perspective, that luck, chance and insight play a major role.

The final factor, insight, is alluded to in the website Einstein's Pathway to Special Relativity (Norton), taking the example scientist from the question, Albert Einstein and how he developed, for example, the Theory of Special Relativity, which started when

  he began to think about ether, electricity, magnetism and motion.

Essentially, he had insight by

  pondering these developments that led Einstein to discover the
  special theory of relativity in 1905.

A key point made is that

  The discovery was not momentary.

This is crucial, the ideas didn't just 'pop' into his head, the theory was the outcome of having learned and developed an insight in the background information, latest developments in relevant disciplines and of course,

  in Einstein's own reckoning, seven and
  more years of work.

As an independent researcher, (and I am not comparing myself to Albert Einstein), the discoveries that I have found, have had successfully peer reviewed and have been published come from having some specific insight, through background reading, training, education etc, to topics and skills required relevant to the discovery, as well as a lot of work to bring these insights together with new observations to make a discovery.


To what extent do individuals vary in their ability to mentally visualise?

Short answer: there appears to be a whole range of ability at the task of mental visualization. Based on what I have found on the Web, your own level of ability is fairly unusual. Your friend's level of ability, by contrast, seems to be fairly common. Sources I found on this were fairly sparse, though, and my conclusions should not be relied on too heavily.

The Wikipedia article on "Closed-eye hallucination" seems to have some problems, but is helpful on this question. It describes five distinct levels of "Closed-eye visualization."

Levels 1 and 2 correspond to very little visual information.
Level 3 is "patterns, motion, and color."
Level 4, "objects and things," appears to correspond to your experience.
Level 5 describes impressions not immediately distinguishable from reality.

  Level 1 and 2 are very common, and often happen every day. It is still
  normal to experience level 3, and even level 4, but only a small
  percentage of the population do this without psychedelic drugs,
  meditation or extensive visualization training.

Wikipedia also links an old paper in Psychological Review that studied variations in the ability to willfully shape closed-eye perception, describing what seems to be a wide distribution of ability:

  Of the sixteen persons experimenting with themselves, four only
  reported no success; nine had a partial success which seemed to
  increase with practice and which they considered undoubtedly dependent
  directly upon volition; and with the remaining three the success was
  marked and really phenomenal.

I seem to remember that there was an early debate in psychology about whether it was possible to mentally visualize images. Some scholars insisted that it was, others were adamant that it wasn't. Today we can dissolve the debate because we know it is possible for some but not for others. Unfortunately, I can't find a source for this story online.

There is also an old debate in philosophy over the role mental imagery plays in cognition. For some early thinkers, an "idea" was a visual mental image; other philosophers questioned whether actual images were so important. For an overview of the debate you can consult the topic "Mental Imagery" in Stanford's Encyclopedia of Philosophy. The mental imagery debate is not really the same thing as what you're asking about, but participants sometimes seemed to be debating whether it was even possible to "see" mental images.


Is it possible for a human to feel no emotion?

It is a physical possibility but you need, at the bare minimum, to feel for your self to survive; like the need to eat. If you don't want to call hunger and similar things for feelings it would be a problem anyway because discus is what make you avoiding eating bad or toxic food and fear to avid getting eaten etc.

scorce: http://atlasofemotions.org/#continents/disgust

What you most likely have heard is that psychopaths don't feel anything and that is not true. They do care abut them self and others in self interest but would not start crying for anyone from feeling empathy.  (I don't have a source for the later part but you can test it with a mind experiment with a psychopath and a smaller guy that tries to piss of the psychopath. Per definition the psychopath don't care if he kills the other dude but if he do he will end up in jail) http://www.dictionary.com/browse/psychopath

(Sorry for the horrible English, was a while since I last wrote anything)


Is good short term memory correlated with good long term memory?

There is a functional dissociation between short and long-term memory.

It was observed by Milner (1966) that a patient (case H.M) can have a normally working short-term memory with an impaired long term one; and by Shallice & Warrington (1970) that a patient (K.F.) can have correct long-term memory performance while a severe impairment in short-term memory.

So there is no simple relationship between the two, if at all. Nevertheless, it could be a correlation but probably mediated by other factors such as attentional processes, explicit learning strategy etc.


is it true that people who code think differently?

Well, let's considering what you're asking here.

You're asking if people who code think differently. Well, let's consider those who know how to program. Some people plan what they are going to do, while others take a more dynamic approach. Some people create a 'skeleton' of what they are about to build before they fill in the missing pieces (and will debug each piece as they go), and yet others will create one new method at a time until they have one giant bug-filled product to deal with at the end.

Now pick two arbitrary coders. Do they think differently from each other? Probably. They probably have different approaches, interests, strengths, and weaknesses. But sure, they probably think differently than, say, someone who works in a grocery store.

But then again, take the person who works in a grocery store. They probably have different methods for dealing with shoppers, they probably use different greetings, they may have different strengths and weaknesses, etc.

In fact, I would argue that in instances where you are given a choice, it isn't what you do that teaches you to think; rather, the way you think determines what you do. You may pick up on certain methods out of habit (maybe you see people as variables, or maybe you're quick to decompose your thoughts like you would a program), but on top of learning new skills, those habits you pick up are probably further emphasizing the ways in which you currently think.


