Neurophysiological mappings of empathy What biologically plausible models are there of empathy?

I know there has been a significant amount of work in defining emotion on a neurophysiological basis using models (I'm currently reading "Emotions as semantic pointers: Constructive neural mechanisms" by Thaghard et al. about using the Semantic Pointer Architecture as a basis for emotions). However, I'm having a hard time finding models that define emotions on a neurophysiological basis in relation to other social agents. Do they exist?

When I'm discussing empathy, I'm referring to the phenomena's of affective empathy, cognitive empathy and emotional contagion.

In this answer, I'm going to use "self" to describe the person who is empathizing and "other" as the person who is the target of that empathy (the person who's trying to be related to).

The most advance model of empathy (in terms of affective empathy and emotional contagion) that I know of is featured in "A Recipe for Empathy" by Lim et al. which is based on the idea that mirror neurons provide the body of the "other", the insula which associates the action to the emotional state and the somato-sensory cortex which represents that emotional state in the robot's own state.

She demonstrates the effectiveness of this model by first having a robot learn associations between it's own state and emotions (via motherese-like training), and then seeing if when the robot was exposed to other data, if it had the appropriate response, in terms of classification and internal-mapping. Results showed an adult-like empathy level.

In the paper, Angelica notes that one of the limitations of her model is that it does not address cognitive empathy as Hideki Kozima's model does. I will update this answer with how Hideki does this once I finish reading his paper.

Although both of these models use purely statistical models (Angelica uses Gaussian Mixture Models and Hideki uses) with only vague references to the functionality of various neural areas, they are somewhat biologically plausible, since the computations they are doing are not unfeasible for something like the Neural Engineering Fraemwork to perform.

For further information, I would recommend reading the Handbook of Research on Synthesizing Human Emotion in Intelligent Systems and the Journal on Synthetic Emotion, both which seems to contain further resources for this path of investigation.


What experiment in a simple decision task should we run to obtain one million trials? Context: Models of cognitive processes require very large datasets to be fitted. Sadly, it is difficult for a single laboratory to achieve this alone. I propose that we work collectively and collaboratively in realizing a 1 million RT experiment. This initiative is described on my ResearchGate page, www.researchgate.net/profile/Denis_Cousineau.

Beyond model fitting, such a dataset will be beneficial for other purposes. Examples: Are parameters describing performances normally distributed across subjects? Does training effect --resulting in faster RT-- imply that the parameters are all evolving in one direction? Does Bayesian estimation more apt than Maximum Likelihood at characterizing the parameters? How can we estimate non-decision times? What is the shape of the RT distributions and how training effect alter its shape? In Bayes again, after how many trials does priors have no longer an impact on the estimates? etc.

Task Requirements:
The task must be behavioral only (response times and response choices) as it is not possible to move EEG or fMRI material all around the world. The precise task used is not a critical constraint because the current models of cognition (sampling models such as LBA or Diffusion) are very flexible; they aim at predicting performance in a wide variety of situations.

The tasks proposed will be evaluated based on the following criteria criteria:

small number of response alternatives
few conditions
low error rates
stimuli that can be characterized for modeling purposes
possibility of extended training on that task.

Possible candidate tasks could include: A redundant target detection task (Miller, 1982) or a same-different task (e.g., Bamber, 1969). These tasks are simple and accuracy is typically high (above 90% correct); they are possibly performed using some form of parallel processing; response times are generally well below 700 ms.

So in summary:

What task and experimental design would be most suitable given the above constraints?

Please let's see what are the possible tasks, comment on others' proposals, and if you find the perfect task, upvote it. Have your colleagues make comments or propose new tasks.

I like this idea! I think the task should be one where the data could be used by many analytic tools. Hence, the data would not only be beneficial for one particular question, for example parameter estimations, but also for other tools such as Systems Factorial Technology (see Townsend & Nozawa, 1995), which provides a deeper understanding of the underlying cognitive sub-processes architecture, and other interesting information such as the process' capacity.

I suggest that the task at least respect a double factorial paradigm. This design is very simple: you have four conditions in a 2 x 2 design, where you vary two variables. It could be any variable, the only restriction is that you have to vary them independently one from another. In other words, each variable should reflect a cognitive sub-process. In one condition, both variables are in scenario where the sub-process should work very effectively (or optimally). In an other condition, both variables are in a scenario where the sub-process should work less effectively (or sub-optimally). And in the two remaining conditions, one variable works optimally and the other sub-optimally, and vice-versa.

As for the very details of the task, such as the stimuli that will be used and the specific variables, I do not have preferences. Letters are very manipulable, but they do carry semantic (more or less). Abstract stimuli could work. We could play with color, shapes, complexity, etc. At Psychonomics this year, they were many experiments which have use this design.

Reference for citation:
Townsend, J. T. & Nozawa, G. (1995). Spatio-temporal properties of elementation perception an investigation of parallel, serial, and coactive theories. Journal of Mathematical Psychology, 39(4), 321–359. doi: 10.1006/jmps.1995.1033


Standardised test to measure workplace stress I'm trying to find a standardised test that is used to measure stress in the workplace. So far I've found Copenhagen Psychosocial Questionnaire - COPSOQ II, which looks good. But I want to see what other options there are, or if there are any known major problems with COPSOQ II. Equally even the short version of COPSOQ II is arguably too long for what I want to use it for, so shorter suggestions would be greatly appreciated too.

Although it is not exactly stress, there are many self-rating scales for workload. The most popular one is the NASA-Task Load Index (NASA-TLX; Hart & Staveland, 1988; see also here). The NASA-TLX consists of six dimensions, which a.o. describe temporal demands, mental effort and frustration. Although there is some weighting procedure accompanied with it, you can just sum the scores of each dimension to get a general workload score.

Another popular scale is the rating scale mental effort (RSME; Zijlstra, 1993). This scale is one-dimensional and is responded to by marking a cross on a line. The scale ranges from 0 to 150 and is marked with anchors points at uneven intervals.

Last one I know is the Integrated Workload Scale (IWS; Pickup et al. 2005). This scale consists of nine items which describe a particular degree of workload ranging from "not demanding" to "work too demanding". The scale acknowledges that workload is influenced by several dimension and, therefore, the items do describe several dimensions, such as mental effort and temporal demands. The scale has been developed for train traffic controllers but a validation study suggests that it can be used in different languages and in many other domains (Kramer, Johnson & Zeilstra, 2015).

The benefit of the RSME and the IWS is that they can easily be used during the task, since the rating procedure it rather simple and short. Of course, there are also several physiological (e.g. skin conductance, HRV) and performance measures (e.g. RT to a secondary task). For a comparison please refer to Brookhuis & De Waard (2001).


How to explain utility function from personality, beliefs and ongoing emotions? Economists widely use utility function (and more broader approach called hedonistic regression) but are there explanations or derivations of utility function from the perspective of cognitive sciences or psychology which can take into account personality, beliefs and experience (memory) and ongoing emotions (affects)? Clearly one should start with the Maslov pyramid that determines goals and needs and then one can proceed to explain why different people value differently one and the same goods or services? Are there such research trends, some keywords, terms, notable researchers in this area?

I have read only about incorporation of altruism in the utility function of neoclassical economics, about hypberbolic discount function and so on. But I have not managed to find more practical explanation of utility function.

This question has the following context: I am trying to model the economic behavior or BDI agent - agent with Beliefs/Desires/Intentions. BDI is the most popular approach for modelling cognitive agents. Recent research (e.g. http://people.idsia.ch/~steunebrink/) has endowed BDI agents with formalization of emotions (KARO logic framework) and there is scarce but ongoing work to endow BDI agents with personality (e.g IEEE Transactions on Affective Computing and Five Factor Model from personality psychology). So, BDI agents have cognition, personality and affects and they can be used as models of human economic behavior. But there is missing link from economics and cognitive sciences - how humans act as economic agents? What are the models? What goals they can have, how behavior (decision to make purchase) can be infered from agent's goals, beliefs, personality and emotions? How human perception of utility (of particular attributes of particular products, particular designs, particular type of entertainment, etc.) is connected with his personality, experience, beliefs, affects? Utility function seems to be promising proxy in this research - psychology can explain utility function and economics can apply this function to particular transactions.

Is there some research along this lines?

This should be promising area of research. Because common approach to economic analysis and prediction is connected with Data Science and statistical methods (conjoint analysis and hedonic regression). What I am trying to do is to find logic, semantic, cognitive methods of explanation and prediction of customer behavior. Similar trend - from statistical to semantic methods can be found in other fields of Science as well - e.g. in natural language processing, in search engine engineering and so on.

How to integrate realistic cognitive models of human behaviour and ecomonic models is an open research question, however to tackle it, it might be helpful to break it into a few more easily answerable sub-questions:

What models of human planning with emotional influence exist? There are a number of models in existence that try to capture emotion and personality. However, I don't know any that apply to planning specifically, given that modelling long-term planning is an extremely hard problem in it's own right! My lab-mate Peter Blouw made a rudimentary model of planning with Bryan Tripp that just got accepted to the CogSci2016 Conference. I will update this answer with the link once it is public ally available.
What models of human social interactions integrate personality? Human social interactions are really hard to model, especially at a large scale, consequently most models that currently exist are rudimentary at best.
What is the most detailed cognitive model of human behaviour used in economics? I don't know the answer to this off the top of my head, by I remember this being discussed in Khaneman's "Think Fast, Thinking Slow", where he talks about the diminishing returns that come with including more complicated cognitive factors in economic models.

To get more complete answers to these questions, feel free to ask them as separate questions on this site. I will happily upvote them!


