Ligand-gated ion channels as operators Isn't there a perfect analogy between ligand-gated and voltage-gated ion channels considered (mathematically) as (non-linear) operators, mapping one function (of time) to another one? Voltage-gated channels respond to voltage signals (= functions of time at a given location, not just a voltage), ligand-gated channels respond to neurotransmitter signals (not just neurotransmitters). Both yield a conductance profile (as a function of time, not just a conductance).

Both ligand- and voltage-gated ion channels display some form of hysteresis, i.e. the dependence of the state of a system on its history. Hysteresis can not be modelled by simple mathematical functions (by which dependencies normally are modelled), but maybe better by some non-linear operators.

With respect to the Hodgkin-Huxley model (that AliceD mentions in her answer): In this model (that is also used by Rall) the resistances (= ion channels) are just switched on and off instantaneously. But this may be oversimplified: it takes some time, and it cannot be done with arbitrary frequency. That's why we possibly need operators to describe them.

My question is: Are there references where ligand-gated channels are modelled mathematically as (non-linear) operators?

Short answer
Generally, Hodgkin & Huxley-derived models are used to describe the gating characteristics of ion channels and ligand operated receptors.

Background
Ligand-gated and voltage-operated ion channels do not really perform a memory task. Instead, they channel ions across the cell memnrane and by doing so they can convey information from out the cell (neurotransmitter release / voltage changes) into the cell. Their role is physiological and the way they are modeled is typically based on Hodgkin & Huxley kinetics (Sig, 2014) (Fig. 1).

Fig. 1. Hodgkin & Huxley model of membrane kinetics. source: Neuronal Dynamics

The Hodgkin-Huxley model models the semi-permeable cell membrane as a capacitor that separates the interior of the cell from the extracellular fluid. If an input current is injected into the cell, it may add further charge on the capacitor, or leak through the channels in the cell membrane. Each channel type is modeled by a resistor (conductor of current). The unspecific channel has a leak resistance R, the sodium channel a resistance RNa and the potassium channel a resistance RK. The diagonal arrow across the diagram of the resistor indicates that the value of the resistance is not fixed, but changes depending on whether the ion channel is open or closed. Because of active ion transport through the cell membrane, the ion concentration inside the cell is different from that in the extracellular liquid. The Nernst potential generated by the difference in ion concentration is represented by a battery. The Nernst potential depends on the ion and hence there are separate batteries for sodium, potassium, and the unspecific third channel, with battery voltages ENa, EK and EL (source: Neuronal Dynamics).

Now to your edited question: you say

  [Ion channels] are just switched on and off instantaneously. But this may be oversimplified: it takes some time...

It goes further than that; voltage-operated ion channels like the Na+ channel are actively activated and inactivated with well-defined time constants that, among other things, govern the process of absolute and relative refractoriness of nerve cells (Fig. 2). The temporal gating characteristics in terms of activation and inactivation are expressed as time constants, which can be described in for example a Markov model (Wang et al., 2004). For example,

dm/dt = 1/τm(V) * (m∞(V)−m), where

m∞(V) = α(V) / [α(V)+β(V)] (9)
τm(V) = 1 / [α(V)+β(V)]

Here, m∞ is the steady-state activation and τm is the activation time constant of the Na+ current (n∞ and τn represent the same quantities for the K+ current). In the case of h, h∞ and τh are called steady-state inactivation and inactivation time constant, respectively (source: Destexhe & Huguenard, 2007).

Similar formulas apply to the association and dissociation constants in ligand-operated channels, where timing of activation and inactivation are affected by the ligand's affinity for the receptor.

Fig. 2. Ion channel gating. source: Lehmann-Horne & Jurkatt-Rott (1999)

References
- Lehmann-Horne & Jurkatt-Rott, Physiol Rev (1999); 79(4): 1317-72
- Sig, J Gen Physiol (2014); 144(1) 7-26
- Wang et al., J Physiol (2004); 557(3): 705–17


Freeware for measuring keystroke duration I am searching for freeware to measure the duration of a keystroke or mouse-click, both would work. Does anyone have an idea?

Matlab toolboxes are, unfortunately, of no use to me.

Psychopy (http://psychopy.org) can do this. It can do it in two ways.

Using iohub. Iohub is a crazy powerful way to get any information about any kind of input to your system, from keyboard, mouse, eye-trackers, etc. You can see the documentation for keyboard here.

from psychopy.iohub import launchHubServer
io = launchHubServer()
keyboard = io.devices.keyboard  # handy name

print 'start pressing a key now'
key_info = keyboard.waitForReleases()[0]  # Just grab first release, even if there are multiple
print 'Press time was', key_info.duration
print '... and BTW, all key event info was', key_info

Using pyglet:

from psychopy import visual, event, core
win = visual.Window()  # Disadvantage: you need to have a window open to record it.
clock = core.Clock()

# Start listening
print 'start pressing a key now'
key, time = event.waitKeys(timeStamped=True)[0]
clock.reset()  # Key down time
while event.getKeys():
    pass
print 'key lasted', clock.getTime(), 'seconds'

If measuring key strokes is the only thing you need, psychopy may be a bit heavy since it is meant for running full experiments, but it will do the job!


I am looking for the name of a phenomenon where people blindly follow others when they sense a threat So I am composing a post and I am looking for a name of the behaviour among people that they start running when they see two or more people running in opposite direction sensing a potential threat or when two or more people are looking upwards, others also start looking upwards. Such phenomena is recorded in various funny videos compilations and I would like to know if there is any name of such phenomena or any description of such phenomena that I can refer to in the post?

Herd mentality (aka mob mentality) involves people following others without (deliberate) thinking - ie, impulsively or blindly:

  ... describes how people can be influenced by their peers to adopt
  certain behaviors on a largely emotional, rather than rational, basis.

Most experiments in herd mentality involve strangers.  There are other terms for non-impulsive behaviors (Wikipedia lists group intelligence, crowd wisdom, groupthink, deindividuation, and decentralized decision making).

That is contrasted with swarm behavior.  Herd mentality usually refers to individuals conforming to or blindly following others, whereas swarm behavior does not involve individuals doing the same thing:

  ... it is an emergent behaviour arising from simple rules that are
  followed by individuals and does not involve any central coordination.

Rather, in swarm behavior, individuals make different decisions depending on what others around them are doing, such as avoiding predators based on the reactions of others.  Confusingly, "herding" is swarm behavior (in insects it's called swarming; but fish school, birds flock, and mammals herd).


Does associative recognition retrieve target when given re-paired foil? Context

In "Tracking cognitive processing stages with MEG: A spatio-temporal model
of associative recognition in the brain" by Borst et. al., MEG is used to show the existence of discrete stages during the test-phase of an associative recognition task, as shown in the figure below:

Question

In the step labeled "Recollection", does an input of a Re-Paired Foil word pair cause the recollection of a Target?

Explanation of task

During the study phase, a set of paired words are given. Such as (A+B, C+D, E+F). During the test phase, the subject must distinguish whether they have seen a pair before. A pair that has previously been studied, such as A+B, is referred to as a Target. Pairs that have not previously been studied, such as B+F and A+Z are called Foils. A+Z is a Novel Foil because it is composed of a word was not studied, while B+F is a Re-Paired Foil because it is composed of words seen during the study phase.

What is being described in the original question is called Recall-to-Reject Processing. In "Associative recognition: a case of recall-to-reject processing" by Rotello and Heit provides evidence this retrieval of an older memory for comparison with the newer probe, rather than retrieving nothing, does indeed happen.

To show this, they ran three experiments. Experiment 1 dealt with word pairs similarly to the experiment cited in the original post. Experiment 2 test on both word pairs and individual pairs.

The results of Experiment 1 show accuracy was higher for newer pairs than for re-arranged pairs. Consequently, one can infer that Recall-to-Reject had a harder time with re-arranged pairs due to interference [1]. The same occurred in Experiment 2, but additionally showing interference with words similar to those studied.

They summarize the result in their conclusion:

  [Recall-to-Reject Processing] makes a distinctive prediction about the ability of subjects to discriminate completely new test stimuli from stimuli that are new but similar to studied materials. Specifically, the similar test foils should be increasingly rejected, relative to a baseline of completely new items, late in processing (i.e., after information from the recall component of recognition becomes available). The data from Experiments 1 and 2 are consistent with that prediction: We did find that rearranged pairs were increasingly rejected, relative to new pairs, after about 1,000 msec.

However, it should be noted this is quite an old paper and an updated reference would be helpful.

[1] There's also some sort of trend happening with lags, but this isn't really necessary to understand for this answer.


Encouraging Kindness in Rich People? Evidence presented in this video suggests that, statistically, rich people are more likely to be jerks than people with less money. How could this tendency be curbed, especially with regards to rich kids?

This is an interesting question as it has been of the opinion of many people around me that people who drive certain cars or are in a particular job or social status are selfish and don't care about anyone but themselves and maybe a little about those in their own circle of people.  But is this true?

TLDR - It seems to be true from studies presented, however there may be exceptions

For context, we need to define 'jerks' and 'rich' within the studies and the YouTube video you linked to (AppSCIENCE, 2018) had the studies and reports linked to it — NPR (2018), Piff, et al. (2012), Roberts & Zarracina (2015) plus others — which backed their claims.

Rich (Definition)

Roberts & Zarracina (2015) linked to the YouTube video talks of rich people being those who are

  at or near "the 1%" in wealth with an average income of $1M per year or more

some others would define it as someone who is substantially more financially well off and can include some below the top 1%.  My answer is based on this definition (see Social class, or socioeconomic status (SES) below).

Jerk (Definition)

The Oxford Living Dictionary defines Jerk as:

  A contemptibly foolish person

whilst the Urban Dictionary says

  Jerks are selfish, manipulative bas****ds

but Piff, et al. (2012) linked to with the YouTube video talked about:

  how social class is associated with unethical behavior, or actions that harm others and are illegal or morally objectionable to one's community

with Social class, or socioeconomic status (SES) being:

  an individual's rank vis-à-vis others in society in terms of wealth, occupational prestige, and education (Adler et al. 2000)(Kraus, Piff, & Keltner, 2011)

and there is a MacArthur scale of subjective SES which was used by Piff et al. (2012).