Why do scientists say brains are faster than computers?

Have you ever seen IBM's Watson? Watson is composed of a cluster of ninety IBM Power 750 servers, each of which uses a 3.5 GHz POWER7 eight core processor, with four threads per core. In total, the system has 2,880 POWER7 processor cores and has 16 terabytes of RAM. It must be kept in a (very) large refrigerated room.

  Watson is a question answering (QA) computing system that IBM built to apply advanced natural language processing, information retrieval, knowledge representation, automated reasoning, and machine learning technologies to the field of open domain question answering. According to John Rennie, Watson can process 500 gigabytes, the equivalent of a million books, per second.

Watson's official debut was on the game show Jeopardy, where it was pitted against two of Jeopardy's best players. It won, but the humans gave it a run for its money. Most believe the win was more due to Watson's faster response time (it was electronically keyed into the buzzer; Watson could activate the buzzer within about eight milliseconds, whereas the human response time to the go ahead light signal is several tenths of a second. In addition, to access memory more quickly, content was stored in Watson's RAM for the game because data stored on hard drives are too slow to access.

Watson was devised as a medical diagnostician (as well as other applications). With many years, scores of technicians, who knows how many billions of dollars, and access to medical encyclopedias, books, medical journals and the internet, it can outperform third year medical students in only one area: oncology (and even then, only lung, prostate and breast CA).

So, one average medical resident (4 years of medical school, and, say, second year of residency) can outperform a very, very fast medical supercomputer 99% of the time. I specialize in Primary Care medicine: Family and Emergency Medicine. With a few exceptions per year, within minutes of initiating a conversation with a patient, by watching the patient, reading his vital signs, and hearing answers to perhaps a dozen questions, I already have narrowed down my diagnoses to 2 or 3 top candidates and several other lesser considerations. I am one individual with one brain which accesses only to the information to which I've been exposed, yet I will outperform a medical supercomputer >99% of the time. In under 10 minutes. (This does not mean that I only spend 10 minutes with a patient. Medicine is about more than the correct diagnosis.)

This is Watson:

My brain is about the size of the "W" etched on the room's window.

You tell me: Which is "faster", a supercomputer or a human brain? It really does depend on your definition of "faster", doesn't it?

References:
Wikipedia
Putting Watson to Work: Watson in Healthcare. IBM.
IBM's Watson is better at diagnosing cancer than human doctors
IBM Watson's impressive healthcare analytics capabilities continue to evolve


Does the fusiform face area in patients with Prosopagnosia (face blindness) show lower activity under an fMRI?

It is not widely thought that impaired function or destruction of the fusiform is sufficient to produce prosoganosia. It is currently widely held that face processing involves a network of regions in the occipital and temporal lobes (e.g., the occipital face area, posterior superior temporal sulus, anterior superior temporal sulus, anterior collateral sulcus). For example, Bruno Rossion reports a patient with prosopagnoisa who has widespread damage to bilateral occipital and temporal brain regions but with a spared right FFA. Moreover, work by Marlene Behrmann has shown that people with developmental prosopagnosia have disrupted connections between the posterior temporal lobes (ie near the FFA) and the anterior temporal lobes. This is significant because there is growing evidence that there may be face selective regions in the anterior temporal lobes and that they are more directly involved in face recognition. Moreover there is some evidence that this anterior temporal region modulates the activity in the FFA (Nestor, Plaut, Behrmann, 2011 PNAS). So it might very well be that the FFA does show decreased activity in a face recognition task, but this might be due to impaired feedback to this region. On this view, lower activity in FFA is the effect of prosopagnosia not the cause, so making comparisons on levels of activity within one region might not be as meaningful as you think.

References

Nestor, A., Plaut, D.C., & Behrmann, M. (2011). Unraveling the distributed neural code of facial identity through spatiotemporal pattern analysis. Proceedings of the National Academy of Sciences, 108, 9998. LINK


Can authority urge person to commit suicide?

I believe that this has been proven by history and is also happening in the present world. During World War 2, there were (1)kamikaze pilots. In today's world, there are (2)suicide bombers.
(1) Kamikaze - This was a direct order to Japanese pilots from their authorities to kill themselves and take out as many of the enemy as they could.
(2) Suicide bombing - This too is a direct order from religious authorities.
It can also be argued that culture is an "authority". Culture is passed down from elders who are authority figures. In Japan, there was Seppuku. Samurai who were captured would disembowel themselves, because their culture dictated that this was the honorable thing to do.
I hope I understood your question correctly and was able to answer it.


How similar are human brains within the same haplogroup?

The following comes from my research experience using fMRI to study the human visual system.

Overall, peoples brains are similar to each other on higher scales, and become very different from each other as the scale becomes smaller.

Differences between different people start with brain size and sulci patterns. Also male and female brain anatomies will be slightly different.

Wiring patterns within same brain regions will be similar between people, but as you get to individual neurons, it starts to look very chaotic. Dendrites will have stereotypical tree shapes for certain neurons (i.e. Pyramidal cells), but individual branches will be somewhat randomly distributed within their stereotypical areas.

As you get to the synaptic receptor/ion channel level, their distribution will be even more chaotic. Keep in mind the receptors themselves will behave stochasticaly, opening and closing based on when a particular ligand molecule binds to them.

