Is there any scientific data showing one can learn while sleeping? Time is short in the days of learning for me but I like listening to lectures and case studies about code in my field. I've thought about getting a Bluetooth Sleep Headphone to possibly listen to these lectures and studies while sleeping.

However, upon my research I've only be able to find on this site one a Q&A without an answer: "Can one learn whilst sleeping? Can one solidify a memory & study for exams by listening to recordings while asleep?".

In my research and Google kungfu I've seen questionable sites that indicate as yes and some no but I was wondering have there been any creditable university case studies that show wether this is factually possible?

I don't think that it is possible to learn new facts while sleeping, but it is certainly possible to reactivate certain memories during sleep and thereby affect the probability of those memories being retained.

In one study, participants learned a visuospatial task while smelling an odour. They were better at remembering how to perform the task if they were subsequently exposed to the same odour during sleep.

  Reactivating Memories during Sleep by Odors: Odor Specificity and
  Associated Changes in Sleep Oscillations, Julia S. Rihm,  Susanne
  Diekelmann,  Jan Born and  Björn Rasch
  https://www.mitpressjournals.org/doi/abs/10.1162/jocn_a_

In another study, participants had to learn spatial locations for some objects and a sound associated with each object. The sounds associated with some of these objects were played back to them during sleep. Upon awakening, they were better at recalling the locations of objects whose sounds they had heard during sleep.

  Strengthening Individual Memories by Reactivating Them During Sleep,
  John D. Rudoy, Joel L. Voss, Carmen E. Westerberg, Ken A. Paller
  https://science.sciencemag.org/content/326/5956/1079

In another study, participants remembered melodies better if they later heard those melodies during sleep.

  Cued memory reactivation during sleep influences skill learning James
  W Antony, Eric W Gobel, Justin K O'Hare,  Paul J Reber& Ken A Paller
  https://www.nature.com/articles/nn.3152


Is there a way to test brain activity/aptitude on a measurable scale in order to identify a suitable occupational aptitude? It seems individuals are able to adjust their cognitive aptitude to some degree through nurture, which is controlled by various elements such as environment and conditioning. However, they're stuck with their nature - heredity. Is it possible to measure and compare one's capacities to occupational cognitive demands?

According to the United States Armed Forces, it is possible. They do something similar to what you propose with the Armed Services Vocational Aptitude Battery. However, according to the section "Test Validity" of the linked Wikipedia article, there is some debate about whether it only measures literacy or IQ.


How do people with a split brain experience reality? Some people with severe epileptic seizures have the connection between their two brain halves cut. How appears reality for them, and why does this procedure helps them?

The corpus callosum is the largest of the commissural neural pathways, linking the cerebral cortex of the left and right hemisphere. The sectioning of this tract is called a corpus callosotomy, which disconnects the two sides of the neocortex.

A callosotomy is used in cases of intractable epilepsy, i.e., epilepsy that cannot be treated sufficiently with medication.

Patients with their corpus callosum severed have been shown to have difficulties in tasks that require lateralized brain areas to work together. For example, the left visual field is processed in the right hemisphere in the brain (and vice versa), speech and language centers are primarily located in the left hemisphere (in most people) and the right hemisphere specializes in visual-spatial processing and facial recognition.

When experiments are done under laboratory conditions, the lateralization of the brain becomes quite evident in these patients. For instance, a compelling experiment is shown in Fig. 1. When a split-brain subject is shown a word in the right field of view, the image is processed in the left hemisphere in the brain. The case shown shows the typical case where the language centers reside in the left hemisphere too. In this case, the subject is able to say what the word was ('face'). However, when the same word is shown on the left, the visual image is processed in the right hemisphere, where the speech centers are less well represented, if at all. In this case the subject cannot verbalize what they saw, but they are able to draw it(!). And in fact, subjects may say they saw nothing at all when a visual stimulus is presented on their left side, but still make a motor response to it (e.g., press a button when instructed to do so when a stimulus pops up).

Fig. 1. Split brain experiment. source: Nature

Why does callosotomy help epilepsy patients? When conventional methods fail to treat severe forms of epilepsy (intractable epilepsy), sectioning the corpus callosum may help to prevent the seizure from spreading from one hemisphere to the next. Generalized seizures result in loss of consciousness only when both hemispheres are affected. Often, seizures start in a hot spot, called an epileptic focus. From there it spreads over the cortex and the subject gradually loses consciousness. Once it jumps over, via the corpus callosum, the subject loses consciousness entirely. Hence, severing the major connection between the two hemispheres can keep seizures from evolving into full-blown generalized seizures. However, callosotomies have been really rare in the past and they are hardly performed today, due to the advances made in anti-epileptic drug development, combination therapies, micro surgery, etc.

Resource
- Nature News, March 2012


What decision problems are better answered with analytic thinking, and what are better answered with intuition? Most Western philosophy and psychology argue that deliberating carefully and rationally is the right way of reaching a decision. "Don't let emotions turn you" they might say. The splitting of the mind into the two systems (intuitive System 1 vs. rational System 2) have just sharpened this attitude. In contrast, many studies have shown the superiority of making decision by not thinking about it (e.g. Dijksterhuis), or by relying on intuition (e.g. Kahneman and a long list of many others).

It seems that there is no absolute way that is better then the other, rather some decision problems are better handled with careful thinking, while others are solved better with "gut feeling". What are the characteristics that differentiate the two?

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

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

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

His examples include:

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

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

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

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

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

Hope this helps, sorry about the rambling!


Quick responses/Time & lintelligence Is the ability to answer a given question correctly quicker a measure of that individual being more intelligent than the person who answered correctly, but slower (This based on both individuals having no physical handicaps)?