The evidence

Piff, et al. (2012) conducted 7 studies for their report

  In studies 1 and 2, upper-class individuals were more likely to break the law while driving, relative to lower-class individuals. In follow-up laboratory studies, upper-class individuals were more likely to exhibit unethical decision-making tendencies (study 3), take valued goods from others (study 4), lie in a negotiation (study 5), cheat to increase their chances of winning a prize (study 6), and endorse unethical behavior at work (study 7) than were lower-class individuals.

Roberts & Zarracina (2015) covered the Washington Post story about water restrictions imposed in the wake of California's drought, and how wealthy people were reacting to them, along with research by Gillens & Page (2014) and Page, Bartels, & Seawright (2013) which were studying the political viewpoints of the elite.

The Washington Post story quoted a wealthy Californian resident to have said:

  I think we’re being overly penalized, and we’re certainly being overly scrutinized by the world," said Gay Butler, an interior designer out for a trail ride on her show horse, Bear. She said her water bill averages about $800 a month.

  It angers me because people aren’t looking at the overall picture," Butler said. "What are we supposed to do, just have dirt around our house on four acres?"

when talking about the fact that everyone had the same limit on water usage.  Defending the amount of water she and her neighbors "need" for their vast estates she also said:

  You could put 20 houses on my property, and they’d have families of at least four. In my house, there is only two of us,” Butler said. So “they’d be using a hell of a lot more water than we’re using.

Possible exceptions

On the other side of the spectrum, Rancho Santa Fe resident Randy Woods was feeling burdened by his lush landscape and opted to downsize. The 60-something chief executive of a biotech company moved a year ago from a two-acre estate — replete with two waterfalls, two Jacuzzis, a swimming pool and an orchard — to a condo in the tiny core of town known as “the Village.”

Woods said some of his friends would like to do the same, largely to cut down on their bloated water bills. But they have encountered an unforeseen obstacle, he said: The drought has dampened demand for large estates in San Diego County.  Another friend, Woods said, has seen the value of his nine-acre plot plummet from 30 million US Dollars to 22 million US Dollars.

So my question with those who are choosing not to sell because of drops in property value is, is this greed at play?  You could say that when you can still get $22M and therefore still live comfortably; plus Piff et al. (2012) states:

  Mediator and moderator data demonstrated that upper-class individuals’ unethical tendencies are accounted for, in part, by their more favorable attitudes toward greed.

Piff, et al. (2012) also highlights:

  significant philanthropy displayed by such individuals as Bill Gates and Warren Buffet

but the cynics would say that these people are motivated purely by self-interest rather than acting for honourable or unselfish reasons.  (They are doing it to look good and say "look at how thoughtful I am").

There are also likely to be instances of lower-class individuals exhibiting unethical tendencies, as research on the relationship between concentrations of poverty and violent crime indicates (Sampson, Raudenbush, & Earls, 1997).

References

Adler, N. E., Epel, E. S., Castellazzo, G., & Ickovics, J. R. (2000). Relationship of subjective and objective social status with psychological and physiological functioning: Preliminary data in healthy, White women. Health psychology, 19(6), 586.DOI: 10.1037/0278-6133.19.6.586

AppSCIENCE (2018). Are Rich People Worse Humans? (YouTube Video)Available at: https://www.youtube.com/watch?v=L90R6PtxFKE

Gilens, M., & Page, B. I. (2014). Testing theories of American politics: Elites, interest groups, and average citizens. Perspectives on politics, 12(3), 564-581.DOI: 10.1017/S1537592714001595

Kraus, M. W., Piff, P. K., & Keltner, D. (2011). Social class as culture: The convergence of resources and rank in the social realm. Current directions in psychological science, 20(4), 246-250.DOI: 10.1177/0963721411414654

NPR (2018). The Power Hour - Hidden Brain: A Conversation About Life's Unseen Patterns (Podcast)Available at: https://www.npr.org/2018/01/23/579976635/the-power-hour

Page, B. I., Bartels, L. M., & Seawright, J. (2013). Democracy and the policy preferences of wealthy Americans. Perspectives on Politics, 11(1), 51-73.DOI: 10.1017/S153759271200360XFree PDF from: James N. Druckman, Department of Political Science, Northwestern University

Piff, P. K., Stancato, D. M., Côté, S., Mendoza-Denton, R., & Keltner, D. (2012). Higher social class predicts increased unethical behavior. Proceedings of the National Academy of Sciences, 109(11), 4086-4091.DOI: 10.1073/pnas.1118373109

Roberts, D. & Zarracina, J. (2015). Rich people are jerks, explained VoxAvailable at: https://www.vox.com/2015/6/16/8790357/rich-people-jerks

Sampson, R. J., Raudenbush, S. W., & Earls, F. (1997). Neighborhoods and violent crime: A multilevel study of collective efficacy. Science, 277(5328), 918-924.DOI: 10.1126/science.277.5328.918


How does a female measure her own attractiveness? In theory, a female who is above average should reject most advances because they can afford to wait until they are approached by a male of high value. Whereas a female of low attractiveness can not afford to reject most advances.

But how does a female gauge here own attractiveness in the first place?

What would make sense is that in the fist few years of adult life a female should simply reject all advances. A process of simply collecting statistical data on her own attractiveness.

Then females who are approached at a low level during this period would become more easily approachable whereas females who are approached at a high level would become more stand-offish.

Does any of this correspond to reality?

From p. 207 of Geoffrey Miller (2001). The mating mind: how sexual choice shaped the evolution of human nature. Anchor Books. ISBN 0-385-49517-X

  In our research on mate search strategies, colleague Peter
  Todd and I found that a rule we call "Try a Dozen" performs as
  well as the 37 percent rule under a wide range of conditions. Try
  a Dozen is simple: interview a dozen possible mates, remember
  the best of them, and then pick the very next prospect who is
  even more attractive. You do not have to estimate the total
  number of potential mates you will encounter in your
  reproductive lifetime; you only have to bet that you will meet at
  least fifty or so. Humans seem to follow something like the Try a
  Dozen rule: we get to know a number of opposite-sex friends
  during adolescence, fall in love at least once, remember that
  loved one very clearly, and tend to marry the next person who
  seems even more attractive. Each individual is "satisficing"-
  looking for someone who is pretty good and good enough, rather
  than the absolute best they could possibly find. But at the
  evolutionary level, these satisficing rules impose sexual selection
  that is almost as strong as the most complicated, perfectionist
  decision strategy.

I also turned up a 1998 review by Miller and Todd "Mate Choice Turn Cognitive", which does get to mating strategies in its final pages, best summarized by:

  By sampling a much smaller number of
  prospects initially, say a dozen, one can actually attain a
  higher expected mate value than the 37% rule delivers (although
  a lower chance of finding the very highest-valued
  prospect), with much lower search costs and a much lower
  risk of being stuck with a low-value mate[64,65] (Fig. 3).
  More importantly, the ‘secretary problem’ ignores the
  problem that a prospect you desire may reject you. This
  mutual choice constraint makes the search much harder[64,65].
  Game-theory models of ‘two-sided matching’ address these
  complexities[61] directly, and propose various search strategies
  which guarantee that a population reaches a ‘stable matching’:
  a pairwise assortment of individuals where no individual
  would prefer to be mated with someone else who would also
  prefer to be mated with them. However, two-sided matching
  models typically assume strict monogamy (no ‘extra-pair
  copulations’), complete information and exhaustive preferences:
  everyone has complete, consistent, transitive
  preferences across all possible prospects that they encounter.

  Roth, A.E. and Sotomayor, M.A.O. (1990) Two-sided Matching: a Study
  in Game-theoretic Modeling and Analysis, Cambridge University Press

  Todd, P.M. (1997) Searching for the next best mate, in Simulating
  Social Phenomena (Conte, R., Hegselmann, R. and Terna, P., eds),
  pp. 419–436, Springer-Verlag

  Todd, P.M. and Miller, G.F. Heuristics for mate search, in Simple
  Heuristics that Make us Smart (Gigerenzer, G., Todd, P.M. and the ABC
  Research Group), Oxford University Press (in press)

So yeah, the problem is not that simple (as optimal stopping) if one considers mating a game (in the sense of game theory). I haven't yet looked at the latter line of research... but it's a whole book. The idea seems centered on the stable marriage problem. An optimal algorithm also involves a number of rounds, with rejection and "maybe" answers; from Wikipedia:

  In the first round, first a) each unengaged man proposes to the woman he prefers most, and then b) each woman replies "maybe" to her suitor she most prefers and "no" to all other suitors. She is then provisionally "engaged" to the suitor she most prefers so far, and that suitor is likewise provisionally engaged to her.
  In each subsequent round, first a) each unengaged man proposes to the most-preferred woman to whom he has not yet proposed (regardless of whether the woman is already engaged), and then b) each woman replies "maybe" if she is currently not engaged or if she prefers this guy over her current provisional partner (in this case, she rejects her current provisional partner who becomes unengaged). The provisional nature of engagements preserves the right of an already-engaged woman to "trade up" (and, in the process, to "jilt" her until-then partner).
  This process is repeated until everyone is engaged.

So, Miller and Todd cleary don't think this stable marriage problem is too relevant for reality. Unfortunately, by the time of their review (which is now two decades old), there's wasn't much else proposed that was taking into account the mutual-choice aspect of mating and the "satisficing" nature of human choice in general (that Miller and Todd favor).


Variables in positive reinforcement in human beings I've been thinking about positive reinforcement occasionally, and I've always found myself wondering about various things that can influence it.