The anatomical shapes of the brains will be mostly based on genes, so people within the same haplogroup should have brain anatomies slightly more similar than general population, but even those should have individual variations. Dendrite and receptor distribution generally depends on learning, so people with different initial conditions and environments during development will have dendrites wired differently.

I think the most fascinating aspect of these differences is that human minds are essentially slightly different neural networks that perceive the world in their own slightly different ways. The closer the genes and development environment between two people, the more similar will be their perceptions of the world.


How do I measure ratio of EEG frequency band for a few electrodes in decibels?

Decidels are ratios in log scale. Usually the ratio of powers (in the physical sense). Powers sum up, but not dB. For example, a sound source at 70dB SPL means its power is approximately 3200 times higher than the reference sound source of dB SPL. If you have 2 sound sources both at 70dB, their power add up but their total sound pressure is going to be only 76dB SPL.

The appropriate way to answer your question depends on the assumptions you make. Your first equation compares the overall power within the Theta frequency band to the overall power within the Beta band, across recording locations. Your second equation compares power ratios at each location independently (although I would take the mean, not add them). Whether the first or the second equation is more appropriate is a scientific question.

Also note that dBs are usually defined in log10 scale ($\frac{ln(x)}{ln(10)}$), but it doesn't really matter.


How do neuro transmitters interact with neurons in the brain?

Actually it's a bit complicated but in simple terms :

Neurotransmitters are stored in a synapse in synaptic vesicles, clustered beneath the membrane in the axon terminal located at the presynaptic side of the synapse. Neurotransmitters are released into and diffused across the synaptic cleft, where they bind to specific receptors in the membrane on the postsynaptic side of the synapse.

Most neurotransmitters are about the size of a single amino acid, however, some neurotransmitters may be the size of larger proteins or peptides. A released neurotransmitter is typically available in the synaptic cleft for a short time before it is metabolized by enzymes, pulled back into the presynaptic neuron through reuptake, or bound to a postsynaptic receptor. Nevertheless, short-term exposure of the receptor to a neurotransmitter is typically sufficient for causing a postsynaptic response by way of synaptic transmission.

In response to a threshold action potential or graded electrical potential, a neurotransmitter is released at the presynaptic terminal. Low level "baseline" release also occurs without electrical stimulation. The released neurotransmitter may then move across the synapse to be detected by and bind with receptors in the postsynaptic neuron. Binding of neurotransmitters may influence the postsynaptic neuron in either an inhibitory or excitatory way. This neuron may be connected to many more neurons, and if the total of excitatory influences are greater than those of inhibitory influences, the neuron will also "fire". Ultimately it will create a new action potential at its axon hillock to release neurotransmitters and pass on the information to yet another neighboring neuron.


NEO FFI Scoring

The test manual describes how to calculate raw scores for the NEO-FFI. If you have been asked to do an analysis of the NEO-FFI then you should be given access to relevant details in the test manual. If you don't have access, you may wish to contact your local psychology department. They will often have a test library with the NEO-FFI manual. Alternatively, you can contact a test distributor, although there are often educational requirements in order to be allowed to purchase such a manual.

This website seems to provide a web description of how to obtain raw scores for the NEO FFI. For norm referenced scores such as t-scores, presumably you would need access to norm tables supplied in the test manual. One exception would be where you are using your own sample norms as the distribution. In this case of t-scores, you would convert raw scores to z-scores and then multiply by 10 and then add 50. See for example this article on standard scores.

General scoring advice

In general, when scoring psychological tests, the most common approach is to use a unit weighted sum or mean of items after item reversal. I have a post that describes this in more detail with reference to SPSS and R. So, you simply need to know which items belong to which scales and which items need reversing.


Looking for references discussing aspect of human/animal adaptivity and its pertaining computational objectives

Dynamic systems analysis has recently made inroads into psychology.  Quirin et al.(2020) consider adaptive processes and may be a place for you to start.
Quirin, M., Robinson, M. D., Rauthmann, J. F., Kuhl, J., & Deyoung, C. G. (2020). The Dynamics of Personality Approach (DPA): Twenty Tenets for Uncovering the Causal Mechanisms of Personality. European Journal of Personality. https://doi.org/10.1002/per.2295


Are there psychological explanations for people being drawn to neo-nazism or other bad ideologues?

There are a few questions here which are related:

How does people's sense of right and wrong affect their behavior?
Any research on brain's processes involved in evil actions?

I will try and put some time aside to build a more full answer with references, but to give a starter, there are a lot of studies on this subject starting with conformity studies such as the Milgram Experiment (here is a documentary on the experiment) and the Stanford Prison Experiment.

Philip Zimbardo who was in charge of the Stanford Prison Experiment wrote the book "The Lucifer Effect: Understanding How Good People Turn Evil" and led a talk on his research on the subject including other examples, but the biggest one for me was turned into a movie in Germany called Die Welle, and in English under the name The Wave.

The movie covered the true story of an experiment with a group of school children who wanted to understand the very same question you are asking, not believing it could happen today.  Things turned nasty and out of control.