There is some evidence of a moderate correlation between response times (on very simple tasks) and intelligence constructs like IQ. Here are two relevant papers and their abstracts:
Deary, Der, & Ford (2001)

The association between reaction times and psychometric intelligence test scores is a major plank of the information-processing approach to mental ability differences. An important but unavailable datum is the effect size of the correlation in the normal population. Here we describe the associations between scores on a test of general mental ability (Alice Heim 4, AH4) and reaction times using a ‘Hick’-style device. The sample is 900 people aged 56 years who are broadly representative of the Scottish population. AH4 Part I total scores correlated −.31 with simple reaction time, −.49 with four-choice reaction time, and −.26 with intraindividual variability in both reaction time procedures. The correlation between AH4 scores and the difference between simple and four-choice reaction time was −.15. Separate analyses were conducted after partitioning the total group according to sex, educational level, social class grouping, and number of errors on the four-choice reaction time task. None of these factors significantly altered the effect sizes. This is the first report of reaction time and psychometric intelligence in a large, normal sample of the population. It provides a benchmark for other studies and suggests larger effect sizes than the majority of present studies, which are dominated by young student samples.

van Ravenzwaaij, Brown, & Wagenmakers (2011)

Research in the field of mental chronometry and individual differences has revealed several robust regularities (Jensen, 2006). These include right-skewed response time (RT) distributions, the worst performance rule, correlations with general intelligence (g) that are more pronounced for RT standard deviations (RTSD) than they are for RT means (RTm), an almost perfect linear relation between individual differences in RTSD and RTm, linear Brinley plots, and stronger correlations between g and inspection time (IT) than between g and RTm. Here we show how all these regularities are manifestations of a single underlying relationship, when viewed through the lens of Ratcliff’s diffusion model ( Ratcliff, 1978 and Ratcliff et al., 2008). The single underlying relationship is between individual differences in general intelligence and individual differences in “drift rate”, which is just the speed of information processing in Ratcliff’s model. We also test and confirm a strong prediction of the diffusion model, namely that the worst performance rule generalizes to phenomena outside of the field of intelligence. Our approach provides an integrative perspective on intelligence findings.

To summarize: the first paper demonstrates a moderate correlation between faster reaction times and the AH4 test, which measures "general mental ability." The second paper shows that these differences, and many others reported in the literature, and predicted by increasing the drift rate in a drift-diffusion model. The drift rate is generally associated with faster information processing.


Is k-winner a biological plausible model of inhibition? In the Leabra cognitive architecture, sparse representations are created by simply ignoring all but the k strongest activations, if I understand correctly. In Hierarchical Temporal Memory, instead, each firing neuron inhibits an area of a given radius during this time step. To me, this seems more plausible due to the locality of neuronal connections.

Is the k-winner inhibition biologically plausible?

As mentioned by honi, it is possible to have bio plausible k-means. However, neither Leabra nor Hierarchical Temporal Memory (HTM) use it.

As Section 3.5.1 of How to Build a Brain by Chris Eliasmith notes:

  There are basic computational methods underlying Leabra that are of
  dubious plausibility. The most evident is that Leabra directly applies
  a k-Winner-Takes-All (kWTA) algorithm, which is acknowledged as
  biologically implausible: “although the kWTA function is somewhat
  biologically implausible in its implementation (e.g., requiring global
  information about activation states and using sorting mechanisms), it
  provides a computationally effective approximation to biologically
  plausible inhibitory dynamics”
  (http://grey.colorado.edu/emergent/index.php/Leabra; see also O’Reilly
  & Munakata [2000], pp. 94-105 for further discussion). In other words,
  the actual dynamics of the system are replaced by an approximation
  that is computationally cheaper on digital computers.

The same problem occurs with the HTM as discussed in this forum post by Travis DeWolf:

  In the second step of their spatial pooling, they
  find the k most active columns, to apply learning to only these
  columns. Dynamically, setting up WTA with lateral inhibitory
  connections is notoriously very tricky, and isn't something that can
  be done in a single time step. On top of that, controlling the
  learning so that it's only applied after the network has settled on a
  set of winners is a whole other issue. It might be the case it works
  running the whole time as the WTA circuit settles, but the dynamics
  are complex and can't just be assumed to work.

To summarize, k-winner inhibition is possible, but it's not used in a biologically plausible manner in either Leabra and HTM.


Would non-neural physiological insights be considered to be in the field of neuroscience? For example, would e.g. SCR (skin conductance response) or hormone level be considered to be "neuroscientific measures" according to general definition of neuroscience?

There is increasing scientific evidence to incorporate other organ systems when considering the whole function of the nervous system. Neuroendocrinology, neurogastroenterology, and neuroimmunology are burgeoning fields of research.

If for instance, you were interested in the effects of stress on neurodevelopment, you would likely want to be measuring cortisol levels in your animal model.

If you were performing a study on human fear response, you might want to record SCR in addition to other measures (EEG, fMRI, etc.).

The definition of neuroscience is intentionally broad. There are many biochemists, for instance, who are interested primarily in cell structure, stability, and the transport mechanisms within who study neural tissue specifically because neurons happen to be interesting cases (axons can be very long, how do nutrients and proteins get to where they need to be?).

--

Clin Psychopharmacol Neurosci 2013; 11(3): 107-117  https://doi.org/10.9758/cpn.2013.11.3.107

Ann Clin Biochem. 2017 May;54(3):308-322. doi: 10.1177/0004563216687335. Epub 2017 Mar 16

J Del Signore, Steven & Rodal, Avital. (2016). The membrane strikes back: phosphoinositide binding regulates Skywalker function. Nature Structural & Molecular Biology. 23. 956-957. 10.1038/nsmb.3313.

J. Herzog, Josiah & Deshpande, Mugdha & Shapiro, Leah & Rodal, Avital & Paradis, Suzanne. (2017). TDP-43 misexpression causes defects in dendritic growth. Scientific Reports. 7. 10.1038/s41598-017-15914-4.


Significant baseline, Oddball paradigm I recently conducted an EEG experiment using a passive Oddball paradigm with two experimental conditions : standard stimuli (occurring with a 85% probability) and deviant stimuli (occurring with a 15% probability). This experiment was conducted on 10 participants.

ERP were recorded with 64 electrodes.