What introductory material is available linking complexity theory to cognitive science? Does complexity theory speak to cognitive science?
If yes, where can I find some material to explore that is suitable for undergraduate level understanding?
In particular, is there any audio contennt on this?

In general, there are two types of 'complexity' that are studied. Usually, when people talk about 'complexity', especially on the internet, they mean Santa Fe Institute style complexity. This is a vague and poorly defined concept that has struggled for a number of years without making significant progress. It uses pretty words, but has yet to deliver on any real results. I will not discuss it more in this answer.

The other type of complexity is computational complexity theory as studied by theoretical computer science. In general, this field is too mathematical and too rigorous to engage with most of cognitive science and psychology, but there are a few connections. I recommend looking at the cstheory question: What is the complexity class most closely associated with what the human mind can accomplish quickly?

In that question, the author is curious to know which complexity class most closely resembles what humans can achieve. My favourite answer discusses the Tractable Cognition thesis. For reference, see these papers:

Iris van Rooij. The Tractable Cognition thesis. Cognitive Science, 32, pp. 939-984, 2008.
Iris van Rooij. Parameters that make Cognitive Work Light. FPT News: Parameterized Complexity Newsletter, June 2009.

A specialized part of computational complexity known as computational learning theory has been particularily notable in trying to make connections to cognitive science, in particular linguists. Gold's theorem on the non-learnability of certain families of formal languages was especially relevant in the early days of the poverty of the stimulus debate. You can learn more about it in these two questions:

Applications of computational learning theory in the cognitive sciences
General mathematical frameworks of language acquisition since Gold

Keep in mind, that computational complexity is advanced material and requires a decent mathematical sophistication. However, with difficulty comes insights.


What's the difference between injunctive norms and descriptive norms? I can't seem to understand the difference. From wikipedia

  Injunctive norms involve perceptions of which behaviors are typically
  approved or disapproved They assist an individual in determining what
  is acceptable and unacceptable social behavior. This would be the
  morals of your interpersonal networks and surrounding community .
  Descriptive norms involve perceptions of which behaviors are typically
  performed They normally refer to the perception of others' behavior.

The distinction stems from research on the "Focus Theory of Normative Conduct" (e.g., Cialdini et al. 1990)

Injunctive norms refer to the perception of what ought to be, or as you state, perceptions of what is approved or disapproved by others.

Example: If you think that other people would consider tax fraud as something that is morally wrong, you would perceive an injunctive norm.

Descriptive norms refer to the perception of what is. Or, in other words, perceptions about how people do in fact behave.

Example: If you think that most people engage in tax fraud, that would be a descriptive norm.

As you can see, injunctive and descriptive norms are distinct concepts. Sometimes they may overlap (tax fraud is wrong, and nobody does it). However they may also conflict (tax fraud is perceived to be wrong, but everyone does it). Of course they can also be about positive things (it's a good thing to eat 5 portions of veggies each day vs. nobody does that).

Reference

Cialdini, R. B., Reno, R. R., & Kallgren, C. A. (1990). A focus theory of normative conduct: Recycling the concept of norms to reduce littering in public places. Journal of Personality and Social Psychology, 58, 1015–1026. doi:10.1037/0022-3514.58.6.1015


How exactly does transcranial direct current stimulation (tDCS) work? The method of transcranial direct current stimulation (tDCS) involves the flow of electric charge from a positive electrode to a negative one.

This method is not exactly a stimulation method because the current applied do not provoke neurons firing such as TMS (transcranial magnetic stimulation), it just modulate the level of excitability of neurons. How happens this modulation of excitability?

Precisely, my question is:

How that positive or negative current interferes with electric fields generated by neurons?

references:

Impact of Transcranial Direct Current Stimulation (tDCS) on Neuronal Functions

I'm not sure at what level of sophistication you expect this answer, but the basic theory of how tDCS works at a cellular level is that neurons oriented roughly parallel to the electric field lines suffer a (partial) depolarization of the axon hillock cell membrane when the dendrites of the neuron are oriented toward the anode of a constant electric field, and the a reverse effect (hillock membrane hyperpolarization) occurs when the dendrites are oriented toward the cathode. (Niedermeyer's Electroencephalography, 6th ed., p. 1136) And on this basic theory, not much happens if the neuron is perpendicular to the electric field. Another way of saying the same thing (but more concisely) from Lefaucheur et al.:

  The primary effect of tDCS on neurons is a subthreshold shift of resting membrane potentials towards depolarization or hyperpolarization, depending on current flow direction relative to axonal orientation.

The simple theory above applies to a cell in isolation. I'm even less sure I understand your detail question "How that positive or negative current interferes with electric fields generated by neurons?" In more sophisticated approaches, the cell shapes also affect the electric field influencing nearby cells; see for instance Ye & Steiger. Ultimately, in a nonhomogenous medium like the brain, it's quite nontrivial to determine the local electric field orientation induced by some distant electrodes. To get a solution one needs to simulate the entire brain as done by Wagner et al. for instance.

To verify that tDCS basically works like this (i.e. as a modulation, as you correctly observed) one can experimentally add another stimulus that can trigger neuronal activation, for instance TMS, and measure how much of this extra stimulus is required to obtain the same effect with and without tDCS. This was done for instance in the highly-cited study of Nitsche and Paulus. They observed excitability changes of up to 40% using this method.

The basic theory doesn't quite explain everything relating to tDCS, in particular it doesn't explain why some effects persists for a time after the DC current is turned off; the extent of these effects is dependent on the current intensity and the duration of the stimulation. Nitsche and Paulus discuss some theories relating to this, mentioning that perhaps tDCS induces changes in the spontaneous discharge rate as well.


Examples of interventions that yield large long term effect sizes in psychology I was listening to a podcast entitled Very Bad Wizards, hosted by two university academics.  One of the hosts, namely David Pizarro who is a psychologist at Cornell made the claim that most psychological mechanisms have small effects.  I have heard this too mentioned by Daniel Lakens on the small likelihood of psychological effects being very large > d =1.6.  That made me curious.  What are examples of interventions in Psychology that reliably induce long and large changes (large effects that last longer than ~3 months)?  The only example that comes to mind are mood states like trait anxiety being changed nearly indefinitely through CBT with pretty big effects.  A little background, I was a Psychology major and researcher in undergrad.  Enjoy reading about meta research so I can go pretty technical.

Skill acquisition: If you take a novice on a task and get them to practice that task, performance will tend to improve. See the Power Law of Practice. In many cases that I've seen, the difference between between initial and final performance is similar to the standard deviation of individual differences at baseline. So I guess you could call that a d of around 1. Of course, the exact numbers will depend on the domain, but that is indicative.

Of course, you also get forgetting effects which in some sense reduce the effect of skill acquisition over time, but there is also an associated faster relearning effect. And the degree of forgetting is related to a range of factors. In particular, motor-learning seems to have less forgetting than learning related to declarative facts.


Does psychology have a name for the "click" experienced in mathematics? To understand what I mean, for three days I stared at a formula that looked Greek. Its semantics of relationship was unknown. The mathematics was just one long blur without logic and making no sense. I came back and forth to it. Then one day it was like a veil was lifted over my head and everything "clicked" and made sense.

I remember some of the best mathematics advice I received was "sometimes things click with repeated exposure and this happens a lot in mathematics." I never paid attention to this until I learned to appreciate this "click" phenomenon which I would like study in a more scientific manner but don't know the term(s) I should be looking for.

Thus why I'm here:

is there even a name for this "click" experience in mathematics?

There is a name for Déjà vu which even is studied, but what about the "click"?

There are concepts like insight and the Aha moment which are similar to what you describe.

However, the aha moment is more aligned to flashes of insight to discrete problems. While this could be relevant to the experience you are describing of learning mathematics, perhaps you are also describing a more gradual process of learning. Mathematics can be quite complicated. With each iteration of practice, reflection and consolidation, an you typically learn more. At first you made need to go through the material just to get an organising framework. Then on  a second read, you can start to apply the organising framework to your interpretation. The meaning of the text and symbols begin to be stored in long term memory, so you can start to focus on the broader meaning rather than spending substantial cognitive resources on the components.

So in general, what you are describing sounds a lot like the process of cognitive skill acquisition. If you want to learn more you could read something like Anderson (1982). Basically, this is a movement from effortful and error prone performance to fluent and relatively error free performance. Thus, at a certain point, you reflect on your performance and you realise that you have acquired the skill.

References

Anderson, J. R. (1982). Acquisition of cognitive skill. Psychological review, 89(4), 369-406. PDF


What causes lack of energy? The relative importance of testosterone versus emotional, genetic, and environmental factors Some people assume that males lack of energy because of low testosterone.
I would think that lack of energy could be due to esteem levels, emotional abuse, low self-worth, and even genetics to some point.

What is the relative importance of testosterone versus  environmental, genetic, and emotional problems in causing lack of energy?

This question hits home for me quite a bit.  But, I'd have to say about half or more of the population has energy problems otherwise people wouldn't be chugging coffee.

I'll simply cite my own anecdotal experience with this as I've tried so, so many things to increase my energy levels - one of them being testosterone.

I tested relatively low (not that low though - I believe 300-500 mg/dl if that's the measurement) for testosterone from a blood test which I had done out of curiosity.  So I went to an open minded (later realized VERY open minded) endocrinologist in the area and after some discussion he prescribed me testosterone propionate, which hits you in about 3-4 days time.  It was a very strong dose and worked very quickly. It's pretty much the quickest way to artificially get testosterone into your body via intramuscular injection - I believe.  I guess we came to the agreement that we may as well see if it helps or not as quick as possible - won't hurt anything....