Teacher, Ron Jones's "Third Wave" experiment, which took place at a Californian school in 1967 was put together to explain how the German population could accept the actions of the Nazi regime during the Second World War. He founded a totalitarian, strictly-organized "movement" with harsh punishments that was led by him autocratically. The intricate sense of community led to a wave of enthusiasm not only from his own students, but also from students from other classes who joined the program later. Jones later admitted to having enjoyed having his students as followers. To eliminate the upcoming momentum, Jones aborted the project on the fifth day and showed the students the parallels towards the Nazi youth movements.

Image: Cutting of Klink (1967)

All of these studies and experiments provide strong proof that the risk of full Nazi style regimes can return on a national level given the right circumstances.

References

Klink, B. (1967). 'Third Wave' presents inside look into Fascism. Catamount, 11(14), 3Retrieved at: http://www.cubberleycatamount.com/Content/66-67/Catamount%20Pages/V11No14

See Also

Lesson Plan MovieThe documentary by the students and teacher of “The Third Wave” (aka “The Wave”)(http://www.lessonplanmovie.com)

Teacher, Ron Jones' account of the experiment(http://libcom.org/history/the-third-wave-1967-account-ron-jones)


Why do we wake up when we die in our dreams?

When you dream you're in REM sleep (rapid eye movement). REM sleep is only slightly more "deep" than stage 1 of non-REM which means it's not that hard to wake you up in the first place.

Dying in a dream is a stressful event, which causes your brain to release adrenaline. You can't sleep and have an adrenaline rush at the same time so you wake up.

These dreams where you die and wake up are usually more memorable due to the fact that you wake up whereas most people don't remember 95% of their dreams.

Sources:

Adrenalin:

"Being particularly scary or threatening, nightmares can provoke ‘fight and flight’ responses, and the release of adrenalin whilst we are still asleep. Once you awaken from a nightmare it may then take a little time to come down from this elevated state, preventing you from being able to get back to sleep as easily or quickly."

https://www.youtube.com/watch?v=9TZOiC23CpI&feature=youtu.be

Profeso Colin Espie, Director of the Sleep Centre at the University of Glasgow and co-founder of Sleepio

Forgetting Dreams:

"We forget almost all dreams soon after waking up. Our forgetfulness is generally attributed to neurochemical conditions in the brain that occur during REM sleep, a phase of sleep characterized by rapid eye movements and dreaming. But that may not be the whole story.
Perhaps the most compelling explanation is the absence of the hormone norepinephrine in the cerebral cortex, a brain region that plays a key role in memory, thought, language and consciousness. A study published in 2002 in the American Journal of Psychiatry supports the theory that the presence of norepinephrine enhances memory in humans, although its role in learning and recall remains controversial."

http://www.scientificamerican.com/article/why-do-memories-of-vivid-dreams/

"At least 95% of all dreams are not remembered. Certain brain chemicals necessary for converting short-term memories into long-term ones are suppressed during REM sleep. Unless a dream is particularly vivid and if one wakes during or immediately after it, the content of the dream is not remembered"

Hobson, J.A.; McCarly, R.W. (1977). "The brain as a dream-state generator: An activation-synthesis hypothesis of the dream process". American Journal of Psychiatry 134 (12): 1335–1348.


Is it possible to memorize the sound of a certain pitch?

Yes, it seems like this ability can be acquired with practice.
In Identifying Notes without Perfect Pitch, the author picked twelve familiar songs, each of which started on one of the twelve pitches of the chromatic scale. Once he memorized the song-pitch association, he was able to recognize 10 out of of 12 pitches.
Some users of Music Stack Exchange mention similar results. For example, one person says they can remember the pitch of their tuning fork, and another suggests the song approach: "If hearing a note instantly reminds you of a song, then I think you are identifying that note, just by the song name, not the note name (that you may or may not happen to know)."


What are the reasons behind monogamy in humans?

First off, I think monogamy is a socially and culturally determined construct in man.

In the animal world both monogamy and polygamy are encountered. Monogamy increases the chance of the survival of individual offspring, as dad can help raising the offspring  and can defend the family. This increases fitness.

On the on the other hand, polygamy increases the spread of the (male) genes and hence increases the chance that the male gene pool is spread.

The relative benefits of both strategies depends on many factors, including resource availability, offspring need, parental care, and mating dynamics (Klug, 2018).

Reference
- Klug, Front Ecol Evol (2018); 2018.00030


Does deep, slow breathing increase mental performance?

I spent some time searching various databases with a variety of different keywords related to breathing techniques and mental outcomes. I only found a couple of studies that have looked at certain Yoga deep breathing techniques and their effects on cognitive tests measuring attention/concentration (Shirley Telles et al. 2007, 2013). Some of these specific techniques (such as selective or alternate nostril breathing) seemed to lead to better performance as compared to control groups (e.g., only breathing awareness).

I have to admit that I am a bit skeptical because the studies have small samples and placebo effects may have played a role.

In conclusion, there does not seem to be much research that would allow the strong and general claim the self-help book is making.

References

Shirley Telles, P. Raghuraj, Satyapriya Maharana, and H. R. Nagendra (2007) immediate effect of three yoga breathing techniques on performance on a letter-cancellation task. Perceptual and motor skills: volume 104, issue , pp. 1289-1296.