An ANOVA test on the prestimulus baseline period yielded a significant effect of the condition. I have observed a difference between standard stimuli's wave and deviant stimuli's wave. There shouldn't be such a difference between these two but I understood that this difference is caused by a smaller number of trials in the deviant condition than in the standard one.

However, I'm still wondering whether this significant difference can be caused by the small number of participants (n=10) or by too small inter-stimulus interval (ISI=1500ms) ? How do you suggest I should deal with this significant baseline regarding the understanding of MMN/P3 effects ?

I looked on cogsci.SE and I didn't find anything relevant to my question.

How many trials do you have per condition? With a small number of trials in the deviant condition, and a small number of participants, these things can happen.

The ISI would not cause this per se, however, have you considered looking at effects of the previous trial? You can analyze the baseline intervals as a function of what type the previous trial was, and see if there is a difference in the period following deviants or standards.

You could also try to randomly sample as many standard trials as you have deviants per participant, and then re-do your analysis and see what happens. You can make a loop and do this many times, and then look at the median p-value.

It could also be that some small number of subjects is introducing some skew to your results. You could try to re-do your analysis on a single subject level, comparing standard and deviant trials within subjects. Then you could see whether all your subjects have this effect or only some of them. If it's only some, you could look at their data more carefully for potential outliers. If it's a general thing, I'd look into the effects of the previous trial.

And if it's the previous trial effect, you can just remove all standard trials preceded by a deviant and try again.

All that being said, even if you have a baseline difference, it might not really matter: this is what baseline correction is for. But I agree that it's disconcerting.

I'm also a bit confused why you would use an ANOVA to compare two conditions, and not a t-test. Maybe I'm not understanding you design completely.


Do "overview" sections increase learning outcome? Suppose a math textbook contains an overview chapter for each part of the textbook. The intent of those overview chapters is to motivate and introduce the new mathematical concepts which will be discussed in the respective part of the textbook. For example, why do we need the mathematical concept? How did the concept evolve in history? What will be the content of the next chapters?

In this context, will the overview sections facilitate learning? How important are overview chapters in textbooks for the success of learning?

Note: I reasked this question on matheducators.stackexchange.com.

There is something called "advance organizer", that traces back to Ausubel (1960). It is some kind of overview, in which a short summary is given and (more important), in which the following  topic is connected to prior knowledge (= Associations are being activated). In that sense it activates schemes, in order to assimiliate the new knoweldge to the old one or to accomodate/correct the prior knowledge. So, to be useful, advance organizers should have certain features:

Connections between the following topic and prior knowlege
Catch the attention of the student
Be concret, insted of abstract

F.e. Before teaching equations the teacher could give the analogy of a scale.

From a scientific perspective it is known, that advance organizers can have supportive effects on learning and retention (see f.e. Luiten, Ames & Ackerson, 1980)

Luiten, J., Ames, W., & Ackerson, G. (1980). A meta-analysis of the effects of advance organizers on learning and retention. American Educational Research Journal, 17(2), 211-218.


About the possibility of 'Robot Psychology' If a Robot system with an advanced A.I. operating system had the 'ability' to 'do' 'undirected' or 'semi-undirected' introspection and 'form' all sorts of 'thought' structures about any subject matter (that didn't directly have something to do with important 'operating' functions) could these not-necessarily important 'thought structures' and the 'managing' of such cause something analogous to psychological problems in the robot?

Depending on the definition of "psychology" and "psychological problems" sure. The APA defines psychology as "the scientific study of the behavior of individuals and their mental processes." If we take this to only apply to biological systems (as I am sure many researchers do) then no, because the robot is not a biological system and therefore we can not study it under the heading of psychology and we would probably study it under something more akin to "engineering". However, if one is happy applying the same to robots, as I assuming you are, then yes.

Assuming the latter, and if you think that a being's "'ability' to 'do' 'undirected' or 'semi-undirected' introspection and 'form' all sorts of 'thought' structures about any subject matter" is a cause of psychological problems, and we are further assuming that a robot could do this, then yes, the robot will have psychological problems by definition. (Is there direct evidence suggesting these are causes though?)


What is "Predictive Reverse Engineering" and how can it be used for understanding brain structure? Here is a quotation from the paper Markram et al., Introducing the Human Brain Project :

  New informatics and modeling approaches are making it possible to
  reverse engineer the detailed structure of the human brain without
  resort to invasive methods of data collection. By analyzing very large
  volumes of data, from different –omics levels, we can identify
  principles of design that cannot emerge from smaller studies and that
  make it possible to extrapolate data collected in one species to
  others, including humans. This Predictive Reverse Engineering will
  allow us to predict how different patterns of gene expression produce
  neurons with different morphologies expressing different molecules,
  and different synaptic connection

(The Human Brain Project is a research project, established recently, which costs around €1 billion and is mostly funded by the European Union. The project's aim is to create a detailed computer simulation of the human brain for medical and neuroscientific research)

But there is no reference as to what this "Predictive Reverse Engineering" method actually is. I couldn't find any reference to it myself either. Can you please tell me about this or attach relevant links?

Thanks.

I am unfamiliar with the term "Predictive Reverse Engineering" but your question seemed very interesting.  Informally speaking, "Predictive Reverse Engineering" seems to denote trying to reverse engineer the brain's architecture in a way that is also able to predict brain function, which was not used in the process of constructing the brain's map. In other words, to try to construct a model of the brain from sparse data, which is able to predict the results of novel observations. Like I said, I'm no expert in the subject so I poked around a bit and here is what I found. I hope it helps.

The human brain project (HBP) has a list of key results and publications list. The most noteworthy of all seems to be Markram et al (2015), which is a huge paper that shows the results of a first draft reconstruction of the rat's somatosensory cortex. This paper has a very long suppplementary information section describing how they reconstructed neuronal morphologies from the experimental data.