So I took it.  For about 4 weeks.  I actually didn't feel any different energy wise, "masculine" wise, feel any angrier, feel any increase in libido, or actually feel anything from it whatsoever.   The only things that happened were:

1)  I gained a ton of water weight - which went away when I stopped.  It was about 30 pounds worth.  Probably a mixture of muscle and water actually.
2)  I had a puffy face for a few months.
3)  My bench went up by about 30 pounds in 2 weeks which was pretty cool.  This obviously went away  afterwards though.  (I wasn't really trying that hard to get ripped...just do an experiment).
4)  That's about it.

Now, you may question if you had the real stuff just as I did.  Well, my bench obviously went up and I was gaining water weight....but here's the stranger part:

As my finances were horrible at that time I couldn't see the endocrinologist again - and really he had given me the most powerful testosterone treatment possible.  I'm not sure how he got away with it.  I managed to snag one of those at home saliva tests that you freeze and Fedex next day to a lab though.  Just cause I wanted to see what my results would be.

The lab must have made a mistake or something - but the lab literally came back with a report that my testosterone levels were ~"50,000 mg/dl." This would be about a 100 fold increase in my testosterone levels.  The funniest part was at the bottom of the report it just had a generic line saying to "seek the advice of an endocrinologist."  I think that's like the lethal dose of testosterone, lol.

Regardless, you'd have to admit I did have alot of testosterone in my body, even if it wasn't that much.  After that though, if I was presumably "HE MAN" and I didn't have more energy or feel much different I didn't see a point.

I didn't really follow up with it much after that.  Nor did I have the money to see that endocrinologist again.

Also there's ALOT more factors than the ones you listed like motivation, nutrition, length of sleep, depth of sleep, dopamine as well as several other chemicals in your brain, etc...

In this example though, keep in mind the n=1, and someone else may respond completely differently.

I think someone wanted studies.  I found some interesting ones....

  Beyond masculinity: Testosterone, gender/sex, and human social behavior in a comparative context. van Anders SM. Source Departments
  of Psychology & Women's Studies, Programs in Neuroscience,
  Reproductive Sciences, and Science, Technology, & Society, University
  of Michigan, USA. Electronic address: smva@umich.edu. Front
  Neuroendocrinol. 2013 Aug;34(3):198-210. doi:
  10.1016/j.yfrne.2013.07.001. Epub 2013 Jul 16.
   Abstract  Largely based on pre-theory that ties high testosterone (T) to
  masculinity, and low T to femininity, high T is mainly studied in
  relation to aggression, mating, sexuality, and challenge, and low T
  with parenting. Evidence, however, fails to support this, and the
  social variability in T is better accounted for by a
  competition-nurturance trade-off as per the Steroid/Peptide Theory of
  Social Bonds (van Anders et al., 2011). Four key domains are
  discussed: adult-infant interactions, sexual desire, sexual behavior,
  and partnering. Empirical engagements with gender/sex are shown to
  lead to important insights over assumptions about
  masculinity-femininity. Humans are discussed within a comparative
  framework that attends to cross-species principles informed by human
  insights alongside human-specific particularities like social
  constructions, which are critical to evolutionary understandings of
  the social role of T. This paper thus integrates seemingly orthogonal
  perspectives to allow for transformative approaches to an
  empirically-supported social phenomenology of T.

Now in this one they are trying to make clear that the levels of testosterone are not the REAL dependent variable, but actually the interaction of it with something they call "competition-nurturance trade-off as per the Steroid/Peptide Theory of Social Bonds".  T and this variable could be correlated.  I'm not sure yet...so lets go find out what this theory is.

I did find many other studies that just simply relate aggression (and yes I know your question is more about energy), but the problem with them is they tend to admit they're able to flip the x's and the y's.  They don't know which influences the other.  Does an angry type of person usually take steroids more often?  There's alot of questions like those.  I can discuss them if you guys want me to, but this is way cooler:

.....and BOOOOOOM.....if you ever wanted to know anything about Testosterone I'd ask van Anders here.

  The Steroid/Peptide Theory of Social Bonds: integrating testosterone and peptide responses for classifying social behavioral contexts.
  van Anders SM, Goldey KL, Kuo PX. Source Department of Psychology,
  University of Michigan, 530 Church Street, Ann Arbor, MI 48109, USA.
  smva@umich.edu

  Hormones, and hormone responses to social contexts, are the proximate
  mechanisms of evolutionary pathways to pair bonds and other social
  bonds. Testosterone (T) is implicated in tradeoffs relevant to pair
  bonding, and oxytocin (OT) and arginine vasopressin (AVP) are
  positively tied to social bonding in a variety of species. Here, we
  present the Steroid/Peptide Theory of Social Bonds (S/P Theory), which
  integrates T and peptides to provide a model, set of predictions, and
  classification system for social behavioral contexts related to social
  bonds. The S/P Theory also resolves several paradoxes apparent in the
  literature on social bonds and hormones: the Offspring Defense
  Paradox, Aggression Paradox, and Intimacy Paradox. In the S/P Theory,
  we partition aggression into antagonistic and protective aggression,
  which both increase T but exert distinct effects on AVP and thus
  social bonds. Similarly, we partition intimacy into sexual and
  nurturant intimacy, both of which increase OT and facilitate social
  bonds, but exert distinct effects on T. We describe the utility of the
  S/P Theory for classifying 'tricky' behavioral contexts on the basis
  of their hormonal responses using partner cuddling, a behavior which
  is assumed to be nurturant but increases T, as a test case of the S/P
  Theory. The S/P Theory provides a comparative basis for
  conceptualizing and testing evolved hormonal pathways to pair bonds
  with attention to species, context, and gender/sex specificities and
  convergences.

So it looks like this guy may have even made a formula or algorithm for determining the social outcome - he also mentions several paradoxes that occur with T - ones you'd see in the literature.  He also granularly separates things - for instance we he "partitions antagonistic and protective aggression" and also notes the hormonal responses to each situation.  Unlike many others, I enjoy how he factors in the other obvious dependent variables instead of just drawing a line that represents, linearly, testosterone = angry.  Or, y(whatever it may be) = testosterone*x

If you go along with this theory then you'd realize that it's not just the testosterone that would make someone angry or even irritable (in fact it may only be an indirect cause) - it's the relationship between testosterone and other things that cause that or someone to feel a certain way.

Now I know you are more interested in energy, and that could be applied here, but it also fits right into your question because it essentially says that it is the relationship between those variables that may account for it.

Sometimes in statistics your "independent" variables don't mean much of anything (if say you're trying to find the best model for a regression) until you realize that the relationship between them (if you can figure it out) has a huge affect on the Y.

Let me get straight to your question:

  What is the relative importance of testosterone versus environmental, genetic, and emotional problems in causing lack of energy?

-So I obviously have an anecdotal opinion in that it didn't do much for me.

-But, as I stated earlier in the post, I think you are missing a ton of other variables like nutrition, workout habits, relationships, willpower (interesting question - do you choose your own willpower?), how much you like your job, etc. - unless you are lumping those together in environmental, which I feel would cause one's view of their influence to be quite skewed.

-Even though T obviously plays a role in advanced physiological processes in your body just like van Anders talks about, I believe and the research seems to suggest (as well as just general fact) it's importance increases as the amount you have below the mean for your age/gender/genetics decreases.  Here's a case study for instance: http://www.ncbi.nlm.nih.gov/pubmed/11675582

In essence, probably what happened to me was I didn't actually have low T and that's why I didn't feel much different.  Even bodybuilders who take that stuff say it's only 10% of the process.  I'd imagine the curve to look generally logarithmic in as far as I suppose it making you feel different - and everyone's initial y intercept (if we say there is one) is going to be at a different place.  If someone genuinely thinks they're really low, they might be.  If so, I recommend asking one's doctor about a "Taal Test." It could do nothing for that person or they could feel alot different - see the link I provided.

It's the same thing with almost any disorder or disease though...the doctors usually just make their best guess and try out a bunch of stuff on you until something sticks.  Except, unfortunately, they don't do much research first and are either

  a) persuaded by the patient that is persuaded by big pharma b)
  persuaded directly by big pharma  c) won't listen to you until you
  do crazy stuff like bring in research papers like I do sometimes.
  d) have huge egos e) even then, when do they have time to do any
  real updated research?

Finding a good doctor, in my opinion, is about learning how to heal yourself first.


Can we smell in dreams? I'm interested in whether people can smell in their dreams.
Do people really experience smell in their dreams?
For example, if I dream of smelling a flower, will I feel the smell, too?

Is there any research on whether people can smell in dreams?

Antonio, Nielsen and Doneri (1998) provide one assessment of self-reported  prevalence of smell in dreams. To quote the abstract (my bolding):

  Although numerous studies have investigated the content of
  laboratory  and home dream reports, surprisingly little  is  known
  about the prevalence of various sensory modes in  dreams. 49 men and
  115 women completed a battery of questionnaires and kept a home dream
  diary for two to three consecutive weeks. Retrospective responses to
  the questionnaire indicate that  approximately  33 %  of  men and 40%
  of  women recalled having experienced sensations of  smell  or taste in
  their dreams. A  total  of  3372 dream reports were collected and
  scored for  unambiguous references to  auditory,  olfactory,  and
  gustatory experiences. Auditory  experiences were reported in
  approximately  53%  of  all  dream reports. Olfactory  and gustatory
  sensations occurred in  approximatdy 1 % of all dream reports. A
  significantly greater percentage of women than men reported one or
  more dreams containing references to olfactory sensations. The results
  lend support to  previous studies which have shown that a variety of
  sensory experiences, although relatively  rare, can occur in dreams.