So, I'm looking for information (results of empirical studies) about the variables affecting positive reinforcement, in hopes of finding answers to my questions and questions that I haven't even thought of, such as:

How does knowing what the positive stimulus is for affect the change? What happens if I did two things, and I don't know which one of them led to the positive stimulus? e.g. I solved a math problem and won some game, and then I received a prize, and I don't know for which one of these things

What happens If (as far as I'm concerned) I did nothing, and then I receive a prize?

If I receive a prize for something I did an hour earlier, for example, will it still change my behavior?
Does receiving a prize while I do a task has a stronger effect? weaker?

Any other interesting questions (as well as answers to them) are welcome

(And since someone is probably going to make a few changes and add tags - thank you and forgive me. English is not my native language, and I don't have much of a background in psychology)

Your question is, in essence, a request for a mathematical model of Temporal Difference Reinforcement Learning.  In a nutshell, temporal difference models add a notion of time to reinforcement learning models, which describe reinforcement learning as a comparison between what was expected and what actually occurred.

I think most of your answers can be found in the article above.  =)

Edit re: my insistence on mathematical models providing the answer to your question:

Just to be clear, mathematical models don't exist in a vaccuum.  Good models are:

built from constraints imposed by experimental observation
tractable; that is, they reflect the (presumed) underlying implementation

Case and point, the Rescorla-Wagner model's1 delta (prediction error) parameter has been correlated to the phasic activity of dopaminergic neurons.  This is precisely why the model is so hugely successful; it describes not only the experimental data, but the apparent neurological underpinnings, at least superficially.

Note that this is a very important kind of validity for neurological models, so much so, in fact, that there is an entire class of neuroimaging papers dedicated to finding functional activations that correspond to various parameters in such high-quality models.  Exhibit B.

I think your confusion arises from a lack of familiarity with the modelling approach to cognitive neuroscience (and that's okay! It's not obvious!), as well as a non-trivial distinction between the questions "what happens", "how does it happen" and "where does it happen".  You specifically asked what happens, which is the realm of formal mathematics.  What happens, as best we can tell, is that learning is driven by updating a prediction about what will happen concomitantly with (or shortly after) a stimulus, with what actually happens when that stimulus is sensed.  The models describe the exact nature of this interaction.  If you want to be more specific than this, you need to dive into the math.  If you want to know where or how these computations are performed, then that's another question entirely.

1.  this model doesn't integrate any notion of time, contrary to the above TDRL model


Are we biased against other people's suggestions? Recently, I have realized that whenever my friends suggest me a movie or a tv show to watch, there is an instinctive response inside me that always tells me to not try the suggestion. I then realized that this is also true when it comes to books and music. I later told my friend this and he told me that he always has the same reaction whenever I suggest something to him. I do not think lowly of his opinions in any way and our taste has many things in common. The same thing goes for him.
Interestingly, even after we have acknowledged this reaction, it is still present whenever a suggestion is raised by either one of us.
My only guess is a sense of pride over what I like but I am not too sure. I was just wondering whether it is a common phenomenon where we are instinctively biased against others' suggestions in clearly subjected matters such as movies, books, or music genres or not. If yes, then what are the ways to minimize this reaction?

It can be caused by reactance - automatic opposite response preventing actions that threatens behavioral freedom. You can find more about reactance in:
Baron, Robert A.; et al. (2006). Social Psychology. Pearson. ISBN 9780205444120.
Roeckelein, J. E., ed. (2006). "Reactance theory". Elsevier's Dictionary of Psychological Theories. Elsevier. pp. 507–508. ISBN 9780080460642.


What is actually going on in your brain during a night terror? I used to have really bad night terrors back in the day, where I would think I was floating and I would wake up and actually my vision would be very fuzzy - so I just want to know..

What is actually going on in your brain during a night terror? Is there any evidence that the type of bed one sleeps on makes any difference in lowering the incidence of night terrors?

Night terrors, a type of parasomnia has been the subject of considerable study.

According to "Insights from studying human sleep
disorders" (Mahowald and Schenck, 2005), parasomnias are in two categories:

  The common parasomnias are another example of
  ‘dissociated sleep states’, representing the simultaneous admixture of
  wakefulness and either NREM sleep (disorders of arousal such as
  sleepwalking or sleep terrors) or wakefulness and REM sleep (REM
  sleep behaviour disorder). Parasomnias may result in striking clinical
  phenomena, which appear as the brain becomes reorganized across
  states, and are therefore apt to occur during the transition from one
  state to another.

Sleep terrors are an example of NREM sleep disorder and are usually the result of febrile illness, sleep deprivation, physical activity, emotional stress and medications - so the question about the bed can relate, particularly if the bed is causing lack of sleep.


What is a effective and interactive exercise to demonstrate cognition to a class I'm new to this site so I may mess up here and there with the question process.

I need to come up with an interactive exercise for a class to demonstrate cognition. The problem is, I find cognition to be very complex and I have trouble thinking of one.

Some ideas I currently have in mind are:

1) Telling the class some false facts or showing them some fake news and having them debate which is real.

2) Something along the lines of a slot machine where extravagant sounds and lights play when you win something, however, nothing happens when you lose. Showing how we are more likely to remember the extravagant sounds/lights.

3) Asking the class to describe to me an object. Then ask the class to describe the same object to me without the use of certain words and concepts.

I am very clueless on this matter (cognition) so any help would be appreciated.

I would recommend something like the Invisible Gorilla! This is a classic demonstration from Simons & Chabris (1999) that demonstrates the selectivity of attention. Demonstrating "cognition" is a bit broad, but this is a famous example of the ways in which cognitive processes select, omit, and process information.

Video of the illusion (with instructions) here: https://www.youtube.com/watch?v=vJG698U2Mvo&feature=youtu.be

NPR story discussing the experiment/illusion in simple terms: https://www.npr.org/templates/story/story.php?storyId=126977945


Does short-term memory decrease after working memory, or does it decrease before working memory? I see contradicting claims.

This book shows working memory peaking in 20s, short term memory peaking out later (not doing badly until one's 40s), but this paper shows STM peaking out earlier than working memory.

It doesn't really make sense to talk about whether "short-term memory" or "working memory" decline first, so I think there is some confusion of terminology. It seems the reference comes from the second linked article, which colloquially suggests that 'short-term' face memory declines before working memory. In modern working memory research, the relationship between short-working-long term memory generally is as follows.

Short-term memory: A few seconds.
Working memory: As long as consciously maintained.
Long-term memory: Permanent.

This ontology goes back to Baddeley and Hitch's work on the modal model of working memory from the 1970's, and has largely been maintained in subsequent item-based models (how most people think of human memory today).

Short-term memory isn't used as a formal construct very often in memory research anymore because it's a rather vague term, though I think perception researchers still use the term when they don't want to tread too far into memory theory. Instead, it's simply used colloquially as any means of remembering something over short time scales.


Why are people biased against overweight people? Several studies have shown that alot of people are biased to underestimate\undervalue overweight people:
http://www.npr.org/sections/13.7/2013/06/06/188891906/the-fat-shaming-professor-a-twitter-fueled-firestorm

Why is this?

It is easy to fall into an interpretive bias when evaluating the capabilities of overweight people. In other words, we understand that they are not as physically capable, and therefore undervalued/underestimated due to the interpretive bias.

Another thing is, similar to the idea of racism, Positive Distinctiveness kicks in. This is where, as humans, we see ourselves as part of a group (in this case, a non-overweight group) and we like to perceive our group as the more significant one. Unfortunately, one of the ways to perceive ourselves that way is by looking down on other groups (overweight people), and therefore they are undervalued.


Is this brain map scientifically correct? I'm not an expert in neuroscience but always read about information that seems conflicting to me. On one side I hear that the idea of single brain functions localized in specific brain areas is incorrect since everything is processed globally and on the other side I come up permanently with such kind of depictions of the brain

Can someone tell me how far this is correct or incorrect?

The diagram is a somewhat simplistic representation of brain functions, but it is accurate. The diagram given shows the primary areas that complete the actions listed. However, the entire brain is connected and communicates with itself extensively, so it isn't like the occipital lobe is the only brain region active when you see something.

For example, when you see an object, it is first processed in the occipital lobe as this is where the primary visual cortex is located. However, after the actual image itself has been processed, signals are sent to other brain regions for further interpretation. So if you see an angry dog running at you, the signal will begin in your occiptal lobe to process the visual image itself, but signals will then be sent to the temporal lobe to create an emotional response and to the frontal lobe to begin defensive motor activity.

  On one side I hear that the idea of single brain functions localized in specific brain areas is incorrect since everything is processed globally and on the other side I come up permanently with such kind of depictions of the brain

While these two explanations may seem conflicting, they are both somewhat correct. The diagram shows where primary processing of each task takes place, but it takes global communication to accomplish many of the complex tasks carried out by the brain. If there is a disconnect between the occipital lobe and parts of the temporal lobe, you will still be able to see just fine but may not have an emotional reaction to what you see. Vision is technically intact, but the full visual experience is damaged.

Just remember that diagrams like the one shown show you primary processing locations, but signals are sent between many brain regions to accomplish the full range of tasks carried out by the brain.

For further reading on the topic, this website offers a longer but still easy to understand explanation of current findings in brain connectivity: https://www.livescience.com/40855-brain-connections-no-neuron-is-an-island.html

Reference:
Kolb, B. & Whishaw, I. Q. (2009). Fundamentals of Human Neuropsychology: Sixth Edition. New York: Worth Publishers


How do you call a study in which subjects were deceived about the real purpose? Is there any “official” term to describe a study in which subjects were deceived about the real purpose of the research?

I am talking about studies that purposefully hide the real research questions from the subjects so as to prevent demand effects from influencing the results.

To make it more explicit: In my case, I tell people to watch a series of video clips from an online portal to describe the contents. What people don't know is that some of the videos are (purposefully) significantly distorted. I record their reactions to it (e.g. physiogically) — but people still think they're just describing videos.