The introduction of the above article cites many works that communicate how the anatomical and physiological properties of synaptic connections can be characterized (Cobb et al., 1997; Feldmeyer et al., 1999; Frick et al., 2008; Gupta et al., 2000; Mason et al., 1991;
Reyes et al., 1998; Thomson et al., 1993). It also lists some methods used to map pre and postsynaptic neurons for individual neurons, such as: retrograde and anterograde tracers and trans-synaptic viral vectors, imaging with array tomography, and saturated reconstruction with electron microscopy. The references they cite for these methods are: Boyd and Matsubara, 1991; Callaway, 2008; Glenn et al., 1982; Kasthuri et al., 2015; Killackey et al., 1983; Micheva and Smith, 2007; Micheva et al., 2010; Wickersham et al., 2007.

The methods listed above by no way map the entire somatosensory cortex. They gather data from a sparse locations and Markram et al present a computational method to reconstruct the entire microcircuitry, i.e. reverse engineer the somatosensory cortex from sparse observations. They show that they are able to cross validate their algorithmic approach with the data and also account for new experimental observations.

Another paper that you could find interesting is Frackowiak and Markram (2015), "The future of human cerebral cartography: a novel approach", which is a perspectives article on how the brain can be cartographically mapped to understand function.


How does TD-learning explain trace conditioning? I'm reading Reinforcement learning and causal models by Sam Gershman, which states that TD-learning provides an account of second-order conditioning that provides an explanation for the phenomenon occurred in trace learning (pg. 7, 3rd paragraph). The idea is as follows:

In trace conditioning, a reward is presented after some cue A with some relatively large time delay. If a second cue, B, is presented during this gap, this facilitates the learning of a conditional response to A. He says that this is because B receives a large positive value which generates a large positive prediction error at the offset of A. I do not see why this is true. If you look at TD-learning, the values of A and B should strictly be a function of their temporal distance from the reward, i.e. $$\gamma^{T-t} r_T$$, where $t$ is the current time and $T$ is the time of the reward. He goes on to say that this is related to how the prediction error is changed with the presence of B. Could somebody explain to me why having B increases the prediction error?

See my comment above, but it is possible to assume that B acquires the same reward value as the original reward, so B can then be treated as a reward, which in turn brings A closer to the reward event (now at time B). Does that make sense? In other words, the addition of B allows the reward value to accrue to B and thus brings A closer to reward.


Does being read to improve reading speed? So my girlfriend is not what you would call a fast reader. She understands completely what she reads, but she reads rather slowly. I'm trying to be a good boyfriend and help her out with this, but the only two things I can think of that would help are getting her to read a lot and maybe being read to. I know in my personal experience that being read to helped to improve my reading speed but I may just be an outlier.
I guess what I'm trying to say is this: "is being read to actually something that improves reading speed?" and "other than the aforementioned methods, are there other ways to improve reading speed?"

There is no scientific proof that being read at an adult age enhances reading speed.

However, slow readers read faster when the format of a document is enhanced. Is your partner more responsive to a specific background color, a particular contrast or a particular font? Such visu-attentional factors play a fundamental role in our ability to read.

You may want to investigate the letter spacing effect for example. It has been shown that children with dyslexia read faster and with less errors when a paragraph is less crowded. Here are two paragraphs written with the exact same font (spacing between lines and spacing between letters are wider in the second paragraph, with an extra space between words).

Here is the image:

There is also a ton of other possibilities that can be tested using a word processor such as Microsoft Word (spacing is sometimes called kerning), or activating the Accessibility option in Mac's preferences. What you have to keep in mind is that, once you find a combination that feels OK, reading a lot makes you read faster.

REF: Zorzi et al. (PNAS, 2012). Extra-large letter spacing improves reading in dyslexia.
http://www.pnas.org/content/109/28/11455.short


How does fear paralysis occur? (This question is in relation to this question here)

How does fear paralysis occur? What is the mechanism that makes this happen in brain?

Taken from here

The Fear Paralysis Reflex begins to function very early after
conception and should normally be integrated before birth.  It can be
seen in the womb as movement of the head, neck and body in response to
threat.
It is sometimes classified as a withdrawal reflex rather than
a primitive reflex. If this reflex is retained after birth, it can be
characterised by withdrawal, reticence at being involved in anything
new, fear of different circumstances, and is often described as the
“scaredy cat” child who bears the brunt of teasing by normally
adventurous children.
This behaviour appears to be
due to the reflex’s involvement with the parasympathetic nervous
system.  Most of us are familiar with the “fight or flight” adrenalin
rush of the sympathetic nervous system, however the FPR taps into the
opposing system urging the body to “eat and stay”.  The
parasympathetic nervous system is intimately involved with the vagus
nerve.  This nerve comes directly from the brain to aid the organs.
It bypasses the spinal cord, so in the case of spinal injury we are
still able to digest our food.  The vagus nerve may be mechanically
trapped in the skull, chest, abdomen or neck.  Release of this nerve
entrapment corrects one physical factor that contributes to the
retention of the FPR.


How can I create computer based psychology experiments using OS X? I've used E-prime to create computer based psychology experiments (you know, the kind where you for example show a number of pictures to the participant and record their responses to them, for example keypresses) for Windows. However, I'd now like to create similar experiments in OS X.

If I search Google for this, I find a couple of different hits but it's hard to evaluate the quality of these programs. What's a good program to use for this purpose?

My research group has gone pure python for coding experiments; we've been burned too many times by glitches and implicit behaviour in boxed experiment-building software to bother trusting it. Moving from a point-and-click experiment design interface to pure code does have a large learning curve, and you want to be careful to model your own code on well validated code from others (esp. for ensuring that you're implementing timing properly, which can be nuanced).

It may be tempting to hire CS students to code your experiments, but the danger there is they don't come to the table with the same experimental design background as you do and we've encountered some implementation errors as a consequence (ex. failing to check for input during dead time between stimulus presentation, etc).

While I recognize and indeed support the push to specialization in cognitive science, I do think that in the same way that we require all researchers to have a bit of background in statistics, we should also require all researchers to have a bit of background in coding, not least because it helps engender a mindset amenable to considering formal models of mind.