There is still the question about whether self-reports are trustworthy, and how you define a smell experience in a dream that is most likely not generated by external stimuli. Antonio and colleagues go on to discuss some of these issues:

  That  the more infrequent modalities of  smell and taste occur at all
  in dream reports is an important indication of the representational
  capacities of dreaming-and  probably of  imagery more generally. The
  finding  is consistent with  recent research showing the existence of
  imagery in both olfactory (Carrasco &  Ridout, 1997; Lyman & McDaniel,
  1986) and gustatory (Drummond,  1995) modalities. Although  some
  researchers take the position that olfactory imagery is not possible
  (Herz & Engen, 1996), the spontaneous occurrence of olfactory imagery
  in  dreams may differ  from "willful"  olfactory imagery that may
  occur upon instruction during  the waking state. For  instance, limbic
  structures which  might  yield  such spontaneous occurrences during
  dreams may not be operational during the waking state. Nevertheless,
  it  is  likely  that  the  relatively rare occurrence of  these
  modalities during dreaming is not  because their  representation is
  beyond imaginal capacity. Rather, either such sensations are not
  usually spontaneously  generated during dreaming, i.e., are not a
  necessary component of dreaming's supposed memory/adaptational
  functions, or they depend upon external sensory stimuli to trigger
  them. However, sensory triggers may be selectively blocked at  the
  thalamic level by the raised afferent thresholds of REM sleep (e.g.,
  Steriade, 1994). Of  course, both  of  these inhibiting  conditions
  may be true, thereby seriously disfavoring appearance of gustatory or
  olfactory sensations during dreaming

References

ANTONIO, L.Z. and Nielsen, T.A. and Donderi, DC. (1998). Prevalence of auditory, olfactory, and gustatory experiences in home dreams. Perceptual and motor skills, 87, 3, 819-826.PDF
Carrasco,  M.,  & Ridout,  J. B. (1997)  Olfactory perception and olfactory imagery: a multidimensional analysis. Journal  0f Experimental Psychology: Human Perception &  Performance,
19,287-30l.
Drummond,  P. D. (1995)  Effect of imagining and actually tasting a sour taste on one side of the tongue. Physiology & Behavior, 57, 373-376.
Herz, R. S, & Engen,  T. (1996)  Odor memory: review and analysis. Psychonomic Bulletin & Review, 3, 300-313
Lyman, B. J., & McDaniel. M. A. (1986)  Effects  of  encoding  strategy  on  long-term  memory  for
odours. Human memory. Quarterly Journal of Experimental  Psychology: A-Human  Experimental Psychology, 38(4-A), 753-765.
Steriade,  M.  (1994)  Brain electrical  activity and sensory processing during waking and sleep states. In  M.  H. Kryger, T. Roth, &  W. C. Dement (Eds.), Principles and practice of sleep medicine. (2nd ed.) Philadelphia, FA: Saunders. pp.  105-124.


What is a good measure of self-regulation? Is there self-regulation or self monitoring test. I am interested in measuring why people are not commited to their goals (quit smoking, dieting etc) so you can suggest another measure instead of self-regulation failure.

You can also use a stop signal task that measure response inhibition. It has been associated with dependencies like smoking http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3077266/ and http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0018898 for a go/nogo task, though the stop signal task is preferred. There is also some studies linking inhibtion to self regulation and self control, although I dont remember the sources at the moment. Sorry for poor formatting, new here at s.e.


What are the underlying mechanisms for optimism bias? I have asked a question before about how does smoker's decision react to new personal health information. Link here.
 How do people estimate smoking's impact on their mortality?

Now I have a follow up question. Psychologists have termed smokers's over confidence about their chance of not being hurt by smoking as optimism bias. My question is: has there been any neuroscience, medical or psychology research about the mechanisms of optimism bias?

Optimism bias refers to a general human tendency to underestimate the likelihood of negative events, and conversely, to overestimate the likelihood of positive events, when making predictions about which events will occur to oneself in the future.

It is a cognitively interesting and widely studied phenomenon, because the human brain and human behavior are broadly believed to be highly adaptive, but optimism bias demonstrates that in many cases, we maintain beliefs in spite of the available evidence. This is a somewhat less surprising finding nowadays, since modern psychology has largely abandoned the idea of humans as rational actors. There was a time, though―a time, in Skinner's heyday, when optimism bias was considered baffling and proper paradoxical.

Sharot (2011) suggested that optimism bias is cognitively maintained by a bias towards updating our beliefs in response to positive prospective information than to negative prospective information. She attributed this to decreased encoding of negative-update information in the right inferior frontal gyrus. In another paper, Sharot, Riccardi, Raio and Phelps (2007) had reported this decreased encoding may be mediated by activity in the rostral anterior cingulate cortex (rACC) and amygdala:

  Here we report that [optimism bias] was related specifically to enhanced activation in the amygdala and in the rostral anterior cingulate cortex when imagining positive future events relative to negative ones, suggesting a key role for areas involved in monitoring emotional salience in mediating the optimism bias.

In other words, the amygdala appears to evaluate the emotion valence of the information, evoking a regulatory response in the rACC, which is implemented as an inhibited update to negative-update evidence, or optimism bias, by the right inferior frontal gyrus.

References

Sharot, T. (2011). The optimism bias. Current Biology, 21(23), R941-R945.
Sharot, T., Riccardi, A. M., Raio, C. M., & Phelps, E. A. (2007). Neural mechanisms mediating optimism bias. Nature, 450(7166), 102-105.


Is it appropriate to do a study using only one trait from a larger personality inventory (e.g., Extraversion)? I'm looking to gather peer reports and self reports of extraversion. Can I send out an item inventory that only has extraversion related items?

Yes. It is quite common to do a study that measures just one personality trait. There are many variations in this and reasons for doing this. Here are some examples:

You measure the Big 5, but you want to incorporate some other personality trait not captured as well by the big 5 (e.g., honesty/humility from HEXACO; dark triad, etc.)
Personality is a minor component of the study, so you just measure the one or two dimensions of interest.
You are specifically interested in the facets of a particular dimension so for example, you measure conscientiousness as well as many different facet scales of conscientiousness.

In these cases, items are often taken from a larger inventory. E.g., you take just the extraversion items from a measure of Big 5.

There are legitimate reasons for why you might want to only measure one personality trait. That said, if length is not a major issue, I would strongly encourage you to measure a broader set of traits. In particular, there are many benefits to getting a complete measure of the Big 5 (or perhaps HEXACO). You can then examine correlations in context and provide a much more complete picture.


What is the difference between (and importance of) extrinsic vs. intrinsic rewards in gamification? What is the definition  of extrinsic and intrinsic rewards?

Why are they important to, and what is their role in, gamification?

Intrinsic Rewards (motivation)
These are rewards which are directly of value to the person, rather being something that represents (or could be "traded in") for something to of value.

So getting a badge in and of itself isn't an Intrinsic Reward, but up votes on an answer would be b/c it converts Status and Validation of the user's work.
These rewards are also intrinsic to the task. They have not been "bolted on" or "dangled like a carrot" in front of the user.

Extrinsic Rewards (or incentives) are rewards which  are not naturally a part of the task.
So if you enjoy drawing and I compliment you on the drawing that's intrinsica. If I offer to pay you to draw more, that's extrinsic.

from this slideshow.

Extrinsic Incentives are demotivating and, thus, should be avoided in Gamifying a system
There is a lot of research that shows that Extrinsic Rewards are demotivating because:
They extinguish internal motivation

Result in Habituation, requiring higher levels of the External reward
to achieve the same effects.
Send a message that you think they should not want to do this (why
else would you need to bribe them)
Seem manipulative

Therefore, Extrinsic Rewards should be avoided.
And if you find that your "players" are focused more on the game mechanics than the work then that's a clue that your game mechanics may be offering extrinsic motivation.


What are the meanings of the word 'gender'? Gender is often loosely described as the psychological parallel of sex. But this is more like a simile than a description. It is also often noted as being in the mind e.g. the genderbread man.

When you look for a more complete description results vary. It is sometimes described as:

A person's expectation of their physical sex. This implies that we know in our heads what our secondary sexual characteristics ought to be, in the same way that we have an awareness of where our arms and legs are. This relates strongly to gender dysphoria. Under this definition of gender transgender people are defined by their feelings of gender dysphoria, which is to feel that your secondary sexual characteristics are somehow incorrect.
Gender is also sometimes described as a personality label. Under this definition we associate different genders with different averaged personality. No real personality exactly fits a gender, but like the difference between a feminine face and a masculine face we identify ourselves by that which we are closer to. So for example having a larger nose is generally a masculine face trait but there would still be predominantly female faces with large noses, just as attention to detail is predominantly a female trait but there will still be male personalities that incorporate high attention to detail.
Gender is also described as a set of socially constructed roles. There are behavior patterns and activities that are associated with different genders. The behavior of an individual defines their gender. This would make gender entirely a social construct.

This is probably not a complete list. I also suspect that multiple items might be 'true' (or perhaps useful is a better word) simultaneously. The word gender clearly has many different meanings to different people. I would like to know what meanings are out there and who uses each meaning. Please feel free to only add one definition.

According to the American Academy of Pediatrics the following is stated:

Sex is a biological construct, what is real:
Attributes that characterize biological maleness and femaleness including:
Chromosomes
Hormones
Anatomy

Gender is a social construct, or 'man-made':
Attitudes and feelings that a given culture associates with a persons biological sex such as:
Gender expression
Gender roles and behavioirs
Gender identity
This Varies by time and culture

I am not able to identify to what degree the AAP's views are accepted or rejected by other organizations.