The relevant section 8.03 in the APA Ethical Principles of Psychologists and Code of Conduct does not employ a proper term. In the literature, »deception/deceptive study/experiment/method(s)« are sometimes used, however not in the sense of a technical term – most often the matter is paraphrased as in »studies that use deception«.

The Milgram experiment(s) prominently employed deception, and the latter is most often discussed in the context of social psychology. On the other hand, there are much less clear cases. Robin Kramer in his comment is right that often it is not clear for the subject which variables are actually measured by some technique in a straightforward sense – think of a questionnaire that is part of a job application procedure, or e.g. indirect techniques for measuring attitudes.

Since deception as a clear-cut methodical device has been prominently used in social psychology, let's take a look at a popular text book:

  In this kind of experiment, it’s essential that the participant experience contrived events as if they were real; this is called a deception experiment. Deception in social psychological research involves misleading participants about the true purpose of a study or the events that transpire. (Aronson/Wilson/Akert/Sommers (2016): Social Psychology (9th ed.), p. 46)

Finally, Aronson et al. (2016) give the following references:

Christensen, L. (1988). Deception in psychological research: When is its use justified? Personality and Social Psychology Bulletin, 14, 664–675.
Epley, E., & Hu , C. (1998). Suspicion, affective response, and education benefit as a result of deception in psychology research. Personality and Social Psychology Bulletin, 24, 759–768.
Finney, P. D. (1987). When consent information refers to risk and deception: Implications for social research. Journal of Social Behavior and Personality, 2, 37–48.
Gerdes, E. P. (1979). College students’ reactions to social psychological experiments involving deception. Journal of Social Psychology, 107, 99–110.
Sharpe, D., Adair, J. G., & Roese, N. J. (1992).
Twenty years of deception research: A decline in subjects’ trust? Personality and Social Psychology Bulletin, 18, 585–590.


Stability of Personality and Formation As an economist I'm interested in what shapes personality and Indeed whether or not personality/traits change over time. For example, does personality change when placed in a high pressure environment, let's say a demanding job. Or does a demanding job attract those with a certain personality. I would have thought it would be a combination of the two. I presume significant life events would shape personality to some degree. Furthermore, is personality something that's formed in childhood or is it more biological. Is our personality always evolving? I apologize if this seems trivial! Economists are not renowned for their knowledge of Psychology.

Actually some if not all of your question can be answered fairly succinctly by quoting from a fairly recent meta analysis cited in the Wikipedia page on the topic:

  The longitudinal stability of personality is low in childhood but increases substantially into adulthood. Theoretical explanations for this trend differ in the emphasis placed on intrinsic maturation and socializing influences. To what extent does the increasing stability of personality result from the continuity and crystallization of genetically influenced individual differences, and to what extent does the increasing stability of life experiences explain increases in personality trait stability? Behavioral genetic studies, which decompose longitudinal stability into sources associated with genetic and environmental variation, can help to address this question. We aggregated effect sizes from 24 longitudinal behavioral genetic studies containing information on a total of 21,057 sibling pairs from 6 types that varied in terms of genetic relatedness and ranged in age from infancy to old age. A combination of linear and nonlinear meta-analytic regression models were used to evaluate age trends in levels of heritability and environmentality, stabilities of genetic and environmental effects, and the contributions of genetic and environmental effects to overall phenotypic stability. Both the genetic and environmental influences on personality increase in stability with age. The contribution of genetic effects to phenotypic stability is moderate in magnitude and relatively constant with age, in part because of small-to-moderate decreases in the heritability of personality over child development that offset increases in genetic stability. In contrast, the contribution of environmental effects to phenotypic stability increases from near zero in early childhood to moderate in adulthood. The life-span trend of increasing phenotypic stability, therefore, predominantly results from environmental mechanisms.

(emphasis mine) And since the abstract is somewhat devoid of figures... later in the article the contributions are quantified:

  Heritability tends to be high and accounts for the large majority of variance in infancy. Heritability declines substantially in early childhood and somewhat more slowly thereafter, resulting in roughly 40% of variance in personality attributable to genetic influences throughout adulthood. Environmentality displays the opposite pattern. Corrected for measurement error, environmentality shows a similar upward trajectory with a peak of accounting for over 40% of variance in personality. [...]  By midlife, genetic and environmental effects were found to contribute almost equally to phenotypic stability.

That half-and-half figure may be somewhat easy to misinterpret though. That's because environment doesn't necessarily mean present environment, i.e. someone's personality may be substantially affected by past events that are not easy to "undo" (counter-effect). More recent research has put the combined figure of stable influences affecting personality (e.g. genes, past environment, considered as a whole) to 83%. That sounds fairly consistent with voluntary attempts at changing one's personality having relatively small effect.


Why do some people seem to disregard the choice of doing nothing (The Zero Choice)? In many areas of life we have a choice between multiple options: if we are hungry and we want to go out to eat, we have a number of places to choose from (McDonalds, etc).  However, we also still have the 'Zero Choice' (my terminology) of not eating out at all and getting food some other way.

In my personal life, I've noticed (perhaps falsly) that a fair number of people, once they've made a general choice (in the example: eating out), they disregard the 'Zero Choice' (not eating out) and become fixated on the sub-choices (where to eat out).

Is there a noticable difference in mental activity between people who don't consider the 'Zero Choice' and people who do?

Original Question:

  In my life I've noticed that people rarely see the 'nothing' choice.
  Rather than choosing this or that, there is also the choice of
  neither and both.  People I've interacted with often weigh their
  both, this, and that options fairly well, but many completely
  miss the neither/nothing option.

  More specifically, I've seen this in a couple girlfriends I've had and
  a couple guy friends also.  When trying to decide what to do, they'll
  settle on a type of activity (active/passive -> general category ->
  couple options) and then choose between a couple options.  However,
  rarely in these options do they include the idea of something
  completely different.  Meanwhile, this is something I do without
  thinking; other options are always present to me, and I have no
  difficulty in seeing, weighing, or choosing the neither option.

  These are poor examples and for that I apologize; but is this a
  recognized phenomenon? What neural differences are there between
  people who process the nothing option and people who don't?

  Has this even been researched at all?  Cursory Googling (the most
  available to me right now) has revealed nothing; I could be searching
  for the wrong thing though...

More generally, you are asking about a common tendency to substitute a sub-set of  alternative actions for the entire set without realizing it.

Beyond the contribution of pure habit, it seems to be related to several common decision making biases, including attentional bias and focusing effect, though it doesn't exactly match any.  I don't recall seeing this investigated directly.

"Zero choice" is a poor choice of terminology, it evokes the "null hypothesis" (as Ben Brocka alluded to in the comments), which in decision making usually means "do nothing", not a call to consider a broader set of alternatives.


Can people act randomly? Let's imagine an experiment. We will tell N normal people that they need to act randomly in the Rock–paper–scissors game (in this game Game Optimal Strategy is to choose an action with uniform probability 1/3).
Two question:

How close to uniformly randomness can we expect each person to act?
More important question. Will this be a stationary distribution or it will change over the time if there will be a lot of trials?

(People in the experiment can't use any kind of external random generators).

A nice psychology article (media article) that provides answers to your question can be found at here. I will try to summarize briefly based on this article.

  How close to uniformly randomness can we expect each person to act?

The short answer is no. As explained in the article, on the first round of Rock-Paper-Scissors it is less likely that a randomly selected person will choose paper over scissors or rock. Moreover, as two people play many rounds of Rock-Paper-Scissors together, they tend to not play randomly but adjust their selections based on whether they won or lost.

  Will this be a stationary distribution or it will change over the time if there will be a lot of trials?

There are many definitions of stationary, but a paper mentioned in the above article found cyclical behavior which would violate some of the definitions of stationary. However, this might still fit into some definitions of stationarity.

While I'm unaware of a particular article which addresses the question of wide-sense stationary in this game, I would be surprised if this were found in Rock-Paper-Scissors played between humans. There is an interplay of affective (emotional) and rational decision making that tends to be influenced by the actions of human opponents.

I would be less surprised if this were found when a human plays a computer, especially if they knew the computer was playing completely randomly. People play different strategies in games played Human vs. Human as opposed to Human vs. Computer (e.g. the Ultimatum Game)


Why does autism sometimes only visibly appear later in life? From what I know about the autism spectrum, a lot of people who were diagnosed later in life (not during childhood) didn't "seem autistic" until adolescence or young adulthood. Of courses, they had symptoms all this time but it didn't become obvious until later.

Why is that? Do you have some articles/youtube videos that I could read/watch to learn more about this (English or French)?

It is important to remember when reading this question and answer is that Autism Spectrum Disorder (ASD) does not develop in adulthood, but symptoms can change for individuals over time because learning occurs.

Symptoms of ASD come in all shapes and forms because this is a spectrum disorder and therefore people present somewhere on a spectrum, often referred to as from low functioning to high functioning.

To answer the question directly, people who present symptoms later in life, as you say, often do present those symptoms in childhood but they aren't noticed by the adults in the child's life until it becomes a real problem for the individual.

As an example, interpersonal skills are learned during childhood. It is perfectly acceptable for children to be at slightly different stages during development with regard to interpersonal skills. Some children will be more advanced then others. Interpersonal skills can be difficult for people with ASD to grasp and so someone with high functioning Autism can take longer to develop these skills, if they are developed at all. So that would potentially not show up until later when the other kids have developed these skills and the child with undiagnosed ASD has not.

Often, 30+ years ago, before we had more advanced treatments and assessments children would 'fall through the cracks' and be labeled as gifted, rather then as having high functioning ASD. This would explain why some people who are highly successful in adulthood are diagnosed in adulthood rather then childhood. People with high functioning ASD often have a savant type qualities, meaning they are very skilled in some specific area.
The diagnostic criteria (DSM) has been amended over the years which would account for some adults being diagnosed now, as they may not have qualified before the DSM changed the criteria.