Do we understand the non-subjective mechanisms behind pleasure and pain? If we are to view pleasure and pain as being essentially synonymous with the more mechanistic concept of reward and punishment (i.e. as a part of learning and motivation system) then do we understand how this actually occurs at a neurobiological level?  At least in "lower" animals, pain seems to simply cause an aversion response. Pain motivates the animal to stop whatever it was doing (possibly stopping the pain), and to avoid in the future repeating similar responses to those that preceded (and therefore were possibly causal toward) the incident that caused pain.

This sort of thing is not that hard to replicate in computational models, so it is clearly nothing magical.  Obviously, the subjective "experience" of pleasure and pain gets more into philosophy of mind and that's not what I am asking about. I am only concerned about the mechanism which can explain outwardly observable behavior -- especially in simpler animals -- such as the basic stimulus-response-reward/punishment learning that a mouse or bird can do.

Do we understand the mechanism by which a pain signal causes the brain to suppress recently followed decision paths, and a pleasure signal causes the brain to reinforce them?  Or is this still completely mysterious at this time?

I think part of the answer to your question is going to include the dopamine "reward" pathway in the basal ganglia. In particular, a leading theory of dopaminergic function is the predictive reward error or reinforcement learning hypothesis. In this theory, dopamine neurons signal expectations about the outcome of particular stimuli.

Some key experiments are outlined in Schultz, 1998 (PDF). First, an unexpected reward elicits a short activity increase in dopamine neurons. Second, if a conditioned stimulus (CS) precedes the reward, the dopamine neuron fires in response to the CS but not the reward. That is, the dopamine signal is now a predictive reward signal. Third, if the CS is presented and then the reward does not occur, the response to the CS occurs but the dopamine neuron depresses activity immediately after the reward should have happened.

So the theory goes that dopamine neurons are not simply saying whether a reward has occurred, but rather as a learning signal that adjusts predictions about rewards. If an unpredicted reward occurs, the neuron signals a positive error ("Oops, that was a reward I should know about!"). If a predicted reward occurs, the neuron signals no error at the time of the reward ("shrug, I knew that was going to happen"). If a predicted reward does not occur, the neuron signals a negative error ("Aw shucks, guess that bell doesn't mean food after all.").

A somewhat updated revision of the theory is outlined in a review by Redgrave and Gurney, 2006 (PDF). Importantly, they note that dopamine neurons suppress their activity in response to noxious stimuli (the pain aspect of your question). They also raise some tough questions about how exactly this dopamine signal interacts with other parts of the brain to mediate the learning suggested in the theory.

As with basically all neurobiology theory, a full understanding of how this signal that we detect in individual neurons translates into a coherent behavioral response program is a long ways away. But the basal ganglia, in general, are sometimes thought of as an action selection system (or "decision path" selection to use your words), so the ability of dopamine neurons to signal expectations is relevant.


Biases in subjective survey What are the commonly observed biases in survey and are there any statistical or non-statistical methods to avoid it?

I am conducting a survey for automobile seat comfort, I think my current methodology may have following issues :

Subjects may give average rating when they are unsure

Subjective rating may be anchored on the first vehicle subject sits in

There are lots of commonly observed biases in surveys, and a whole field of survey methodology and statistics which investigates them. To get an idea of this, take a look at the table of contents of these journals:
http://poq.oxfordjournals.org/content/current
http://jssam.oxfordjournals.org/content/current

Many people in this field are dealing with large data-sets (e.g., national censuses with many thousands of respondents), and they concentrate on things like estimating non-responses statistically (to take into account that some people with some opinions are less likely to complete the survey in the first place). Other widely investigated biases include "social desirability", which is the issue that people often respond with what is most social acceptable, even if it is not necessarily accurate.

However, your question suggests you are looking on a smaller scale. Although it is a bit old, this is a nice review of cross-overs between psychology and survey statistics. Not sure if the full article is stuck behind a paywall. This covers some similar ground.

RE: Your first identified issue, I assume that by "average" rating, you mean that people tend to choose the middle scale point if they are unsure (obviously they don't normally know the true average/mean response from their peers). There is evidence of this (see the Schwarz article above). From the abstract of Schwarz et al., 1985:

  These results indicate that subjects inferred the average amount of
  television watching from the response alternatives provided them and
  used it as a standard of comparison in evaluating their behavior and
  its implications.

What this means is that you should be a bit careful about choosing your scale (people will use the end points to evaluate what the average rating is). However, normally you are interested in relative deviations from this (which seats are rated higher or lower than average relative to other seats), so this is an issue only if you are seeking a "real number" answer (such as the number of hours people watch TV). One way to counteract the "centering" bias is to use a 4 or 6-point scale rather than an odd number (so that there is no exact centre option) A related issue is that people are often reluctant to choose the most extreme options ("endpoint bias"). The wiki on Likert scales has some information about this, assuming you are using such a scale.

RE: Your second issue, yes, question order matters. People often spend less time and respond differently on later questions (e.g., this paper). The specific issues of anchoring responses are discussed here. However, In your case this should be easy to control for by randomising the order in which they sit in the vehicles.


When a person is unable to recognize their own emotions, what is the name for it? What is the name for inability to recognize one's own (not other's) emotions?

Are you referring to alexithymia?

Alexithymia is defined as a personality construct characterized by the sub-clinical inability to identify and describe emotions in the self. The core characteristics of alexithymia are marked dysfunction in emotional awareness, social attachment, and interpersonal relating. Furthermore, individuals suffering from alexithymia also have difficulty in distinguishing and appreciating the emotions of others, which is thought to lead to un-empathic and ineffective emotional responding.

Source: https://www.disabled-world.com/health/neurology/alexithymia.php


How to train our brain to see everything in slow motion? People who had near death experience often found that they were able to see everything in slow motion and capture every details in their surrounding at that particular period. Because the brain process a lot of information at that time due to adrenaline in the blood to aid our chances of survival. So is there a way to train the brain to increase its processing capacity so we can perceive things like mentioned above all the time.

Here is an article that explains that the time warp during near death experiences is an illusion. http://www.livescience.com/2117-time-slow-emergencies.html In such situations, the mind captures more memories of the event. "And the more memory you have of an event, the longer you believe it took."