Shirley Telles, Arti Yadav, Ram Kumar Gupta, and Acharya Balkrishna (2013) Reaction Time Following Yoga Bellows-Type Breathing and Breath Awareness. Perceptual and Motor Skills: Volume 117, Issue , pp. 89-98.
doi: 10.2466/22.25.PMS.117x10z4


Are new memories stored in new neurons generated in the hippocampus?

Memories are generally understood to be encoded within networks of neurons, and not within neurons themselves. New neurons are certainly useful, but they are not necessary to store new memories.

Indeed, the hippocampus is extremely plastic, meaning that the connection strength between different neurons can change rapidly, and sometimes, new connections are also formed via the growth of new synapses (this is different than the addition of new neurons). However, "new" memories are often stored using different, overlapping subsets of neurons, which is commonly referred to as global remapping in the hippocampus.

Remapping comes from the notion that many pyramidal cells in the hippocampus show place-selectivity (so-called place cells) and many of the same neurons that encode one particular environment (e.g., your bedroom), would be recruited to encode an entirely different environment (e.g, your kitchen) with no apparent relationship between the two. That is, the subset of neurons recruited to encode a particular environment seems to be random, and the topology is not preserved: neurons that encoded adjacent regions in your bedroom might encode very distant regions in your kitchen, or no regions at all.

Short answer

Now to answer your question more clearly: the hippocampus is indeed critical for new memory formation; however, memories are not stored within individual neurons, but rather within collections of neurons (which could include both new and old neurons) and in the connection strengths of those neurons in particular. The same (new or old) neuron can be used and re-used in many memories, without disrupting the other memories that it forms part of.

Further information

A relatively accessible read (if you're so inclined) is Diekelmann, S., & Born, J. (2010). The memory function of sleep. Nature Reviews. Neuroscience, 11(2), 114–26. doi:10.1038/nrn2762, but it requires a paid subscription or institutional access. Alternatively, Scholarpedia has many good articles, including this one on the hippocampus, which goes a little further to explain part of our current understanding of how new memories are transferred (consolidated) to long-term storage in the neocortex.


Epigenetics and serotonin (amygdala threat response)?

From my limited understanding...

First off, you're definitely interpreting this correctly.  The authors note:

  […] methylation of the proximal promoter of human SLC6A4 predicts threat-related amygdala reactivity, possibly reflecting decreased serotonin transporter gene expression and, consequently, reduced regional serotonin reuptake.

However, it's definitely true that increased serotonin signaling is associated with increased amygdala reactivity (e.g., Fakra et al., 2009).

Moreover, SSRI administration in neurotic (Simplicio et al., 2013) and healthy (Bigos et al., 2008) adults seems to initially increase amydgala reactivity to threatening faces.  Simplicio et al. interpret this as facilitating "a process of decreasing emotional avoidance," which would be adaptive in the long-term through greater exposure (and habituation to) "benign 'threat' cues" like faces.

Both Fakra et al. (2009) and Bigos et al. (2008) suggest that acute effects of increased 5HT on amygdala reactivity may have to do with delayed effects on prefrontal cortex, which would otherwise exhibit control over amygdala reactivity. More specifically, Bigos et al. argue:

  While acute 5-HT reuptake blockade may potentiate stimulus-dependent amygdala reactivity, likely through stimulation of excitatory postsynaptic 5-HT receptors located on apical dendrites of glutamatergic neurons (McDonald and Mascagni, 2007), chronic blockade may lead to a more general increase in 5-HT neurotransmission via downregulation of negative feedback 5-HT autoreceptors (Blier and de Montigny, 1999). This shift toward generally increased neurotransmission after chronic reuptake blockade may allow 5-HT to potentiate the response of pyramidal neurons in prefrontal circuits, via volume transmission at excitatory 5-HT receptors localized extrasynaptically (Jansson et al, 2001; Sharp et al, 2007), thereby mediating top-down regulation of the amygdala (Hariri and Holmes, 2006).

So SSRIs might have long-term adaptive consequences via effects on prefrontal cortex, otherwise not seen acutely.


What is the relationship between neurotransmitter release and resting potential in retinal bipolar cells?

Bipolar cells reduce transmitter release when hyperpolarized, see the wikipedia page. When the bipolar cell is fully hyperpolarized it will basically stop releasing neurotransmitters. If transmitter release ever becomes totally zero I do not dare to say, however.


Word for naming your negative self-talk to overcome it

What you are talking about is the powerful technique of Compartmentalisation.  As highlighted in the Wikipedia link I provided here, normally speaking (emphasis mine)

  Compartmentalization is a subconscious psychological defense mechanism used to avoid cognitive dissonance, or the mental discomfort and anxiety caused by a person's having conflicting values, cognitions, emotions, beliefs, etc. within themselves.

  Compartmentalization allows these conflicting ideas to co-exist by inhibiting direct or explicit acknowledgement and interaction between separate compartmentalized self states (Leary & Tangney, 2011).

Carolin Showers (1992) described compartmentalisation as

  the tendency to organize positive and negative knowledge about the self into separate, uniformly valenced categories (self-aspects). As long as positive self-aspects are activated, access to negative information should be minimized.

however, you can consciously compartmentalise negative thoughts, feelings etc.

With regard to hypochondria in your question, compartmentalisation can be extremely difficult for hypochondriacs, as can they have trouble separating personal health facts from false perceptions of their personal health (see Illness Anxiety Disorder in DSM-5 (American Psychiatric Association, 2013) or Merck Manual, or ICD-10 code F45.21).