This would be an interesting study to read to understand social interaction among children with high functioning ASD: Bauminger, N., Solomon, M., Aviezer, A. et al. J Abnorm Child Psychol (2008) 36: 135. https://doi.org/10.1007/s10802-007-9156-x

This article discusses changing symptoms (Behavioural) in youth and adults with ASD.

This might be a good book for you to read together a good understanding of ASD in development, which might give you a better understanding as to why people can go undiagnosed until adulthood. Handbook of autism and pervasive developmental disorders, 2nd ed.

In conclusion, There are many reasons that someone might not be diagnosed until later in life, and autism is a spectrum which means people have many different symptoms that range on a vast scale.

References

Bauminger, N., Solomon, M., Aviezer, A. et al. J Abnorm Child Psychol (2008) 36: 135. https://doi.org/10.1007/s10802-007-9156-x

Shattuck, P.T., Seltzer, M.M., Greenberg, J.S. et al. J Autism Dev Disord (2007) 37: 1735. https://doi.org/10.1007/s10803-006-0307-7


Does dreaming cuts our sleeping hours? If I am dreaming a lot at night, how many effective hours am I sleeping at night?
After dreaming heavily at night, when I wake up in the morning I feel sluggish as if I haven't slept properly.

Does dreaming cuts our sleeping hours?

One small study (2015)  in otherwise healty subjects, found no correlation between nightmares and the quality of sleep measured using widely used objective methods, or more precisely

  sleep measures obtained by ambulatory polysomnographic recordings revealed no group differences in (a) overall sleep architecture, (b) sleep cycle duration as well as REM density and REM duration in each cycle and (c) sleep architecture when only nights with nightmares were analyzed.

Nonetheless the subjects who experienced nightmares reported worse self-reported sleep quality. Granted, in a study like this, there's always a chance the authors failed to consider some objective sleep measure not commonly known/used today. Anyhow, the author's' conclusion was that

  nightmares result in significant impairment which is independent from disturbed sleep architecture

And thus they suggest one seek specialized treatment for nightmares... which are correlated with quite a few psychiatric disorders, PTSD, anxiety, depression, or borderline personality disorder, to name a few.

Another caveat of this study is that the authors deliberately excluded people with diagnosable psychiatric conditions from the sample. So this study does not exclude the possibility that subjects with (say) PTSD actually do have worse objective sleep... owing to nightmares.


Do the colour blind have a distinct visual cortex structure? Studying the structure of the visual cortex, it seems there are many neural structures specifically dedicated to detecting and interpreting colour. For example, parvocellular cells are particularly sensitive to colour. Consequently, in a colour blind person, are parvocellular cells or other neural structures less prominent? What are the differences in brain structure between a colour blind person and a normal seeing person?

Interesting question! I performed a fairly extensive search in Google Scholar and Scopus using various keyword searches, including, but not limited to "color blindness and plasticity", "color blind and brain", "dichromates brain", and "monochromates brain". Strikingly, I found nothing. The reason is aptly explained by Solomon & Rosa, 2014 and I quote from their interesting review:

  As yet no anatomical correlates of color blindness have been found in the retina (Chan and Grünert,1998; Chan et al.,2001; Jusuf et al.,2006a,b), thalamus, or primary visual cortex (Goodchild and Martin,1998; Solomon, 2002).

If desirable, you should be able to re-trace the relevant citations from the cited review, as it is open source.


What tools exist to measure work meaningfulness? Do you know of methods/tools/criteria used (in sociology, social psychology or occupational science) in order to evaluate how meaningful some particular work can be for a particular person?

I am not asking what (in general) could make work meaningful, but whether some models/tools/lists of questions exist that can be used to measure someone's perception of his own work's meaningfulness.

I've come across a few tools such as the "Meaningful Activity Wants and Needs Assessment" (regarding life balance, more than occupational meaningfulness), "WAMI Work and Meaning Inventory", and a few other tools aimed at assessing job satisfaction, work motivation, etc.

I wonder if other formal models/tools could be suggested.

There are a bunch of them! For a great review of many definitions and measures of meaningfulness, see if you can get a copy of A Narrative Evidence Synthesis of Meaningful Work: Progress and Research Agenda. The authors are pretty responsive in my experience and will send you a copy.

One thing to keep in mind, though, is that there are a bunch of different definitions of work meaningfulness. Everybody has their own approach, some are better than others (i.e., more likely to actually measure meaningfulness and not something related like engagement or intrinsic motivation), and there isn't really a consensus yet. The WAMI you mentioned is built by highly-regarded meaningfulness researchers, is very commonly used in studies of meaningfulness, and I think it's a great "safe bet" measure for getting overall work meaningfulness.

However, if you're looking to zoom-in a little and look at sources of meaning (is it the challenge of your work that you find meaningful, or bonding with coworkers?) like those described in On the meaning of work: A theoretical integration and review, then you might want to check out the Comprehensive Meaningful Work Scale.

Hope that helps!


Why do people often do unnecessary things while performing a main task? And this is not about procrastination (I'm almost certain).

I've been noticing it since childhood that people (me included) tend to do unnecessary side activity, especially if they're invested in the main activity.

Examples of main activity: having a thoughtful conversation, watching an interesting movie, crafting something manually.

Examples of side activities: doing tricks with a pen, playing with shirt buttons, doodling, tearing a piece of paper into smaller parts, attaching and detaching magnets, in other words almost anything slightly amusing/interesting/touch-pleasant.

The side activity tends to increase with the intensity of main activity, only ceasing at the point where the main activity takes all the concentration a person can manage to attain.

What causes this? Does it somehow help us perform the main activity? Then how exactly? Or is it a reaction to performing something effortsome?

In the whole scheme of human consciousness, these movements may be a result of what one individual person's autonomic and central nervous system has been conditioned to expect. While awake during different hours of different days, implying different variables to be present depending on [social code] etc, our central nervous system (CNS) has a threshold for response- the level of response/arousal to sensory input accompanied by these variables stated above will ultimately help someone read what their basal level of arousal is. If that basal level arousal is not met in a certain social context (this basal level has increased via techna-cultural advancement) than the body may expend this energy via other methods of movement or concentration.


Is all learning a subconscious activity? As a non-native English speaker I recently tried to understand difference in phrases "to study" and "to learn". I found some explanations here on English language and usage SE, stating that learning is a subconscious activity. Then in some articles I've found, authors stated that language learning is subconscious and that acquiring knowledge and skill isn't the same  [ also that learning language is actually learning a skill, while learning history is acquiring knowledge.] .

So I got confused : is all learning subconscious or not?

Is there a difference in learning language and learning anatomy, laws of physics or programming?

Additionally some articles got me confused, especially  those that want to sell you hypnosis  DVDs and instruction manuals to "boost" your subconscious mind. Aren't we already equipped with proper subconscious mind?

We should not confuse the psychological terminology of consciousness, the subconscious and the unconscious with the lay meaning of activities being performed consciously or subconsciously.
The distinction between "conscious" learning and "subconscious" acquisition of linguistic knowledge goes back to the Monitor Model that linguist Stephen Krashen developed in the 1970s and 1980s. According to this theory, human beings develop linguistic skills in two ways: either we

"subconsciously" acquire knowledge, without realizing that we do so (e.g. by growing up in a certain linguistic environment), or we
"consciously" learn (e.g. by memorizing lists of words in a foreign language).

Krashen's theory has been both praised and criticized, but this is not the place to go into that debate. It should be enough to note that the hypothesis has as yet not been empirically proven.
From a psychological point of view, learning – of which acquisition is a part, namely that a response to a stimulus has been established – is always not conscious. A conscious activity is one that we are aware of (like intentionally putting a book on a shelf), but learning, that is: the storing of information in the brain, takes place through processes of which we are unaware and in parts of our anatomy over which we have no control.
For example, when you try to memorize a foreign word and its meaning, you cannot consciously put that knowledge in your memory like you can place a book on a shelf. What you must do, for example, is repeat the information until you no longer forget it. But you have no awareness of wether or not the storage was successful. You can only deduce that success from your ability to retrieve the information (i.e. correctly remember). A conscious storage would give you a direct (sensory) feedback of the storage process, similar to how your eyes show you wether or not the book is now on the shelf. If the placing of a book on a shelf worked subconsciously like storing knowledge in your brain, you'd have to retrieve the book from the shelf again to know that it had been put there. Until you took it off the shelf, you couldn't know if it was actually there.
So to answer your question:
For a psychologist, all learning is "subconscious" (but he would not use that word).


What is the opposite of an insult for the purposes of triggering lasting positive affect? Over the centuries, western cultures have developed dozens of swear words, insults and curse words that are intended to trigger acute negative affect in the recipient. If one particular word does not work, the insulter would typically cycle through the words until he/she finds the one that "strikes a chord" and causes the intended level of emotional distress.

What interests me is that the right insult quickly triggers emotional pain. Unless a person knows how to mitigate the effect, the negative emotion is likely to stay with the person for minutes to hours.

This makes me ask - What are there opposite of insults for the purposes of triggering positive emotion that lingers on afterwards?

Is there some kind of word or action that instantly triggers positive emotions of equal magnitude? Terms like praise come to mind, but I'm not sure praise is as powerful as insults.

The words we use have no inherent capacity to evoke negative or positive affect.  Instead, how we appraise, reappraise, attend to, and reflect on those words determines our affective response (e.g., Gross, 1998; Siemer, Mauss, & Gross, 2007).

For example, you could tell one person "You are stupid" and he/she might become extremely upset.  You could tell another person the same thing, and he/she would have no affective response.  Similarly, telling someone "You are nice" could make someone very happy or not change his/her mood at all.

So how can we predict who will respond most intensely? Philippe Verduyn  and colleagues (2009; 2011) have looked at predictors of greater emotion response duration, which include:

The salience of the emotion-eliciting event
How you conceptualize your positive/negative affect (joy lasts longer than anger, which lasts longer than fear)
Intensity of the emotion at onset
Physical reappearances of the emotion-eliciting stimulus
Stimulus-related cognitions with the same valence as the emotion
Social sharing (consistent with Bernard Rimé's work)

How one chooses to regulate their emotions in response to an insult or compliment would also influence emotion reactivity and duration, including tendency to distract oneself from the stimulus (Sheppes et al., 2014) or skill in reappraising the situation (e.g., McRae et al., 2012).