How does my spinal cord know to take reflexive action? As in, how does my body know that a stove is not hot enough to warrant a reflex? Is it because there isn't a sudden electrical surge going through the nervous system?

It's not that your body knows, exactly, but that one's body is wired in such a way to support reflexes. There is a sudden electrical surge (electrochemical, actually) but it's more compartmentalized than "the nervous system."

Divide the nervous system in two: we've got one section containing our brain and spinal cord. That's called the central nervous system, or CNS. Everything else is our peripheral nervous system, called the PNS.

I'll use the stretch reflex because it's the one I'm more familiar with, but the same goes for all spinal reflexes. Our muscles actively contract, and we need a mechanism to make sure they don't extend past a certain point. The stretch reflex is such a mechanism: when that rubber hammer hits the tendon below the kneecap, the thigh muscle gets stretched. In turn, this causes the knee-jerk reflex as that muscle gets a sudden jolt of "oh my god we don't want that to stretch or else we might not be able to run if we need to or it might damage the muscle or..." (you get the idea, surely).

The reflex takes precedence above conscious thought. Usually. How it does this is through bypassing the brain. Think of how it might work otherwise: hm that stove is hot, I need to get away from it? There'd likely be far fewer humans in the world if that were the case. Instead, the surge (called an action potential) travels straight from sensing to action--preserve the organism, then it can think about whatever just happened.

As far as when to jump or not to jump, neurons either fire or they do not, as per the all-or-nothing principle. If there's enough stimulus (if it's hot enough), then that'll happen.


What does fMRI data look like after pre-processing? I wish to know what fMRI data looks like after preprocessing.

My Understanding

My understanding is that fMRI is MRI in time dimension that is we have repeated scans of brain volume. A voxel is a unit if measurement in fMRI because BOLD signal is measured on a typical voxel in different regions of the brain using gradient of the High frequency signal.

For example if we have fMRI scans say of D ADHD patients, V voxels and T time points in a fMRI study then how the fMRI data after pre-processing would be arranged in a matrix form.

If we assume that it is organized in D x V x T then we have a 3D scan of each brain on a time dimension. Since each 3D scan consists of voxels in the brain, and voxels are cubes that have 6 values around them, then where are those 6 values?

If a voxel is a cube, does it have a single value, or 6 potentially different values on each face? I know voxels have coordinates like that in the MNI coordinate system.

The MRI signal is a small electrical current induced in the receiver coil by the precession of magnetization during resonance, i.e., a manifestation of Faraday's Law of Induction, wherein a changing magnetic field induces a voltage in a nearby conductor. The BOLD response often used in fMRI measures the hemodynamic response, i.e., the relative levels of oxyhemoglobin and deoxyhemoglobin that can be detected on the basis of their differential magnetic susceptibility.

As any digital signal, there are limits to the resolution of fMRI, and is dependent on a number of factors (Kashou, 2014), including the field of view (x- and y- directions) and the slice thickness (z-direction). Multiplying the x, y and z sizes results in the total voxel size (Fig. 1). each voxel has 1 value, namely its respective BOLD response signal value.

Reference
- Kashou, A Practical Guide to an fMRI Experiment, Intech Open Science (2013)

Fig. 1. Time series of fMRI. source: Principles of fMRI


Do we have a predisposition to view visual stimuli in a clockwise pattern? I understand that we typically view the center of the image first and then are likely to move on a horizontal axis, but is there evidence that we tend to follow a clockwise path when viewing more complex visual stimuli?

Alternatively, for individuals who speak languages that are read and written from right to left (Urdu, Hebrew, etc.), is there evidence that they tend toward a counterclockwise visual path?

Abed, 1991 found cultural differences in visual scanning patterns that seem to reflect differences in the languages of the cultural groups.

Individuals from cultures with languages than may be read vertically as opposed to horizontally tended to have more vertical eye movements than individuals from cultures with horizontally-read languages.
Individuals from cultures with languages that are read right-to-left tended to show more right-to-left eye movements than individuals from cultures with languages that are read left-to-right.

Abed, F. (1991). Cultural influences on visual scanning patterns. Journal of Cross Cultural Psychology, 22(4), 525-534. Link to article.


Physiology behind EEG measurements Many questions were asked about general procedures of Electroencephalography (EEG), which were phrased in a rather specific context. Not only were these questions hard to find, they might also be difficult to generalize for novices. This was discussed in this meta-post. Providing a more generalized context could make the information more accessible. Therefore:

What is the physiology behind EEG measurements and how is this recorded?

EEG research all started with Hans Berger, who in 1929 reported that brain activity could be recorded by measuring electrical activity on the scalp. Although the notion of ‘brain waves’ that were found by Berger was controversial, over the years many researchers replicated the results, which led to the acceptance of EEG as a real phenomenon.

Neurons
Before going into all the different ways of analyzing EEG data, let us first try to understand the brain and how brain activity is generated. Let us therefore look at one of the smallest units in the brain: the neuron. Each neuron has a resting potential of 75 millivolts, meaning that the there is a difference in electrical potential of 75 millivolts between the inside of the cell and the outside. This resting potential is maintained by the Sodium-Potassium pump, by ensuring that there is a high concentration of sodium (Na+) outside of the cell, and a high concentration of potassium (K+) inside the cell.

The neuron can be stimulated by an external electrical potential, which will cause the permeability of the cell wall to change. The Na+ and K+ ions are then temporarily free to move through the cell wall, such that the concentration of Na+ and K+ will be the same both inside and outside of the cell. Accompanied with this free flow is a huge increase in voltage, which is also referred to as an action potential. This action potential will be propagated through the axon to the synapses, which will release neurotransmitters outside of the cell. These neurotransmitters will, in turn, attach to a receptor site at the dendrites of a new neuron, thereby changing the permeability of that neuron. Again, charged ions will flow into that cell, which will result in post-synaptic potential. This potential can be either inhibitory or excitatory. Thousands of synapses can be related to one dendrite. When enough excitatory post-synaptic potentials (EPSPs) occur simultaneously from these synapses, a new action potential can occur in the new neuron.