Source:
PDF, slide 7, from the AAP

Reference (Best attempt available for now)

Garofalo, R. (2013). Understanding Gender Nonconformity in Childhood and Adolescence
Webinar Video: https://www.aamc.org/initiatives/diversity/449804/aap2.html
Free Original Source PDF: https://www.aap.org/en-us/Documents/solgbt_webinar_transition_garofalo.pdf
Source PDF Bibliography [Free PDF]: http://www.pedsuniversity.org/Portals/2/biblios/Garofalo_Gender_biblio.pdf


Articles about model of eye movements and trajectories I need to work with data from an eye tracker. I have raw data about eye coordinates. I need to reconstruct trajectories of eye movements. Since I know modern science has several methods for this task, I already googled for them, but I don't know which ones are serious and authority works.

I am not sure what you may have looked up previously, but here are a couple of referenced articles that may be of help to you:
"Identifying Fixations and Saccades in
Eye-Tracking Protocols" (Salvucci and Goldberg, 2000), from their abstract:

  In this paper we propose a taxonomy of fixation identification
  algorithms that classifies algorithms in terms of how they
  utilize spatial and temporal information in eye-tracking
  protocols.

In terms of Human-computer interaction:

"Commentary on Section 4. Eye tracking in human-computer interaction and
usability research: Ready to deliver the promises." (Jacob and Karn), this article makes reference to several more specific references.


What is the meaning of “the inner leaflet of their lipid bilayer corresponds to the outer leaflet of the plasmalemma.” The whole quote is, “Their lumen corresponds topologically to the outside of the cell; consequently, the inner leaflet of their lipid bilayer corresponds to the outer leaflet of the plasmalemma.” The “they” corresponds fo the vacuolar apparatus of a cell. My question here is, how is it possible for the inner leaflet of the vacuolar apparatus to lie on the outer leaflets of the plasma membrane? Wouldn’t this mean that the vacuolar apparatus partly lies outsides the cell? Or am I mistaken? The excerpt is from Chapter 4 of Principles of Neural Science by Kandel et al.

I don't have Kandel in front of me but I am pretty sure I know what your book is trying to say. The specific language they've chosen for this section is quite odd and I believe old-fashioned, though, which might be leading to your confusion.

Transferring membrane-bound material from intracellular organelles to the surface of a cell involves or vice-versa involves fusing vesicles with the plasma membrane or budding vesicles from the plasma membrane. The process is more or less the same, just in reverse. See the diagram below:

Adapted from https://en.wikipedia.org/wiki/Golgi_apparatus#/media/File:0314_Golgi_Apparatus.jpg
Notice how the "protein" has its purple plus-shaped domain on the outside of the cellular membrane? If it were to be secreted in a vesicle (as pictured here) or taken up by endocytosis (just imagine the arrows pointing the other way), fusing or pinching the membrane would mean that this "outside" part is actually on the inside of the secretory vesicle, Golgi apparatus, any lysosome/endosome, etc. What stays constant is the part facing the cytosol.
Therefore, you can say that the "inside" of any of these compartments "looks like" the outside of the cell, whereas the outside of these compartments (facing the cytosol) looks like the inside of the cell membrane (also facing the cytosol).
For another intuitive way of thinking about this, imagine you have an inflated balloon. You press a marble into the side of the balloon and pinch inside so now the marble is entirely inside this little bubble inside the whole balloon. It's still covered by "outside balloon", but yet it is inside this little compartment you've created.
For more general thoughts on "topology" (what is referred to by "topologically") see the general mathematical concept: https://en.wikipedia.org/wiki/Topology


What is the difference between hypnosis and meditation? It seems that many people say that hypnosis and meditation are very similar. But what are their key differences (both in a soft and hard way)?

I believe this question is impossible to "answer" because the inherent premises in the question are based on the assumption that there are two discrete dichotomous phenomena, "hypnotism," and "meditation," which can somehow be meaningfully "defined," and, then, "compared."

Both "hypnosis" and "meditation" are figuratively vast conceptual collages of imprecise multiple-meanings, observations of what appear to be "special" states of human awareness, and consciousness, admixtures from what in "western science" is termed "psychology" with an equally vast mix of practices, lumped-together as "spiritual," from the world's religions, etc.

From the viewpoint of epiphenomenal philosophy ... wikipedia entry ..., and from some modern, western, theorists of human consciousness as grounded in our biological, neurological, reality, both hypnosis and meditation can be regarded as secondary phenomena: in the sense that they are culturally defined and shaped modes of thought, behavior, and experience, in a "continuum of consciousness," which, over time, are conserved, institutionalized, even valorised into being perceived as "sacred."

In Vipassana meditation, in the Theravadan Buddhist tradition (Sanskrit "sthaviravada," "teachings of the elders") one way the "anti-goal" of meditation could be defined is: it is a practice meant as a vehicle for the de-hypnosis of the "illusory personal, small, self," leading to a direct experience of the "real, undifferentiated, trans-personal Self."

But, in that tradition, in its "purest" form, meditation is not a "goal in itself," and meditation is not a "means to an end" of achieving "altered states of consciousness."

But, there are countless other types, schools, philosophies, of "meditation," with very different conceptual underpinnings, some "secular," some "formally religious," and a wide range of behavioral practices associated with them.

On the "grossest" level, you might say we observe, when we see what appears to be hypnosis of one person by another, a loss of conscious, and subconscious, control of self from the person hypnotized to the hypnotist. But, then: there's stage hypnosis, self-hypnosis, so-called therapeutic hypnosis for behavior modification (such as giving up smoking, etc.).

While we typically associate meditation with acts of what we define, in western psychological terms, as individual "self-control," and "discipline," there are traditions in which group practices (rituals) leading to mass ecstasy are considered meditation (Sufi Zhikr ?).

From one perspective, "cultural identity," itself, can be considered a cohesive set of internalized hypnotic states of mind: continually reinforced from within, and without, the self, and modified in biological development throughout the life-cycle ... I am not referring, here, to the movie-series, "The Matrix" :) !

Suggested readings:

Hypnotism and psychotherapy: Milton Erickson ... Amazon page ....
Psychology and consciousness: books by Robert Ornstein ... Ornstein's website ...; books by Andrew Weill ... Weill's Amazon page ..., books by Steven Pinker, particularly, "The Language Instinct" ... Pinker's website ....
Meditation and Buddhism:

a. Donald Lopez ... "The Story of Buddhism: A Concise Guide to Its History & Teachings" ...: excellent overview of how original Buddhism became "modified:" incorporated a mixture of Vedic/Hindu classic ideas (influence of Advaita Vedanta, and Yogacara schools, for example); incorporated Sivaite Tantra as developed in what is now Bengal; and, later, became "deistic," with an elaborate hierarchic pantheon, in India, Tibet, China, Japan (into what can be loosely lumped together under the rubric "Mahayana Buddhism"). Depending on your biases, you might say, rather than "modified:" "evolved," or "corrupted.."

b. Theravadan Buddhist tradition (Sri Lanka, Southeast Asia), and Vipassana meditation (aka "mindfulness", or "insight" meditation): Walpole Rahula ... "What the Buddha Taught: Revised and Expanded Edition" ...; Thich Nhat Hanh ... Amazon page ...; books by Joseph Goldstein ... recommended: "Insight Meditation: The Practice of Freedom" ...; books by Bernard Kornfeld ... Amazon page ....


Why does journaling seem to reduce stress? When searching methods to reduce stress and discussing my problems with people I know, it was suggested to me that I journal thoughts, that is write down what worries me elaborately on paper.
I started doing it and I felt my mind having less 'noise' and clearing itself over time. However, I can't seem to understand why this worked and I can't find any good sources which explains why this worked in simple terms. Here is a website discussing journaling.
The closest analogy I can come to for how it feels to journal is how it feels to have a complicated thought relating to mathematics, in my head it is difficult to work out the algebra and see how it plays out but I can easily work my thoughts if I have a paper at hand (and a calculator handy).
Hopefully someone can shed some light on what's going on here.

As a person who has been journaling for more than twelve years ever since a very compassionate friend advised me to, I can attempt to answer why journaling seems to reduce stress.
AliceD mentioned that it's a way of writing down todos. That’s true. I also have Google Tasks for that.
The friend of mine deals a lot in algebra. We had spent a lot of time together working out mathematical problems, playing the guitar as well. It was thoroughly enjoyable to see him logically work towards the right answer. He believes in working things out by deriving from first principles.
We are quite religious so our journaling is quite spiritual in nature.
I didn't go into journaling knowing how good it would be, but looking back the benefits are invaluable.
Absolutely anything can go into your journal. I love to draw diagrams too.
In life we all make mistakes. I write down the fool things that I have done so that I can correct myself. Very often we do not know why certain people are antagonistic or get angry with us. This is because we are not omniscient like God. We do not know what the other person is thinking. By writing events down we are working out problems in our interactions with our fellow human beings. It greatly simplifies our thought processes. We can solve problems much more efficiently. We can improve our relationships with people.
I also write down what I am grateful for :
https://www.oprah.com/spirit/oprahs-gratitude-journal-oprah-on-gratitude ;
I used to have a lot of ‘noise’ in my head. I would think about what people said in great detail. Often people tell me not to think too much. It’s those stressful experiences that get me thinking the most. By writing everything down, I’m offloading my thought processes into my journal.
I sincerely want to help the person who posted this question as I feel so much affinity towards the points in Buraian’s question. I hope that my answer would also help the community and people who chance upon this question. I wasn’t expecting to write content targeted at scientific journals so please forgive my very informal first draft. I read the guidelines that personal experiences are valid answers so that’s why I decided to answer this question.
References
Deaver, S. P., & McAuliffe, G. (2009). Reflective visual journaling during art therapy and counselling internships: A qualitative study. Reflective Practice, 10(5), 615-632.
Smyth, J. M., Stone, A. A., Hurewitz, A., & Kaell, A. (1999). Effects of writing about stressful experiences on symptom reduction in patients with asthma or rheumatoid arthritis: A randomized trial. Jama, 281(14), 1304-1309.
Jamison, S. G. (2007). Online law school faculty perceptions of journaling as professional development: Influences, barriers and pitfalls (Doctoral dissertation, Capella University).