We would also expect depressive rumination (see Susan Nolen-Hoeksema's work) and positive rumination or savoring (e.g., Feldman, Joormann, & Johnson, 2008; Quoidbach, Berry, Hansenne, & Mikolajczak, 2010) to predict intensity of responses to insults and compliments, respectively.

Conclusion

So the point is that there are no special words or phrases that will reliably evoke some level of positive affect.  Instead, the emotional intensity evoked by a stimulus depends on the salience of the stimulus, proximity to the stimulus, and individual differences in emotional responding (i.e., reactivity and regulation; see Gross & Barrett, 2011).  If you take these into account, you can devise more powerful insults and compliments.


Does electricity pass through synapse? As far as I understand, when a neuron fires the action potential generated in a cell body reaches only the presynaptic part of the synapse, then triggers the transmitter to pass through the gap, and that transmitter causes the membrane in the postsynaptic part to open ion channels, pumps, etc ..., which generate a completely new electric potential that finally reaches the receiver cell.

So the electricity generated in a firing neuron never actually reaches receivers (not directly)?

Yes – electricity does pass through synapses if the link between the neurons in question is constituted by an electrical synapse.

There are two different types of synapses, chemical synapses and electrical synapses.

At a chemical synapse, an arriving pre-synaptic action potential indeed causes the release of neurotransmitters which carry the signal across the synaptic cleft to the subsynaptic membrane. This can effect an action potential in the postsynaptic neuron (among other things).

At an electrical synapse, on the other hand, ions do actually move from the presynaptic cell, through a gap junction channel, and to the postsynaptic cell, capable to cause a depolarization there.

Electrical synapses are found in many animals (including human). Due to their different characteristics, like the lack of neurotransmitter-related mechanisms and a significantly smaller synaptic cleft, they e. g. allow for a faster propagation of a signal between two neurons (while the signal decreases in strength due to the lack of gain). They occur as a part of neural structures which require fast signal transmission.

(While more technical details can be found in the referenced sources, it is helpful to review some of the basic concepts to avoid misconceptions:

It is sometimes (naively) assumed that the propagation of an action potential consists in a flow of electric charge along the axon, but what actually happens is that ions move through the membrane, i. e. roughly along an axis that is orthogonal to the direction of the signal. It is the action potential that moves along the axon. Thus, the original question is not to be taken to mean »Does the electric current that moves along the length of the axon also move through the synaptic cleft?«

Still – even if the flow of electric charge does not constitute the action potential, electricity can flow along the axon, as well. This is what happens in the case of saltatory conduction between the nodes of Ranvier in myelinated axons. It is generally referred to as an electrotonic potential.)


Do unequal step sizes in staircase procedure affect the convergence? Consider a psychophysics procedure using a standard staircase method to adaptively find the threshold, using a 2AFC paradigm and a 1-up, 3-down method to determine the 75% threshold. Now suppose the use of steps that are unequal in size. I am not referring to decreasing the step size after a certain amount of reversals as described by Levitt (1971), but to the use of unequal step sizes. So for example suppose that the available steps are 0.5 - 0.5 - 0.5 - 1 - 1.5 - 0.5 - 2.5 - 2. So this would translate to a discrete set of available stimulus levels of: 0 - 0.5 - 1 - 1.5 - 2.5 - 4 - 4.5 - 7 - 9. Since step size can be used to alter the correct rate at which the staircase procedure converges (e.g., 50%, 75% etc.) Kaernbach (1991), I was wondering what my proposed stimulus-level distribution would mean for the threshold definition of a 1-up 3-down procedure intended to converge onto a 75% threshold?

It is going to mean bad things. If you can only create stimuli with a predefined non uniformly sampled set of "levels" then the the corresponding percent correct that the staircase will track will depend on the threshold of an individual observer. For example, if you can create stimuli with levels of 0, 1, 2, 3, ..., 100, 110, 130, 170, 250, 410, where for small levels the up and down step sizes are equal, but for large levels the up step size is twice the down step size. This means the percent correct point is going to be different depending on the threshold of the subject. You wouldn't have to worry about it if you use something like the method of constant stimuli.


How does timing of pleasure / dopamine / reward influence the formation of positive association? Suppose the following idealized experiment:

Setup:

A pill/medication which simply induces pleasure. Perhaps something like a perfect dopamine antagonist with no side-effects. Call it P
A task which is to be trained. Call it T. (Assume that  T is not intrinsically pleasurable or unpleasant, and has no unpleasant associations for the subject)

Goal: The subject of the experiment is to be introduced to T in such a way that reinforces the "enjoyment" of  T and the desire to again do task  T.

Variables: P can be administered any time -- before during or after -- task T.

Question:

a. Is there an optimal time to introduce P to facilitate the development of the desire/interest/motivation to do task T?
b. Is this even possible if the subject knows that P induces the pleasure?
c. Even if pleasure and T are then linked, is it only under the assumption that T leads to pleasure, and thus if P is no longer present, the interest in T will wane?

i will offer an answer to this, because i don't believe this is homework. see next comment below:

  Perhaps something like a perfect dopamine antagonist with no
  side-effects. Call it P

no, let's call it an antipsychotic. perhaps P stands for prochlorperazine. i think you mean dopamine agonist. dopamine antagonists invoke what could best be described as a chemical lobotomy, and are antithetical to any notions of motivation, salience, achievement, or reward.

  a. Is there an optimal time to introduce P to facilitate the
  development of the desire/interest/motivation to do task T?

yes -- immediately once the desired behaviour has been undertaken successfully. with some interesting exceptions e.g. food poisoning, the shorter the latency between any behaviour and its consequences, the stronger the association between the two will become apparent to the individual. think of it as a "theory of causality" -- the shorter the latency, the more confident we become that the behaviour caused the outcome.

this is why the route of administration of a drug has a strong influence upon an individual's susceptibility to addiction, or to put it another way, motivation to consume the drug again. smoked or IV versus oral administration. conversely, it's much harder to engage in behaviours that might be beneficial to us years down the track because we have less confidence that engaging in that behaviour will result in the desired outcome.

  b. Is this even possible if the subject knows that P induces the pleasure?

yes. however, if there is no intrinsic motivation to do the task, it will be much harder to facilitate the desired behaviour in the absence of the reinforcer. if you only did something because of the outcome, and not because you found some inherent enjoyment from it, after a while you might start thinking about other behaviours you could engage in to attain the same outcome.

in the case of our fictional substance P: sure, i could keep doing what you want me to in order to obtain it. but in engaging in your task as simply a means to an end, i might start to consider more direct routes to that same end. for example, i could steal the keys to your medicine cabinet. or place a blood-filled syringe to your neck and tell you to hand it over.

  c. Even if pleasure and T are then linked, is it only under the assumption that T leads to pleasure, and thus if P is no longer present, the interest in T will wane?

yes. here, new learning takes place: the individual has now constructed a new theory of causality. whereas once upon the individual learned that engaging in T offered access to P, it now no longer does.

i would go so far as to argue that if one was not aware of the presence of P, one's interest in the task would persistent for far longer a period, and perhaps indefinitely. "perhaps i'm not doing the task correctly... i know, it's because i've had a lousy week... " etc, etc. one might even start engaging in superstitious behaviours in the belief that it is this superstitious ritual that influences the likelihood of the reward.

in order to "slow down" this new learning (extinction), it would be important to ensure that the reinforcement of T with P is not 1:1. the more tightly a behaviour is linked to an outcome, good or bad, the more one expects the outcome to occur when they engage in that behaviour. when the outcome is now absent, the more apparent it is that something about the behaviour -> outcome relationship has changed.

to understand how this works, read into the relationship between different reinforcement schedules and rate of extinction. also read into the phenomenon of spontaneous recovery.

now, you will need to excuse: my motivation to continue typing has now waned, and in it's place, a desire to go get high.


Why does learning new mental skills lead to headaches? Why is deliberate practice uncomfortable? For example, during learning college math and playing the piano. Why do we get headaches after long hours of practice?
According to this question, learning is about connecting distant neural networks; in forming these synapses resources are recruited such as calcium and glucose.
Now since the brain has no pain receptors, the discomfort must be coming from the surrounding nerves in the skull and neck. Possibilities:
a) Requiring greater resources is straining our blood system and hence the pain.
b) Forming many connections continuously creates excess of neurotransmitters such as glutamine that strain and literally swell brain areas, which in turn hit against our skull nerves.
Please feel free to correct me.
This topic is closely connected with the cellular mechanism of mental fatigue.

Migraine and tension-type headaches are an important burden in many people's daily lives. This is not my direct research topic. But as far as I have read on the subject headache has been related to posture problems and vision problems. Some studies point to an increase in headache complaints, related to increased hours of study online. But this can also be related to posture and vision (tired eyes or dry eyes). Of course, the occurrence of headaches can affect the quality of the study (and acquisition of new skills), but estimating the opposite apparently still lacks proof. I leave below some links of articles about the subject that may be of your interest:
Behavioral Treatments for Headache,
Headache vs musculoskeletal pain vs vision problems
Headach - clinical setting


What's the memory capacity of the human brain? This article,

Human brain can store..

claims the memory has a capacity of around 1 petabyte or quadrillion bytes.

This other one,

What's the memory capacity of the human brain

claims the memory storage capacity is around 2,5 petabytes.

What's the memory capacity of the human brain? Or at least the most widely accepted estimate?

I don't know the answer to your question but I'm not aware of anyone who does.