There are a lot of concepts directly and indirectly related to compartmentalisation, so that part of your question is too broad to answer fully here.  However as a start, you could look at secondary trauma (also called vicarious trauma).

Compartmentalisation is often employed, for example, by people within the emergency services (fire officers, paramedics, police officers, coastguard etc.) in order for them to concentrate on the immediate task whilst temporarily isolating themselves from their emotions. Problems can come later for these people if they do not deal with their compartmentalised emotions afterwards during debriefing or clinical supervision sessions.

When studying primary and secondary trauma in medical emergency personnel, Jane Shakespeare-Finch (2011) described this as

  adaptive compartmentalizing of emotion during a scenario in which focus on the patient is paramount.

References

American Psychiatric Association. (2013). Diagnostic and Statistical Manual of Mental Disorders. (5th Edition). Washington, DC.

Leary, M. R., & Tangney, J. P. (Eds.). (2011). Handbook of self and identity. Guilford Press.

Shakespeare-Finch, J. (2011). Primary and secondary trauma in emergency personnel. Traumatology, 17(4), 1-2.DOI: 10.1177/1534765611431834

Showers, C. (1992). Compartmentalization of positive and negative self-knowledge: Keeping bad apples out of the bunch. Journal of Personality and Social Psychology, 62(6), 1036-1049.DOI: 10.1037/0022-3514.62.6.1036


What causes student errors on a problem involving differentiating a factorial?

I imagine this question is tricky for students for a several reasons.

Question wording: The question may suggest to the student that it is possible to differentiate $x!$. Or they may assume from the wording that some meaning is meant where it is possible to differentiate. For example, alternatively, you could ask a set of questions, one for each functions, about whether a given function was differentiable (e.g., $x^2$, $2x+3x^3$, $log(x)$, $x!$). This would clearly be easier, because it puts the potential that the function might not be differentiable into the student's mind. I'm not saying what method of questioning is better from a pedagogy perspective; I'm just noting that question wording influences the difficulty of the problem, and that in this case, the question might be labelled a "trick question".
Analogy to solve novel problems: If students think that there is an actual derivative as an answer, but no obvious solution exists, it is natural to apply strategies that seem relevant to the problem. For example, they might know how to calculate $x!$ for any given positive discrete value of $x$. Therefore they might assume that working out the derivative involves interpolating (e.g., something like a gamma function) or they might rely on what they know about the product rule or some such. In general it is common for people to try to solve problems that they don't understand by drawing on strategies that seems relevant.
The question relies on the ability to apply a key fact that discrete functions are not differentiable. Thus, students need to know that fact, and they need to know that the factorial is a discrete function, and they need to link these two ideas. Thus, from a knowledge perspective, this question relies on a piece of knowledge that students might not possess.

So, in summary, I think the question exemplifies the kinds of challenges that students encounter when learning and demonstrating mathematical skills. I think a lot can be learnt about students cognitive representations of a problem by the kinds of errors they make. However, I do not think failing to solve this problem correctly says anything fundamental about your thinking style.

For further discussion of cognitive science in relation to mathematics education, perhaps check out Robert Siegler's work.

References

Siegler, R. S. (2003). Implications of cognitive science research for mathematics education. In Kilpatrick, J.,
Martin, W. B., & Schifter, D. E. (Eds.), A research companion to principles and standards for school. mathematics (pp. 219-233). Reston, VA: National Council of Teachers of Mathmatics.
PDF


The author responded. It is called "Subitising" or "Subitizing" or "Perceiving cardinality at-a-glance". The term was coined by Kaufman in 1949.


How to compute Chi-square value and degrees of freedom in Excel?

This is really more of a statistical question (except perhaps the bit about APA style). As such it probably belongs on stats.stackexchange.com .

A binary variable does not have a "normal distribution". A normal distribution is bell shaped and is relevant to continuous data.

Your null hypothesis is that the population proportions for left and right handers are equal. Thus, if your chi-square value is sufficiently large, then you might reject the null hypothesis and conclude that the population proportions are unequal.

If $k$ is the number of categories (you have two categories), then
degrees of freedom for the one sample chi-square test is $k-1$ (i.e., $2-1 = 1$).

To calculate chi-square check out the example here.

The following formula in Excel should give you a p-value. For example if your chi-square value was 22, and your degrees of freedom was 3:

 =1-CHISQ.DIST(22, 3,TRUE)

the first argument is the chi-square value
The second argument is the degrees of freedom
The third argument indicates that a cumulative distribution (CDF) is desired
Thus by taking 1 minus the value of the CDF you get the probability of getting a chi-square value as large or larger than the observed value.

You can check your formula by looking at existing calculated tables.
http://home.comcast.net/~sharov/PopEcol/tables/chisq.html


Is remembering a list of words an example of semantic or episodic memory?

The definitive categorization of memory is an example of semantics (an irony I enjoy in answering this question).
Firstly, you have asked four questions in one.

So which one is it?

Definition of semantic:

adjective
relating to meaning in language or logic.

Semantic is the imposed meaning that human beings give things.
Remembering a list of words, would be semantic memory, as the person is required to recollect a list, that has been arbitrarily compiled, as opposed to recalling the experience of reading the words.