How to explain emoticons to an autistic person? I am currently chatting in an IRC and there is one girl (i think she's about 18 years old) and she has Asperger syndrome and therefore is unable to understand countenance and feelings. She told me that she only knows of happiness, sadness and rage but doesn't really understand what each means.

Furthermore the other people use emoticons like :), :(, >:[, ^^, ... and she really has problems to follow the discussion because she is really confused about all of this and when I tell her what each emoticon means five minutes later she will not be able to distinguish between these.

Do you have any suggestions on what to do to reassure her and maybe help her a bit so that she could enjoy the chat like everyone else, more or less? (Although I know she won't understand everything...)

First question, how deep is your knowledge about autism and Asperger Syndrome? Do you understand how autistic people think? Do you understand, what this girl have meant, when she have written, she doesn't really understand what each means?

For neurotypical person, a typical use-case for I understand you phrase is I know what you feel. But autistic people by understand mean in the first line to know the cause-and-effect. So your friend saying she don't understand what really each emotion means, could as good mean: I don't know how particular emotions are affecting the meaning of words the given person use.

If you want to explain emoticons to her, you should IMHO in first line explain, how particular emoticon in modifying the meaning of the sentence. So, think of emiticons not as the way to communicate emotions (which is of low importance to autistic people) but as the modifiers that change the meaning of the sentence or of the particular words.


Can positive self-affirmation improve mood? Most people get "depressed" every now and then - nothing serious, but people sometimes feel down. I am wondering if positive self-affirmation can make you happier by physically increasing the serotonin levels in your brain, or by some other mechanism.

Can positive self-affirmation improve mood?

Self affirmations is a kind of meditation, that is a specific state of mind, guided consciously. This kind of activity itself amends the person into a more direct and ordered state, actively improving the balance between the functioning of the sympathetic and parasympathetic systems.

This brings in the feeling of improvement and serves as a reward which helps to repeat self affirmation again. The more calm and ordered state of body lends even more control to the intellect which starts solving things, which also improves mood. This is widely used in medicine, for example, during child birth where the women are instructed to breathe calm and control the breath, which brings improvements of vital importance.

That being said, it is impossible to say, if self affirmation is primal. Maybe the fact itself of the sympathetic system function subsiding, gives birth to the feeling of improvement which is verbally perceived as a positive self affirmation. However, if free will is real then positive self affirmation is a good way to manifest it.

In any way the mechanism is complex and involves changing brain EM rhythms, probably with many other processes coming into play.


What is the study with the dual-task experiment that involved a colour-wheel change detection task? This may be a long-shot, but I'm looking for a paper that I vaguely remember reading a few years ago. Unfortunately I can't remember many details about the paper or its content, and thus my multiple attempts at keyword searches have failed. I'm posting this question in the hope that someone recognises the few details I do remember.

The paper presented more than one experiment, but the one I'm trying to recall involved a colour wheel/pie displayed in the centre of the screen. The slices of the pie were each a different colour and the colours would change a few times throughout each trial. There were only a small number of slices/colours. The observer's task was to count the number of times the colours changed. While doing this the observer also had to perform another task, for which the stimuli were shown on the rest of the display, in peripheral vision. I can't remember what the other task was, though it may have been a multiple object tracking task or a visual search task. The paper may have been about the effect of attentional load on working memory, though I'm not sure about that.

Your description sounds a little bit like Experiment 3 from

Hollingworth, A., Richard, A. M., Luck, S. J. (2008) Understanding the function of visual short-term memory: Transsaccadic memory, object correspondence, and gaze correction. Journal of Experimental Psychology: General, Vol 137(1), 163-181. PDF

See Fig. 7 on page 172 for a picture of the display utilized in this experiment.


Do you need sleep every night? I haven't slept for a day, but feel fine. It is sometimes assumed that one needs 8 hours of sleep each night, but I think this is sometimes not true.

Is it okay to get no sleep one night and then 8-9 hours sleep the next night, as long as it only happens occasionally (e.g., once a month)?

Here's why people need to sleep:

The brain does its "cleaning up" during sleep. As cells in the nervous system are active, waste products are produced. In the rest of the body, waste removal is carried out by the lymphatic system, but this system does not extend to the brain. Instead, cerebrospinal fluid (CSF) must be pumped through the brain tissue in order to flush waste back into the circulatory system where it can be excreted by the liver. Pumping CSF seems to require a great deal of energy, and researchers speculate that this energy expenditure is incompatible with the intense metabolic demands of brain cells during wakefulness. Also, cells in the brain shrink considerably during sleep, resulting in a 60% increase in interstitial space which allows CSF to wash more freely through the brain tissue. The consequence is significantly faster clearance of neurotoxic waste (e.g., β-amyloid).

http://www.sciencemag.org/content/342/6156/373
http://stm.sciencemag.org/content/4/147/147ra111


What is a "delayed match-to-sample task"? This question talked about how a "delayed match-to-sample task" can be used to measure an animal's working memory. What is a delayed match-to-sample task and how can it be used to measure working memory?

This kind of task is generally used when studying short-term memory. Typically, a subject is presented with some stimuli, followed by a probe item after a varying delay; subjects is then asked to recall (information retrieval) if the probe item was presented before (information encoding). A famous example is Sternberg experiment.

Such tasks can rely on non-verbal material, which makes them good candidates for behavioral studies with animals, but see

  Paule MG, Bushnell PJ, Maurissen JP, Wenger GR, Buccafusco JJ,
  Chelonis JJ, Elliott R. Symposium overview: the use of delayed
  matching-to-sample procedures in studies of short-term memory in
  animals and humans. Neurotoxicol Teratol. 1998
  Sep-Oct;20(5):493-502.

Some on-line demonstration can be found on the CANTAB testing battery: Delayed Matching to Sample (DMS).


Suggestion for wearable EEG headset We need wearable EEG headset with raw data output accessible from various platforms. I heard that devices like that have commonly the output encoded and available adapters are designed for one or just few platforms.

What we really prefer is device with output with standard (or well known) protocol, so we can create our own adapters.

Do you know what EEG wearable headset is the best for this purpose?

Emotiv EPOC+ Research Edition can be used on Windows, Linux and Mac.

It has 14 electrodes (+2 reference electrodes) and is used in several publicized studies.
You can access raw data via their software "Testbench" and output it as CSV or use third party software like OpenVibe, BCI2000 and EEGLab.

But the little drawbacks are:

It is a wireless device, so you really should put the usb dongle for wireless signal transmission with a long usb cable directly on the device, to overcome signal distortion
The reference electrode processing is done within the device
It seems to be more intended for consumer use than for medical use

EDIT about realtime usage of EPOC+ and OpenVibe Software:

There are studies and projects using the EPOC+ in realtime with OpenVibe. OpenVibe has a built in driver for the EPOC+ Research Edition

https://www.google.de/url?sa=t&rct=j&q=&esrc=s&source=web&cd=6&cad=rja&uact=8&ved=0ahUKEwiz2c-FpuXJAhVBhA8KHY0tD-IQFghbMAU&url=http%3A%2F%2Fwww.mtg.upf.edu%2Fsystem%2Ffiles%2Fpublications%2FSergio%2520Giraldo%2520-%2520Brain-Activity-Driven%2520Real-Time%2520Music%2520Emotive%2520Control.pdf&usg=AFQjCNEi0w9wT2eMlUUxvUyLj2jsKL1ewg&sig2=eJMv2T_OjE4tHr6JnbV4IA&bvm=bv.110151844,d.ZWU

And in this project two devices can be used, the EPOC+ and the the Enobio, which seems to be an intersting device, too. But I do not have enough knowledge about the Enobio to recommend it. But it might be even better as the EPOC+, as they have models with more electrodes. This is the realtime application for the two devices:
https://github.com/marcelfarres/Play_Your_Mood

By the way, OpenVibe features drivers for quite some EEGs, but it can only be used on Windows and Linux. On Mac you would have to compile it yourself.


"top-down" and "bottom-up" processes What kind of processes are "top-down" and "bottom-up" processes in the context of processing visual information in brain?

Context:

...There are discrete areas in the visual cortex dedicated to identifying specific aspects of vision – vertical or horizontal lines, colour or movement, for example. These elements are brought together to ensure that the total image arrives consistently in space and time. And even while our brains are swiftly adjusting to focus on the scene before us, images established in memory form feedback loops to confirm that we recognise what we have seen before, mediating prior knowledge into perception. As we acquire this personal knowledge then, we impose ‘top-down’ concepts on to ‘bottom-up’ perceptions. When we look at a cluttered scene in front of our eyes we may receive only partial information but our brains automatically fill in the gaps to make sense of things.

Top-down knowledge is knowing what a target is. When detecting an object, the rate at which you can detect it (measured via reaction time, or 'RT') is partially dependent on how fast you can identify it based on its sensory features.

Bottom-up knowledge is integrating recognition of the features, or the dimensions of an object, such as its color, orientation, and visibility. Neighbouring locations containing items with similar features tend to
inhibit each other, whereas neighbouring locations containing different features tend to activate each other, thus lending to the saliency of an object. Think of how salient a bright red stop sign is in the dark, and consider why that may be important to ensure the safety of nighttime drivers.