The paper referred to in the first article above is Bartol et al. (2015) in eLife (https://cdn.elifesciences.org/articles/10778/elife-10778-v2.pdf). This paper is a proposal of how one might estimate the storage capacity of a synapse. Their current estimate is 4.7 bits per synapse. The article states that more work is needed to get an accurate estimate. The paper does not provide a definitive answer to your question. There is not much research on this subject at the moment, probably because there are still many things we don't yet know about the nature of memory. In time we may find that a completely different method to Bartol's gives a better estimate.

The figure of 1 petabyte is not given in Bartol's paper. This value may have been given in the press release or it could have been calculated by the journalist (by multiplying the estimated synapse capacity by an estimated number of synapses). The estimate of the number of synapses in the brain is the subject of research itself. Bartol's paper says that there are 'many trillions of synapses', which doesn't give us enough information to calculate. The figure needed to get 1 petabyte is around 200 trillion synapses, if my maths is to be trusted. The figure of 1 petabyte is the product of two estimates that may or may not be right, so it's probably not reliable.

The second article is a Professor's response to this question. He says, in essence, that we don't yet know the answer and it would be difficult to calculate.

We still have so much to learn about memory. I suspect it will be some time before we know the answer to your question.


PTSD is an internalising disorder or mixed? I am a bit confused. In an open access article (Caspi, et al. 2020), is the following — under Methods: Assessing Psychopathology (emphasis mine):

[...] externalizing disorders (ie, attention-deficit/hyperactivity disorder, conduct disorder, alcohol
dependence, cannabis dependence, other drug dependence, and tobacco dependence),
internalizing disorders (ie, depression, generalized anxiety disorder, fears [including social phobia, simple phobia, agoraphobia, and panic disorder], posttraumatic stress disorder, and eating disorders
[including bulimia and anorexia]), and thought disorders (ie, obsessive-compulsive disorder, mania,
and schizophrenia)

I can understand that PTSD will be caused by internalisation of the trauma experience(s), but from my experience, elements of PTSD often involve externalising (hypervigilence for example) and sometimes unhelpful thoughts/behaviours (for example, fear of all people of a certain religion, culture, background and/or gender; and to the extreme, violent tendencies towards those people to "prevent" further traumatising events).
So is PTSD just an internalising disorder, or can it be a mixture of an internalising, externalising and thought/behaviour disorder?
References
Caspi, A., Houts, R. M., Ambler, A., Danese, A., Elliott, M. L., Hariri, A., ... & Rasmussen, L. J. H. (2020). Longitudinal Assessment of Mental Health Disorders and Comorbidities Across 4 Decades Among Participants in the Dunedin Birth Cohort Study. JAMA Network Open, 3(4), e203221-e203221. https://doi.org/10.1001/jamanetworkopen.2020.3221

My understanding is that the internalizing/externalizing dichotomy refers to the way symptoms are expressed, not the source/cause of the disorder. Internalizing disorders are those that mostly have an internal impact and tend to lead sufferers to withdraw or hide their affliction. Externalizing disorders tend to impact others more directly with outward-focused behaviors. Therefore, I don't think hypervigilance would be considered an "externalizing" feature even though it is directed at the outside world, because all that is directed outward is attention; the primary impact on the individual is the internal mental stress that maintaining a hypervigilant state creates. Outbursts of violence clearly would be "externalizing", however.
The DSM-5 doesn't categorize by internalizing/externalizing, and puts PTSD in the category of "Trauma- and Stressor-Related Disorders". The DSM-5 mentions specifically the combination of internalizing and externalizing symptoms in these disorders:

In some cases, symptoms can be well understood within an anxiety- or fear-based context. It is clear, however, that many individuals who have been exposed to a traumatic or stressful event exhibit a phenotype in which, rather than anxiety- or fear-based symptoms, the most prominent clinical characteristics are anhedonic and dysphoric symptoms, externalizing angry and aggressive symptoms, or dissociative symptoms.

In the paper you refer to, the authors did group PTSD with the internalizing disorders. They've done this in reference to a previous paper which identified three factors, labeled Internalizing, Externalizing, and Thought Disorder, that together explained well the spectrum of conditions. However, PTSD is not really involved in this paper.
It's unclear why they chose to include it as "internalizing" in the Caspi 2020 paper, except that their approach meant that if they included it at all it had to be placed in one of those three categories. Given the other items on the list, I think it's quite reasonable to group PTSD along with anxiety, phobias, and depression, rather than among substance dependence or schizophrenia, but I don't think this should be taken as anything but a choice of designation within the scope of this particular paper.


Is critical thinking associated with IQ? I consider myself a person with reasonable intelligence. In my job, I require a lot of critical thinking. I am good at think laterally, but sometimes I feel I missed important critical evaluations of a simple problem. Then, I start to doubt my own intellect and rationality.

Is critical thinking associated with IQ?

Critical thinking is an ill-defined concept in the cognitive sciences, so this question most likely has as many answers as there are measures of IQ and critical thinking. An accessible introduction to the literature is available here, with the general cognitive conception of critical thinking given as follows:

  ... the mental activities that are typically called critical thinking are actually a subset of three types of thinking: reasoning, making judgments and decisions, and problem solving. I say that critical thinking is a subset of these because we think in these ways all the time, but only sometimes in a critical way. Deciding to read this article, for example, is not critical thinking. But carefully weighing the evidence it presents in order to decide whether or not to believe what it says is.

With that said, there appears to be some empirical support for a relation between cognitive ability/IQ and critical thinking ability, at least within a dual-process theoretic framework. Sá, West and Stanovich (1999) reported:

  Participants high in cognitive ability were able to flexibly use prior knowledge, depending upon its efficacy in a particular environment. They were more likely to project a relationship when it reflected a useful cue, but they were also less likely to project a prior belief when the belief was inefficacious.

I've provided a link to the PDF my references, since they refer directly to cognitive ability rather than IQ, and the equivalence is only made clear in their Method section.

References

Sá, W. C., West, R. F., & Stanovich, K. E. (1999). The domain specificity and generality of belief bias: Searching for a generalizable critical thinking skill. Journal of educational psychology, 91(3), 497.


How to assign numbers to response options on a bipolar scale? Does it matter which one of the three scales we use: A, B, or C in the attached questionnaire? Each one will have a different interpretation of the data. Please advise how should we analyze the bi-polar items of this questionnaire. Thank you.

Yes, it matters, and you should probably go with scale B if you have to use numbers. See my answer here on Cross Validated in response to, "Is 0 a valid value in a Likert scale?" The zero in the middle of A is confusing (this isn't to say I don't understand it, but do you really trust that every respondent you ever come across will?), but even if you were to replace it with 4 and add 1 to the options currently labeled 4–6, you might get different answers than if you go with (-3)–(+3). Either way, there's some connotation of "less" applied to the options on the left, which may bias responses. Option C even confuses me, so I'd say you should throw that out completely...

IMO, the safest bet would be to label your rating options with words, not numbers. To make responding easy, let people check boxes or provide abbreviated codes for their preferences such as "Strongly prefer left option" = SL or "Right option is a mildly better fit" = Rm. Here's how I presented these suggestions in my other answer, and the supporting reference (Schwarz, Knäuper, Hippler, Noelle-Neumann, & Clark, 1991):

  Allow respondents to check cells in a table corresponding to their answer preference: each row can be a different item, and each column can be labeled with your rating anchor, or vice versa – no numbers involved. Here's how that might look (if one were to answer wisely):

  $\begin{array}{|c|c|c|c|c|c|c|}\hline&\tiny\text{Strongly Disagree}&\tiny\text{Disagree}&\tiny\text{Mildly Disagree}&\tiny\text{Mildly Agree}&\tiny\text{Agree}&\tiny\text{Strongly Agree}\\\hline\tiny\text{Tumblers: better than pumpers!}^*&&&&&&\checkmark\\\hline\tiny\text{I look fat in this dress.}&\checkmark\\\hline\end{array}$*

  Wikipedia gives another style using marked options (by Nicholas Smith):

  Letter codes can also be substituted for numeric options if blanks are to be filled for a list of very many items; e.g., {SD,D,MD,MA,A,SA}. Just don't forget to include the legend!

  Reference
  Schwarz, N., Knäuper, B., Hippler, H. J., Noelle-Neumann, E., & Clark, L. (1991). Rating scales numeric values may change the meaning of scale labels. Public Opinion Quarterly, 55(4), 570–582.


How has geometry been applied in cognitive science? What areas of geometry are used in psychology/cognitive science/neuroscience? Are the applications of a sophisticated nature or superficial?

Here are a few off the top of my head from neuroscience:

neural activity may primarily exist on low dimensional attractors.
reconstructing PET signal origins from emitted gamma rays
It's widely believed our brains are gyrencephalic (wrinkly) to maximize surface area.
Various distance metrics (Euclidean, Mahalanobis) are common tools for clustering data, for example spike sorting.
Neuron morphology (shape) follows function.
Microgeometry of objects is important for tactile texture perception.
Bat echolocation and fish electrosensation are limited in range due to the inverse square law.


Where to obtain and how to score the Bukowski et al "Friendship Qualities Scale"? Where to obtain the Bukowski Friendship Qualities Scale?
How do you calculate the scores from it?

It might be available here but I'm not sure because I don't have access to the article: http://spr.sagepub.com/content/11/3/471.short

Bukowski, W. M., Hoza, B., & Boivin, M. (1994). Measuring friendship quality during pre-and early adolescence: The development and psychometric properties of the Friendship Qualities Scale. Journal of Social and Personal Relationships, 11(3), 471-484.

Obtaining: Yes, the items are listed in Bukowski et al (1994). See Table 1.
You could always email the author explaining your research project and ask him whether he would allow you to use the measure.

Scoring:
A quick look suggests that each item is scored on a 1 to 5 scale.
Table 1 suggests that there is a scale-level, and subscale-level of scoring (i.e., 5 scales, and 10 subscales). Table 1 shows how items relates to scales and subscales.

Scoring scales and subscales seems to be just a matter of getting the mean of constituent items.