Are there any large disagreements within the community of what episodic memory actually is?

Not that I am aware of, but I am not an expert and have not investigated this thoroughly.

Are word list tests seen as something that at least captures a small part of episodic memory?

Word list test would be capturing semantic memory, though I doubt they would form long term memory, as they are only being held for a short period of time, have no emotional context, nor form the part of pattern or logic of any semantic learning. Taking and remembering the test itself would form episodic memory, in recalling the event, time and place, with, the long term semantic memory in knowing how to do such a test. I have addressed this in more detail under the next point.

If remembering a list of words isn't an example of episodic memory, then what is it an example of?

To answer this, I am going to present two alternative arguments.
As episodic memory.
To   regard  it as episodic memory, (but short term memory, which is muddying the waters, as the information only needs to be keep in the memory for a short term and would be used within the working memory) so in terms of it being episodic, it is unlikely to be recalled effectively at a later date (for most people). I would liken it to being shown images of animals, with no  purpose of pattern, except the person is asked to retain a memory of what they have seen. Like going to a museum and then being asked, what did you see there, as opposed to going to a museum and then being asked what was the history of the steam engine, which would be recalled from semantic memory of reading about the team engine at the museum.
In this context, a test of semantic memory would be to give the individual the rules of a new game and ask them to memorise them. If a person was being asked to remember the periodic table of elements, this would be semantic memory, as it would be something the person would later use as a useful pool of human defined information, like the rules of a card game.
As Semantic memory
So in terms of the concept of semantic memory being the recall of facts, as opposed to episodic memory being the recall of personal facts, it could be argued that recalling a list is using semantic memory. The list is a generic and semantic thing (human created rules, as opposed to the spontaneous and authenticity of life experience, that creates episodic memory). So regardless of the intention, it is a semantic list, that has no bearing on action or what is occurring, hence the episodic memory. The episodic memory, may be of perspiring whilst trying to recall 20 unrelated words. So the person is trying to jam 20 words into their short term memory, in a rote learning fashion. Rote memory would be regarded as semantic memory.

Rote Memory (item or semantic memory)  (1)

Episodic memory could be considered explicit memory, whereas semantic memory could be considered implicit memory, as it does not require the recall of a particular event, but it the memory of a generic mental exercise, as opposed to the test itself.
The ability to use a pen and write out the test form, is an example of implicit procedural memory, the memory of a teacher leaning over you and showing you how to write is an example of explicit, declarative, episodic memory. Knowing how the testing process works is an example of implicit, declarative, semantic memory.

Semantic and episodic memory are related, both being  types of declarative memory.

Types of Memory
Declarative vs. Procedural Memory
Declarative memory is recall of factual information such as dates, words, faces, events, and concepts. Remembering the capital of France, the rules for playing football, and what happened in the last game of the World Series involves declarative memory. Declarative memory is usually considered to be explicit because it involves conscious, intentional remembering.
Semantic vs. Episodic Memory
Declarative memory is of two types: semantic and episodic. Semantic memory is recall of general facts, while episodic memory is recall of personal facts. Remembering the capital of France and the rules for playing football uses semantic memory. Remembering what happened in the last game of the World Series uses episodic

Episodic memory is the memory of autobiographical events (times, places, associated emotions, and other contextual knowledge) that can be explicitly stated. It is the collection of past personal experiences that occurred at a particular time and place. For example, if you remember the party on your 6th birthday, this is an episodic memory. They allow you to figuratively travel back in time to remember the event that took place at that particular time and place.
Tulving has seminally defined three key properties of episodic memory recollection. These are: a subjective sense of time (or mental time travel), connection to the self, and autonoetic consciousness. Autonoetic consciousness refers to a special kind of consciousness that accompanies the act of remembering which enables an individual to be aware of the self in a subjective time. Aside from Tulving, others named the important aspects of recollection which includes visual imagery, narrative structure, retrieval of semantic information and the feelings of familiarity.

Semantic memory refers to the memory of meanings, understandings, and other concept-based knowledge, and underlies the conscious recollection of factual information and general knowledge about the world. Semantic and episodic memory together make up the category of declarative memory, which is one of the two major divisions in memory. With the use of our semantic memory we can give meaning to otherwise meaningless words and sentences. We can learn about new concepts by applying our knowledge learned from things in the past. The counterpart to declarative, or explicit memory, is procedural memory, or implicit memory.
Semantic memory includes generalized knowledge that does not involve memory of a specific event. For instance, semantic memory is knowing how to add and subtract, whereas episodic memory is the specific memory of being taught how to subtract.

Disclaimer: I could be completely wrong.

Reference:
(1) BRAIN Research Compatible Memory Strategies Judy Willis, M.D., M.Ed.


Do people with ADD or Asperger's Syndrome often show different learning curves than neurotypical individuals?

Although I don't know any publications exactly on that matter it is possible to be true.
So please treat this as a speculation.

People with Asperger Syndrome (or High-Functioning Autism) have higher attention to detail and tend to build more rigid structures in their minds (while neurotypicals may have more error-tolerant but less efficient structures). So it is very possible that the learning curve for AS starts slowly and then have sharp leaps. In the initial stage they may see merely a collection of facts (while neurotypicals can manage to work with them as they are less demanding when it comes to the self-consistency and structure). However, when it 'clicks' and one understands pattern of the structure it may give a considerable advantage.