Once top-down and bottom-up systems have calculated their outputs, they are summed together in a spatially-guided 'activation map', thus lending itself to perception.

Both are important for object recognition and reaction time. For example, you must use top-down processing while driving to recognize that a streetlight is a streetlight. You then use bottom-up processing to recognize if the light is red, green, or yellow. Both are important mechanisms of perceptions to use, so that you can act appropriately and avoid an accident on the road.

If you are curious and want to read more, this paper examines both top-down and bottom-up mechanisms in visual search, and may prove useful to you.


Post alcoholic depression and mental health We all might have experienced a post-alcoholic hangover after heavy drinking. I think this includes a depressive state, which doesn't last long and wears off once we take rest.

My question is whether occasional excess alcohol consumption can make you depressed permanently? Specifically, I'm wondering whether occasional binge-drinking can lead to a permanent depressive state in the brain?

There have been several studies that show links between binge drinking and depressive symptoms.

However, it's hard to make any strong statement about a particular level of drinking, because drinking behaviors are so variable, and also to quantify the "level" of the effect on depression, because depression symptoms are also variable.

Finally, it's hard to make causal statements because alcohol use could be a coping mechanism for depressive symptoms rather than causal: many studies approach the relationship from the opposite direction, implying the depressive symptoms are causal for alcohol use.

I've pulled a few papers and can discuss them briefly, though this is not a comprehensive review.

Paljärvi, T., Koskenvuo, M., Poikolainen, K., Kauhanen, J., Sillanmäki, L., & Mäkelä, P. (2009). Binge drinking and depressive symptoms: a 5‐year population‐based cohort study. Addiction, 104(7), 1168-1178.

  "This study found a positive association between baseline binge drinking and depressive symptoms 5 years later." "Binge drinking was related to symptoms of depression independently of average intake."

I'd note that this study shows some truly massive relationships, odds ratios of 4-9 for some subcategories; it also seems to have some potential for demonstrating a causal role when they are comparing time 1 drinking to time 2 depression, though still not conclusive.

I think this study gets closest to testing what your question is asking, because it explicitly includes measures of hangovers/binging that are missing from some other studies. It also shows a dose-dependent relationship where more frequent binge drinking is associated with more depressive symptoms, but the relationship is still present even at lower levels of binge drinking compared to non-binge drinking.

Grant, B. F., & Harford, T. C. (1995). Comorbidity between DSM-IV alcohol use disorders and major depression: results of a national survey. Drug and alcohol dependence, 39(3), 197-206.

  "Virtually all odds ratios were significantly greater than 1.0, demonstrating that comorbidity of alcohol use disorders and major depression is pervasive in the general population. The magnitude of the association remained stable across the three time frames but diagnostic and subgroup variations in comorbidity were noted. The association between alcohol dependence and major depression was greater than the association between abuse and major depression and the association between alcohol abuse and major depression was consistently greater for females and blacks, compared to their male and non-black counterparts."

This studied focused on older adults, age 57+.

Hill, K. G., White, H. R., Chung, I. J., Hawkins, J. D., & Catalano, R. F. (2000). Early adult outcomes of adolescent binge drinking: person‐and variable‐centered analyses of binge drinking trajectories. Alcoholism: Clinical and Experimental Research, 24(6), 892-901.

  "Adolescent alcohol use did not predict educational attain-ment, crime, family roles, or depression."

This study patterned adolescent (<18yo) drinking behaviors into several categories and showed relationships between alcohol use and several other outcomes, but not depression, at age 21.

Okoro, C. A., Brewer, R. D., Naimi, T. S., Moriarty, D. G., Giles, W. H., & Mokdad, A. H. (2004). Binge drinking and health-related quality of life: do popular perceptions match reality?. American journal of preventive medicine, 26(3), 230-233.

  "After adjusting for confounding factors, frequent binge drinkers were more likely than non-binge drinkers to experience ≥14 unhealthy days (physical or mental) in the past month (adjusted odds ratio [AOR]=1.39, 95% confidence interval [CI]=1.24–1.56), primarily because they had more mentally unhealthy days than non-binge drinkers (AOR=1.52, 95% CI=1.32–1.75)."

This study combines depressive symptoms with other categories of mental/physical health to assay general quality of life.

And finally I'll end with one meta-analysis:

Boden, J. M., & Fergusson, D. M. (2011). Alcohol and depression. Addiction, 106(5), 906-914.

  The current state of the literature suggests a causal linkage between alcohol use disorders and major depression, such that increasing involvement with alcohol increases risk of depression.

They seem to make some arguments for a causal alcohol use -> depression relationship, though I haven't read closely enough to decide whether I am convinced by those arguments.


Is there a link between brain injuries (TBI) and PTSD? Could (TBI) Traumatic brain injuries be linked to Post Traumatic stress syndrome (PTSD)? I know there is a lot of concern with veterans and PTSD, but I am more interested in all the other situations/civilian cases of PTSD. From what I have read, there are overlapping symptoms between PTSD and TBI? Is it possible for someone to have PTSD from damage to the brain and not from a specific event?

It is reported that mild traumatic brain injury does not produce Post-Traumatic Stress Disorder however, according to this report in the American Journal of Psychiatry, severe TBI could possibly lead to PTSD in approximately 27% of cases.  In this study of 96 patients  (77 men and 19 women), after 6 months following hospital discharge for severe traumatic brain injury, 27% of them suffered PTSD.  Out of these patients:

19% reported having intrusive memories,
23% reported having nightmares,
31% reported having a sense of reliving the trauma,
65% reported avoidance of thoughts,
65% reported avoidance of places; and
73% had signs of hypervigilance.

However one point of note that the report detailed was that

  First, our patients were not selected consecutively, and their
  responses may not be representative of populations with severe
  traumatic brain injury. Second, we did not obtain neuropsychological
  information on each patient.

I must admit that when I was looking at the report, due to the high number reliving the trauma and avoiding certain places, I wondered whether the trauma leading to PTSD was actually the brain injury or if it was the traumatic effect of the event which led to the brain injury.

Another point of note is that it was also reported in a committee hearing in the U. S. House of Representatives, that people with TBI are more likely to develop PTSD than those who have not incurred a brain injury

Personally, from looking at these reports, I think the jury may be still out on this one.


What is the meaning of the brain scan of borderline patients? Starting from mark 21:50 in the lecture BPD-related cognitive-perceptual difficulties and challenges in their diagnosis and treatment, there is an image of brain scan in borderline patients:

What does this image say? The speaker says that it's something about uncontrollable manipulation of borderline patients, but I'm not really sure.

This picture in her talk (which is very good, by the way) refers to the study about amygdala hyperreactivity - see below. Essentially the picture shows fMRI scan differences between  controls and borderline patients when looking at neutral, happy, sad and fearful faces. Neutral faces and fixation point were used to transition between the exposure blocks to the emotional faces. Authors state the study points towards the role of greater amygdala activation in borderline patients being a key component to their emotional vulnerability in context of disturbed interpersonal relationships. To put it very simply - borderline patients' amygdala response (i.e. mostly - fear) is more sensitive. The speaker does not talk about the above picture in particular; it rather serves as a general illustration for her presentation.

Donegan, N. H., Sanislow, C. A., Blumberg, H. P., Fulbright, R. K., Lacadie, C., Skudlarski, P., … Wexler, B. E. (2003). Amygdala hyperreactivity in borderline personality disorder: implications for emotional dysregulation. Biological Psychiatry, 54(11), 1284–1293. https://doi.org/10.1016/S0006-3223(03)00636-X

In addition I found a good overview article on neuroimaging in borderline patients:

Lis, E., Greenfield, B., Henry, M., Guilé, J. M., & Dougherty, G. (2007). Neuroimaging and genetics of borderline personality disorder: a review. Journal of Psychiatry & Neuroscience, 32(3), 162–173.


Research that shows that people infer causation from correlation It is well known and frquently quoted that "correlation does not imply causation".

Nonetheless, I've scoured the wikipedia article "Correlation does not imply causation" and the relevant keywords in google scholar, and could not find any research that clearly shows that people use correlation to infer causation. There are some examples from popular newspapers and mentions of "cum hoc ergo propter hoc" as a long known fallacy, but no empirical research.

Is there any research that shows that people have a "correlation implies causation" fallacy?

A much-cited reference on the statistical backgrounds is this one:

Simon (1954), Spurious Correlation: A Causal Interpretation, J Am Stat Assoc; 49(267)

A more recent, open access but applied research paper on the topic is:

Parise et al. (2013), When Correlation Implies Causation in Multisensory Integration, Curr Biol; 22(1): 46–9


Do we recognize ourselves better when we see our mirror image? A friend of mine recently noticed that we both have a birthmark on the face. He looked at me and said that we have exactly the same mark. But he has it left and I right. But, when looking in a mirror, we see it on the other side.

So, I wonder: Do we recognize ourselves better when we see our mirror image compared with e.g. a video of ourselves? Where is this studied?

Bredart (2003) discusses your exact hypothesis and reports the results of a couple of studies. I'd recommend having a read of the article.

The authors acknowledge that in contrast to familiar others the experience of our own face typically comes through self-inspection in mirrors.

They summarise some relevant literature:

  Troje and Kersten (1999) showed that participants were faster when
  naming frontal views compared with profile views of their own face,
  and that this advantage for frontal views disappeared when naming
  familiar colleagues’ faces. In addition, Laeng and Rouw (2001) showed
  that the full-frontal view is superior to other views for facial
  self-recognition but not for the recognition of other people’s faces.
  A pose corresponding to 22.5 degrees from the frontal view seems to be
  optimal for other people’s faces. However, for highly familiar faces
  (e.g. faces of close friends or partners), the frontal view could be
  recognised as quickly as the 22.5 degrees view. In short, because of
  ecological constraints on visual experience, self-recognition is
  easier from frontal views than from other views. This superiority of
  frontal views was not observed for other highly familiar faces.