Electrical fields
The influx of ions at the dendritic side of a neuron, as the result of an EPSP, will result in a negatively charged extra-cellular space, relative to the axon-side of the neuron. This is especially interesting for a pyramidal cell, where the axons and dendrites are clearly separated (See Figure 1; left). Because of this orientation, a dipole will come to exist. A dipole is when a positively charged area is close to a negatively charged area which creates an electrical field: a space surrounding an ion in which force is exerted on other ions (See Figure 1; right). “When a large number of small dipoles, such as those generated by activity in a pyramidal cell, are summed together, the resulting electrical potential can be described as a single, larger dipole referred to as an ‘equivalent current dipole’ (ECD). The ECD has an orientation equal to the average of the orientations of the smaller dipoles” (Dickter and Kieffaber, 2014).

Measuring EEG
The geometry of the pyramidal cells is not all that makes the electrical fields measurable. The orientation is incredibly important. As stated earlier, the electrical fields have the same orientation as the pyramidal neurons (See Figure 1). If the pyramidal cells are perpendicular to the scalp, the electrical fields will be so as well. The electrical fields will then point ‘outwards’ and thereby affect the potential at the scalp (See Figure 2, right). This is what is recorded with EEG. Conversely, when the pyramidal cells are in parallel with the scalp, the electrical fields will be so as well, and therefore will not reach the scalp (see Figure 2; left) and will not be measureable.

The extent to which the electrical fields are summed, depends on the spatial and temporal contiguity of the pyramidal cells. Neurons that are closer together will have a higher summation than two neurons that are far apart. Although the human body is full of fluids and electrical flow can be conducted throughout it, the effect will diminish when the distance increases.

So now we know where the signal comes from. But how is it recorded? Well, an EEG cap contains electrodes, which are “connected” to the scalp by use of a conductive gel. This gel contains free ions that are able to move freely which, therefore, allows the gel to conduct the biological signal. The signal is then conducted to the metallic electrode through “redox (oxidation-reduction) reactions”, which is the interchange of electrodes between the gel and the metal of the electrodes. When considering Silver-Chloride (AgCl) electrodes, Cl- ions can be removed from the silver and, conversely, Cl- can be bound to free Ag+ ions, thereby creating the compound AgCl. This changes in the metal will then be conducted through the cable to the systems.

Analog Digital Conversion
At this moment, the signal is still analog, that is, a natural occurring signal that can have any natural value. The computer however, is nog capable of measuring analog values. Instead, the analog signal must be converted to digital values, such that it can be represented in bits (ones and zeros). This is done by taking a range of voltages that you expect to be measured, and divide that by the amount of bits that the system can take (see Figure 3)

Extra Note

EEG can only measure the activity of pyramidal cells that are perpendicular to the scalp and at the surface of the cortex. Are the other pyramidal cells then just lost? Not really. Another really neat property of electrical flow is that it creates a magnetic field that is perpendicular to the dipole (See Figure 4). For the magnetic field to “move out of the head”, making it measurable, the pyramidal cells must lie parallel to the scalp. Magnetic fields also do not need conductive tissue to be measured. This can be recorded with magneto-encephalography (MEG). MEG is thus a perfect complement to EEG, although deeper positioned structures can still not be recorded.

References

Luck, S. J. (2014). An introduction to the event-related potential technique. MIT press. ISO 690
Dickter, C. L., & Kieffaber, P. D. (2013). EEG methods for the psychological sciences. Sage.


IQ Test stability longitudinal study I am wondering if someone could direct me to a longitudinal study examining IQ test scores over time. For example, testing a group of test subjects every 10 years from age 5 to age 65.

The reason I am looking for such a study is I am interested to know what proof there is or is not that IQ is stable over time. It seems to me that it is accepted that IQ should be stable over a lifetime, but I haven't found any study that demonstrates this.

If we assume that IQ is the result of genetics and early childhood environment, then it follows that it should be stable over a lifespan, but I am looking for a study that demonstrates this through repeated IQ measurement over the lifespan.

I'll just give a bit of background about what I understand about IQ below:

IQ is obviously not an exact measure. It's reasonable that a person's measured IQ could vary by around +/- 6 IQ points from their true IQ, therefore it is still a stable measurements if all IQ measurements over a lifespan are within a 12 point range.
Brain damage such as catastrophic injury or regular alcohol abuse can permanently lower IQ.
During adolescence there has been shown to be greater than normal fluctuation in IQ. I would suppose that, because IQ is a measure against age peers, the wide differences in maturation for individuals in the adolescent age range account for the fluctuations in IQ. However I would be interested to know if there were studies that showed children's IQs to have permanently raised or lowered during adolesence.
If an individual has difficulty with an IQ test not related to raw intellegence, for example, if they have ADHD and therefore difficulty concentrating, then treating their issue may allow them to score higher on an IQ test than prior to treatment. In these cases it would seem that the condition masked their intelligence, and treatment did not improve their intelligence but allowed it to be measured more accurately. The same could probably be said of an individual for whom cultural biases in an IQ test (eg with verbal knowledge) worked against them.

There are some subtleties to this question which you may or may not realize. There are (at least) two similarly sounding questions, but they are actually quite different questions:

Does an individual's general cognitive abilities change throughout life?
Does the rank-order of a population's cognitive abilities change throughout life? In other words, if we test a population at one time and then again at another time, will those who scored highly on the first test also be the ones who score highly on the second test and vice versa?

The answer to the first is trivially yes. An individual's brain is more powerful and has learned more when they are 22, then when they are 4, say. There is also reduction in cognitive abilities when people become elderly.

The second question is more interesting. For this I would refer first to the paper:

Deary et al (2000). The stability of individual differences in mental ability from childhood to old age: Follow-up of the 1932 Scottish Mental Survey. See pdf here.

They conclude that

  The correlation between Moray House Test scores at age 11 and age 77 was 0.63, which adjusted to 0.73 when corrected for attenuation of ability range within the re-tested sample. This, the longest follow-up study of psychometric intelligence reported to date, shows that mental ability differences show substantial stability from childhood to late life.