References

Bukowski, W. M., Hoza, B., & Boivin, M. (1994). Measuring friendship quality during pre-and early adolescence: The development and psychometric properties of the Friendship Qualities Scale. Journal of Social and Personal Relationships, 11(3), 471-484.


How effective are multiphasic sleep schedules? Does multiphasic sleep work well enough that it can be used as a replacement for monophasic sleep?

Has there been any research done on people that have used bi/polyphasic sleep for extended periods of time?

Do multiphasic sleep schedules require different eating patterns?

Results from experiments with polyphasic sleep are (Stampi, 1992; as summarized in Pinel, Biopsychology):

Test subjects needed two weeks or more to get used to a polyphasic sleep cycle.
Once test subjects got used to their new sleeping pattern, they were happy with it and showed no deficits in performance tests.
Leonardo da Vinci's rhythm of 15 minutes of sleep every four hours works well.
Most test subjects slept too long, and were not refreshed, or too short, and were groggy for a few minutes after waking up ("sleep inertia").
At first, sleep is mostly slow wave sleep, but after some time the normal relation between slow wave sleep and REM-sleep re-asserts itself.

Stampi, C. (Ed.) (1992). Evolution, chronobiology, and functions of polyphasic and ultrashort sleep. Boston: Birkhäuser.

What I don't know and what would interest me:

In a normal monophasic night sleeper, among other things melatonin is high at night, body temperature is low, and, as your question hints at, there is a long break with no food intake. A polyphasic sleeper would disrupt these "natural" (i.e. corresponding to the rhythm of day and night) physiological rhythms, because he probably wouldn't spend his nightly wakeful hours inactive and in darkness. I don't know, what (longterm) effects this might have.

Stampi's book is rather old now, and I'm sure there is more recent research. Maybe some of these open questions have been answered by now.


How to distinguish mental illness and neurodevelopmental disorders? It looks like mental illness and neurodevelopmental disorders may look absolutely same if we superficially  observe the behaviour.
Example:

Anger, destructive behaviour can be either due to a mental illness (anxiety, panic disorder, mood disorders, etc) and also can be a meltdown that is seen in neurodevelopmental conditions (Autism, Aspergers, ADHD, SPD etc).

Stereotypy and stimming behaviour can occur due to either mental illness like OCD and severe anxiety or it may have a neurodevelopmental origin.

Anxiety itself, can be either of a psychological origin (such as either fear of something irrational, or just a state of fear), or it may have a neurodevelopmental origin such as the patient of ADHD or Aspergers or SPD can not handle a overstimulated state and may feel anxious if they have to wait for uncertain period.

There are a lot of other similarities between neurodevelopmental and psychological conditions.
Now suppose the scene a patient comes in the chamber of a General Physician/ Psychiatrist with complaints of restlessness, anxiety, depression, psychosomatic illness (nausea, headache, numbness), forgetfulness, lack of concentration etc. The general symptoms signal either a primarily psychological condition, or may have a neurodevelopmental origin. How the General Physician / psychiatrist should distinguish it?

As @BryanKrause said; mental illness and neurodevelopmental conditions are not distinctively separable.
Example: Neurodevelopmental hypothesis of schizophrenia,
Obsessions and compulsions in Asperger syndrome and high-functioning autism
Etc.


Are there cultures in which leadership/hierarchy does not exist? Unproven statement: Human cultures depend on the concept of leadership/hierarchy.

All the cultures I've seen until now depend on this concept. But I may be mistaked: It might be possible that my intuitive understanding of leadership/hierarchy is wrong. This addendum has the sole purpose of pointing the poorness in my idea (which might be important somehow).

  Question: Are there cultures in which leadership/hierarchy does not exist?

You may look for an answer in some anthropological works about hunter-gatherers, e.g. Christopher Boehm's Hierachy in the Forest. Basically, he describes what he calls a "reverse dominance pyramid", which can be observed in many hunter-gatherer tribes. Individuals who are aggressive, bossy, try to behave like alpha-males are mocked, then warned, shunned, and finally killed or left alone when the tribe moves forward (which also ends with death).

James Woodburn (Egalitarian Societies, James Woodburn, Man, New Series, Vol. 17, No. 3. (Sep., 1982), pp. 431-451. here it is) concludes that all of such societies/tribes are profoundly egalitarian and relationships between people are based on sharing, without any long-term dependencies.  All distinctions – of wealth, power and status – are systematically eliminated.

This could lead to the following answer: there are non-hierarchical cultures, but they are limited to hunter-gatherers. All known human sedentary cultures are hierarchical and there is some leadership in them, as far as I know.

Your question is also problematic, for two reasons. First, leadership and hierarchy are necessarily the same - we can easily imagine human groups in which we can have a voluntary leadership, but which is only ad-hoc and does not depend on any permanent hierarchy. Second, the phrase "culture depending on the concept of x" can also be read in many ways. Your question does not contain it, but the unproven statement that you propose at the beginning does. So be careful in proceeding from an answer to the question to the validation of this statement. You must add something to the mere observation that all cultures have an element of hierarchy in order to establish a fact that they depend on it - we might just observe such correlation in the world. Maybe they were some selection pressures at work at some moment during the last 10k years (warfare?).


What hormones stimulate non-sexual intimate behaviour? From wikipedia article sexual motivation and hormones, it is said that testosterone/estrogen, oxytocin and vasopressin are stimulating sexual behaviour. But I'm wondering if any of these hormones are linked with physically intimate non-sexual behaviour, like hugs, kisses and cuddles. Also, is there any link through them with having pleasure from these activities?

Is there any research on that and are there gender (sex?) differences?

But I'm wondering if any of these hormones are linked with physically intimate non-sexual behaviour, like hugs, kisses and cuddles.

Kissing is a little messy because it could be characterised as sexual behaviour.
However, oxytocin does has a far more broader role in pro-social and affiliative behaviour than just sexual activity.
Here's one reference. It also seems to suggest a stronger role of oxytocin in women than males:

Effects of Partner Support on Resting Oxytocin, Cortisol, Norepinephrine, and Blood Pressure Before and After Warm Partner Contact
Objective: We examined whether the magnitude of plasma oxytocin (OT), norepinephrine (NE), cortisol, and blood pressure (BP) responses before and after a brief episode of warm contact (WC) with the spouse/partner may be related to the strength of perceived partner support.
Methods: Subjects were 38 cohabiting couples (38 men, 38 women) aged 20 to 49 years. All underwent 10 minutes of resting baseline alone, 10 minutes of WC together with their partner, and 10 minutes of postcontact rest alone.
Results: Greater partner support (based on self-report) was related to higher plasma oxytocin in men and women across the protocol before and after WC. In women, higher partner support was correlated with lower systolic blood pressure (SBP) during solitary rest after WC but not before. Also, higher OT in women was linked to lower BP at baseline and to lower NE at all 4 measurements.
Conclusion: Greater partner support is linked to higher OT for both men and women; however, the importance of OT and its potentially cardioprotective effects on sympathetic activity and BP may be greater for women.
ABP = ambulatory blood pressure; BMI = body mass index; BP = blood pressure; CVD = cardiovascular disease; DBP = diastolic blood pressure; HPA = hypothalamic–pituitary–adrenal; HR = heart rate; IV = intravenous; MI = myocardial infarction; NE = norepinephrine; OT = oxytocin; SBP = systolic blood pressure; SNS = sympathetic nervous system; SRI = Social Relationships Index; WC = warm contact.

And another:

More frequent partner hugs and higher oxytocin levels are linked to lower blood pressure and heart rate in premenopausal women
In animals, ventral stroking for >5 days increases oxytocin (OT) activity and decreases blood pressure (BP), but related human studies are few. Thus, relationships between self-reported frequency of partner hugs, plasma OT and BP levels were examined in 59 premenopausal women before and after warm contact with their husbands/partners ending with hugs. Higher baseline OT before partner contact was associated with lower BP and heart rate, and met criteria to be a partial mediator of the lower resting BP shown by women reporting more frequent hugs (P < 0.05). OT levels during post-contact stress were unrelated to hugs or BP. Menstrual cycle phase did not influence any OT measure. Thus, frequent hugs between spouses/partners are associated with lower BP and higher OT levels in premenopausal women; OT-mediated reduction in central adrenergic activity and peripheral effects of OT on the heart and vasculature are pathways to examine in future research.

Also, other transmitter systems are involved in what we might characterise as affectionate behaviour. the opioid system has a role in both humans and non-human primates:
In non-human primates:

Opioid receptor blockade reduces maternal affect and social grooming in rhesus monkeys
Seven lactating female rhesus macaques, housed in social groups, were administered with low doses (0.5 mg/kg) of the opioid antagonist naloxone when their infants were 4, 6, 8, and 10 weeks old. A control group received saline. Mothers receiving naloxone were involved in less grooming with other group members, and were less protective towards their infants. By infant-age week 8 they also groomed their infants less, while other monkeys groomed the infants more. Other behavioural measures of mother-infant interactions were not altered. With time, from infant-age week 6 onwards, some short-lived dysphoric conditioned drug responses to naloxone became apparent, although these were not correlated with the decline in social interaction. These results are interpreted in terms of possible interference of naloxone with maternal affect.

And humans:

Social touch modulates endogenous μ-opioid system activity in humans
In non-human primates, opioid-receptor blockade increases social
grooming, and the endogenous opioid system has therefore been
hypothesized to support maintenance of long-term relationships in
humans as well. Here we tested whether social touch modulates
opioidergic activation in humans using in vivo positron emission
tomography (PET). Eighteen male participants underwent two PET scans
with [11C]carfentanil, a ligand specific to μ-opioid receptors (MOR).
During the social touch scan, the participants lay in the scanner
while their partners caressed their bodies in a non-sexual fashion. In
the baseline scan, participants lay alone in the scanner. Social touch
triggered pleasurable sensations and increased MOR availability in the
thalamus, striatum, and frontal, cingulate, and insular cortices.
Modulation of activity of the opioid system by social touching might
provide a neurochemical mechanism reinforcing social bonds between
humans.