They also discuss one methodology that involves "searching for a target face among a set of other faces". Thus, the speed of finding the face is one way operationalising familiarity.

With regards to their findings, the following quotes the abstract:

  Experiment 1 examined our ability to recognise the usual horizontal
  orientation of our own face (mirror orientation) as compared with
  another very familiar face (normal orientation). Participants did not
  use the same kind of information in determining the orientation of
  self-face as in determining the orientation of the other familiar
  face. The proportion of participants who reported having based their
  judgement on the location of an asymmetric feature (e.g. a mole) was
  higher when determining their own face’s orientation than when
  determining the other familiar face’s orientation. In experiment 2,
  participants were presented with pairs of manipulated images of their
  own face and of another familiar face showing conflicting asymmetric
  features and configural information. Each pair consisted of one
  picture showing a given face’s asymmetric features in a
  mirror-reversed position, while the facial configuration was left
  unchanged, and one picture in which the location of the asymmetric
  features was left unchanged, while the facial configuration was
  mirror-reversed. As expected from the hypothesis that asymmetric local
  features are more frequently used for self-face judgements,
  participants chose the picture showing mirror-reversed asymmetric
  features when determining the usual orientation of their own face
  significantly more often than they chose the picture showing normally
  oriented asymmetric features when determining the orientation of the
  other face. These results were explained in terms of competing forward
  and mirror-reversed representations of our own face.

Reference

Bredart, S. (2003). Recognising the usual orientation of one's own face: the role of asymmetrically located details. Perception, 32, . DOC
Laeng B, Rouw R, 2001 “Canonical views of faces and the cerebral hemispheres” Laterality 6 193-224.
Troje N F, Kersten D, 1999 “Viewpoint-dependent recognition of familiar faces” Perception  28 483-487.


Why aren't Connectionism and Dynamicism considered part of the Computational Theory of the Mind? In the Wikipedia article for Computational Theory of the Mind (NOT to be confused with Computational Representational Understanding of Mind which includes Connectionism), it is mentioned that alternatives to this philosophical view are Connectionism and Dynamicism (though there is some debate as to how different Dynamicism is). Why is this? Since they still use mathematical models run by computers, which still take in information and still process it, they seem to still fall under the Computational Theory of the Mind. What distinction am I missing here?

The Computational Theory of Mind is not that the mind does some form of computation in the wide sense of computation. Rather, look at the examples for the CToM given in the Wikipedia article; people like Fodor, Pinker, Marr. Their view is very much the opposite to the Connectionist position of West Coast scientists like Rumelhart, Elman and McClelland. Both assume the brain does some form of computation, but they differ greatly about what kind of computation it is doing. Fundamentally, by the CToM, cognition is symbol manipulation and the mind Von Neumann-like (with a central-processor accessing memory), and to Connectionism, it isn't.

Historically, much of the foundations of CToM as it is currently used was first and best articulated by David Marr (although the basic thought is of course much older). Marr assumed cognition can be described on 3 distinct levels;

a computational level, which describes what job the system is supposed to do; for example, the visual system is supposed to discover cues for depth, object boundaries, and so on
The algorithmic level is a description of which calculations are used to perform this computation; for example, in the case of vision, by computing a Laplacian transformation.
The implementational level is how neurons are actually wired together to perform these algorithms - the wet, and to many researchers, not so interesting part.

This framework is basically what much of modern CToM operates within.

Fodor or Pinker assume minds operate like a specific form of computer: somewhat akin to a Von Neuman machine. Specifically, minds do symbol manipulation. Symbols are distinct, abstract cognitive entities which are assigned some meaning. Typically, they represent something. So to a CToM person, the mind works by taking a symbol, such as a low-level representation of a small part of the outside world, and performing an operation on it. In vision, it might take low-level visual items and add them together to construct a 3D representation of the outside world. In language, it might take lexical units and operate on them using linguistic rules, yielding a linguistic/semantic representation.

Importantly, in all of these, the thing which is operated on (the symbol) and the thing which does the operation (some mental module) are distinct. Symbols are manipulated via mental modules showing rule-like, algorithmic behaviour. In at least some theories, each manipulation within a module follows in sequence after another.

So CToM typically entails a symbolic and representational theory of mind; it also often comes as a modular, nativist, and universalist theory.

Connectionism, in contrast, does not assume any of these, and it was in fact originally proposed as a direct answer and alternative to the CToM. In connectionism, the 3 levels approach is often not seen as foundational, or even useful; to study how neurons work is to study how cognition works. In Connectionism, there is no central processing unit and no distinct symbol. There is no difference between "data" (symbols, representation) and the processor. Processing and symbols are implicitly distributed amongst neurons; processing doesn't happen in modules and in sequence, but in parallel. The central unit is not the module, but the network. Neuronal systems don't implement specific rule-like operations like a "normal" computer program, but deal with the world by finding patterns in the input and linking it to dynamically created response patterns. In some frameworks, representationality is disputed.

The two Stanford Encyclopedia articles on CToM and Connectionism are a good introduction to the topic and the long and intense argument between the two schools about what the mind does.

The same spiel also goes for the Dynamical Systems take on cognition, because when compared to CToM, the two - Dynamicism and Connectionism - are united in what distinguishes them from the CToM. When comparing Dynamicism to the CToM at length, van Gelder immediately and explicitly aligns connectionism and dynamicism when comparing them to

  ... the computational hypothesis (CH) that cognitive agents are basically digital computers. Perhaps the most famous rendition is Newell and Simon’s doctrine [:] “a physical symbol system ..."  ...
  In recent years, however, the ... alternative has been gaining momentum. One of the most notable developments has been the rise of connectionism, which models cognition as the behavior of dynamical systems ...

Dynamicism, like connectionism, is non-symbolic, not sold on the Von Neumann model, and emphasizes adaptive processes (such as learning) over static, modular faculties. Moreover, Dynamicism emphasizes interactions with the outside world as well as embodied, non-symbolic phenomena.

As a post-script, I want to note that Marr is perhaps a bit straw manned when he is (by people on the CToM side, usually!) painted as the Arch Symbolist. Marr developed his foundational work together with Poggio, who has worked with neural networks and stochastic models a lot, and is sometimes presented as a Dynamicist(!).

Also: to add to the confusion, CToM research usually features much less interest in explicit computational models than connectionist work. Connectionist research almost always features computer implementations of models, and dynamicism can be heavy on the formulas. CToM research often prefers qualitative descriptions.


Do high heels increase female attractiveness in men only through indirect means? It seems widely accepted that, overall, men tend to find women in high heels more attractive.  (There will, of course, be many exceptions to this rule.)

  "High heels may well be the most potent aphrodisiac ever concocted." -- Rossi 1981

However, the increase in attraction seems to be only indirectly ascribed with wearing high heels.  Typically this is described along the lines: high heels cause a change in the posture of the female, which the male finds (sexually) attractive.

  Question: How can we exclude the possibility that the high heels themselves are not the main cause of the increase in attractiveness?

That is, how can we exclude the possibility that men, overall, primarily just like the sight of women in high heels, for some reason or another?

My thoughts:

If the increase in attractiveness were primarily due to these indirect factors, then we should see a comparable increase in attractiveness e.g. if a woman were merely to stand on a slope.  (Although, this would not account for the addition factors, such as gait, and the sound made when walking in high heels.)
There are things that women do, such as fingernail painting, which increases attractiveness, but (arguably) not sexual attractiveness.  It seems plausible that the "femininity" associated with wearing high heels (as with fingernail painting) could be a large factor in the increase in attractiveness.

References
Rossi WA. (1981) High heels: the agony and the extasy. Journal of the American Podiatry Association 71(12), 698-699.

It is probably quite simple to test whether high heels themselves are the main cause of the increase in attractiveness, or rather the changes to posture imposed by them - just let participants rate the attractiveness of women who do not wear high-heels, but, for instance, hold them in their hand.

Alternatively, you could expose one half of your participants to high heels and the other half not. Afterwards let them rate pictures of women and compare the mean ratings of the groups.

In principle, you could a multitude of experiments with women and high heels - as long as the women do not wear the high heels, you can exclude that the effect on posture explains your results.

An alternative approach, suggested by Artem Kaznatcheev in the comments, would be to compare the attractiveness ratings on women with and without high heels while their feet are not visible (e.g., covered or removed from the picture). Finding the same rating difference like observed with visible feet would suggest an effect of posture caused by high heels, rather than high heels themselves. (Actually you would need at least an two-by-two design ([high-heel vs. no-high-heel] x [feet-visble vs. feet-invisble]) to draw this conclusion.)


What causes the spokes of a Wagon Wheel to "move"(rotate) in the opposite direction of the Wagon Wheel itself? Is it my mind's eye that is the problem or is this a "artifact" of the film? I would think it was my mind's eye as the medium of film is purely analog and not a digital representation that exists to conform to "what should be" and not in fact what is visually seen.

This happens when the wheel is observed as an image through a projector or with light shining on it that is periodically blinking. What you are seeing is essentially the additive effects of two periodic functions, the first is the period of the light flicker and the second is the period of the wheel rotation.

So, if the wheel is rotating at a frequency that is evenly divisible by the frequency of the light, then the spokes appear to be standing still. If it is rotating faster, then they are appear to be moving in one direction. If it is rotating slower, then it appears to be moving in the other.

Under household lighting, the light pulses are at 60 Hz. The frame rate of movie cameras is usually 24 Hz.