Moreover, it may be also about time spent learning. Once a person with AS feels safe in a topic, (s)he may like to learn it even, while for a neurotypical there is no so much fun in learning more details.

When it comes to the relation of skills and cognitive style and Asperger Syndorme, the following references may be useful:

Samuel J. Umland, Karl Wessel "Cassandra Among the Cyborgs" in Darren Tofts Prefiguring Cyberculture: An Intellectual History
Hsu-Min Chiang, Yueh-Hsien Lin, Mathematical ability of students with Asperger syndrome and high-functioning autism: A review of literature (2007)

The first one is an essay relating cognitive styles of: people with AS, nerds and science. The second shows that there is high variance in mathematical skills among people with AS (so most are below average, but some are way above).

From my experience, the effect is very well visible when it comes to presenting knowledge. Nerdy people typically are bad at presenting topics they don't understand well. Neurotypical do it much better (perhaps because they make 'didactic lies' much easier, or they are not concerned so much by 'chaos' or lack of self-consistency, or they are better at repeating catch-phrases). At the same time nerds understanding a topic well often understand it really well (knowing a lot of connection, analogies, what is exact and what approximate, etc).


Why does the human visual system produce a bright patch after staring at a bright light source and looking away?

The persistence that you observe when you look at a bright light for a short period of time is called flash blindness. The phenomenon is related to your retina's response to the burst of light. Quoting from the Wikipedia article:

  Flash blindness is caused by bleaching (oversaturation) of the retinal pigment. As the pigment returns to normal, so too does sight. In daylight the eye's pupil constricts, thus reducing the amount of light entering after a flash. At night, the dark-adapted pupil is wide open so flash blindness has a greater effect and lasts longer.


How important is eye contact for hypnotism?

There are different kinds of hypnosis. In therapeutic settings traditional, or classic, hypnosis is differentiated from modern, Ericksonian hypnosis.

Traditional hypnosis, as it has been used from Mesmer to Freud, is based on direct commands. The hypnotist usually acts in a dominant manner and uses eye contact, pendulums, fixation of the index finger etc. to induce the trance. Advantages of traditional hypnosis are quick induction of trance and often a quick deepening of trance. Disadvantages are that not everybody is susceptible to this kind of hypnosis. Show hypnotists use traditional hypnosis, but they preselect their subjects to work with those susceptible to direct commands. Direct induction is also popular in the context of NLP.

James Braid explains the eye fixation method of trance induction in Neurypnology (1843):

  Take any bright object (I generally use my lancet case) between the
  thumb and fore and middle fingers of the left hand; hold it from about
  eight to fifteen inches from the eyes, at such position above the
  forehead as may be necessary to produce the greatest possible strain
  upon the eyes and eyelids, and enable the patient to maintain a steady
  fixed stare at the object.

  The patient must be made to understand that he is to keep the eyes
  steadily fixed on the object, and the mind riveted on the idea of that
  one object. (p. 27)

James Braid inducing a trance with the eye fixation method

Ambroise-Auguste Liébeault, founder of the Nancy school of hypnosis in the 19th century (distinguished from the Paris school around Charcot at the Salpêtrière), used eye contact to induce a hypnotic trance in his patients. (Kossak, 2004, Hypnose: Lehrbuch für Psychotherapeuten und Ärzte, Weinheim: Beltz, p. 22)

Modern or Ericksonian hypnosis, developed during the 20th century, mainly by Milton H. Erickson, does not use any auxiliary means. Trance is induced indirectly during conversation. The client falls into trance slowly and without noticing. Advantages are a pleasant feeling during trance and a better acceptance than during traditional hynosis. Also, a dialogue with the unconscious is easier in modern hypnosis. A disadvantage is that the trance is usually not very deep (usually a medium depth).

Therapists often use a combination of both methods to utilize the advantages of both methods.

To answer your question, while eye contact is unnecessary – Milton H. Erickson, in Hypnotic Realities, says that "often the therapist does not even look at the patient's face" –, it is one of several methods for inducing quick and deep trances in suitable subjects.

I don't know that there is an "optimal eye locking duration", as the time to fall into trance – and thus the time of fixation, if the eye fixation method is used – varies with the "hypnotizability" of the subject. James Braid (Neurypnology, 1943, p. 27) describes that "[a]fter ten or fifteen seconds have elapsed, by gently elevating the arms and legs, it will be found that the patient has a disposition to retain them in the situation in which they have been placed, if he is intensely affected", but then continues to describe how to proceed if the subject has not fallen into a trance after that period of time.


Folding (wrinkles) in cortex: Why is surface area more important than volume?

The key point is that the brain is not a uniform structure. The outer layer, known as grey matter, is a relatively uniform and flat structure. Underneath the grey matter is white matter. An overly-simple characterization of these two areas is that grey matter performs computations, and white matter lets different areas of grey matter talk to each other. Here's an image of a dissected brain from wikipedia where you can clearly see the ring of grey matter.

One reason for the folds might be that if you want to fit a flat structure (like grey matter) into a tight space, folding it is one way to fit more of it. Another aspect of this is that the folds bring different areas of grey matter closer together, which means less white matter is needed to connect the areas together.