So the rank-order of abilities within a population probably correlates >0.7 with its rank-order six and a half decades later (age 11 to age 77).

Another interesting study, which is new and I don't believe is published yet, is the following:

Grønkjær et al. Associations between education and age-related cognitive changes in a 41-year follow-up study

In this Danish longitudinal study, they have them first tested at mean age 20, then again 41 years later at mean age 61. They report finding:

  The mean change in BPP test scores was -2.94 (SD 5.60) and a retest correlation of 0.81 between the baseline and follow-up BPP scores was observed.

These correlations are not quite in the 0.9-1.0 range, and hence we're certainly not seeing perfect stability. On the other hand, I don't think I know any quantitatively measured psychological trait which shows a greater longitudinal stability (in terms of rank-ordering) than general cognitive ability.


Pros and Cons of PsychoPy for designing psychological experiments? What are the advantages of using PsychoPy for making an experiment (beyond the fact that it is free and open source)? I do not use psychophysics stimuli (no Gabor for instance); my stimuli are static images or text. Compared to E-Prime for example, how easy is it to set up a basic RT experiment?

I highly recommend PsychoPy over E-prime. Why?

Keeping track of who has the e-prime dongle is annoying.
Students learn it more easily (see data below).
E-prime uses visual basic (boo) and PsychoPy uses Python (yay!).
PsychoPy easily integrates with R, matlab, and HTML.
Everyone is doing it... (see data).

Some folks at UCSD did a survey in summer/fall 2014 asking researchers for their opinions. Here is a summary of the findings.


Why is the initial first-line response to a psychological problem not a brain scan? I get the impression most people having a cognitive problem are encouraged to see either a psychologists or psychiatrists (the actual medical doctors) to
engage in verbal or pharmaceutical therapy. I actually knew someone who, in the '80s, was having visual hallucinations for months and seeing a therapist before she actually got a brain scan and discovered it was a benign tumor.

While I can understand that scans cost money, since repeated therapy sessions also cost money, I don't really understand why the prevailing advice isn't "scan the person's brain first, and check their blood, then try chatting with them if it isn't obvious after that". Wouldn't you want to go with the obvious, empirical objective measures first, and switch to heuristics after that?

Which isn't to say that it isn't important to have an initial conversation with the person- for the same reason a person should have a conversation with their GP- but it seems like that only makes sense as a precursor or supplement to the physical testing that also needs to happen.

The first stop when a non-emergency medical issue evolves is, as you say, a visit to the GP. This is not a supplement to diagnosis. Instead, a visit to the GP can be a critical step in the treatment process and a GP will assess what the most probable underlying cause is during a consultation, based on a physical examination and verbal communications. Then the GP can refer the patient to the proper next medical practitioner for specialized help. Note that a diagnosis involves mainly excluding other causes and narrowing down the list of options.

Your case report lacks some critical information (e.g., age at diagnosis etc.), but the statistics behind the diagnosis can still tell a lot about the GPs decision:

The incidence of brain tumors is about 22 cases per 100,000 individuals (0.02%). Brain tumors are most likely to arise in kids or late teens. Dependent on the age of your friend at the time of diagnosis, this may have placed them out of that age window.
The incidence of visual hallucinations is about 17 per 1000 (1.7%) (Tien, 1991), i.e., orders of magnitude higher than brain tumors. In other words, just a minor fraction of visual hallucinations are caused by brain tumors. A more likely cause for hallucinations are positive psychotic symptoms, the realm of psychotherapists and psychiatrists. Most visual hallucinations are caused by psychosis (e.g., schizophrenia), Parkinson's disease and Alzheimer's disease (source: WebMD). The latter two are typical cheriatric diseases (diseases linked to old age). If your friend was not considered an elderly at the time of diagnosis, it would make psychosis the most likely candidate cause of the symptoms.

Brain scans do not diagnose Alzheimer's or Parkinson's, nor psychosis. A brain scan would only, perhaps, find a tumor that has a very small chance of occurring. Moreover, a single scan may not be enough. The tumor may be small and clinical tests, fMRI, PET, or bone scans may be necessary (source: JHMI), which can result in an extensive list of scans, many hospital visits, and associated financial burden. The GP chose the best hit, and that's a psychiatric issue.

Reference
- Tien, Soc Psychiatry Psychiatr Epidemiol (1991); 26(6):287-92


Is there any "predictive" component to positive/negative affect in Seasonal Affective Disorder and Bipolar Disorder? I'm wondering if the human brain "predicts" how certain weeks of the year should feel?

For example, a child who is going to school may have a more positive affect in anticipation of summer holidays, and may feel more negatively towards the end of the summer, as he/she knows that freedom and fun are about to end.

Another example may be siblings' or parents' birthdays, where the anticipation of the birthday increases positive affect.

I'm wondering if year after year of such patterns (in childhood, the teenage years and maybe young adolescence) can create an association in the brain between positive/negative affect and the specific time of the year, or specific photoperiod duration (day length). What I'm trying to understand is, if a pattern of such ups and downs that may have been established in the childhood persists throughout adulthood?

Have there been any studies that looked at the previous life history and incidence of mania/depression episodes in bipolar disorder, or the onset of depression in Seasonal Affective Disorder(SAD), and correlated them with holidays, birthdays, etc? I've read that SAD may manifest a depression in any season, not just winter, which got me thinking of the possible causes.

I found the term "holiday anniversary  memory triggers" on a popular psychology website. It clusters a lot of symptoms together:

http://outofthefog.website/top-100-trait-blog/2015/11/4/holiday-anniversary-memory-triggers


Why do difficult-to-learn subjects seem easier in retrospect? Background: I have recently noticed that in class, that after I finished a unit, it seems less difficult than I expected it to be. It has happened in math, physics and electronics.

Is it possible that maybe those units were not even difficult in the first place? That it was just  a matter of perception and first judgement, where you think to yourself "Oh lord, this unit is gonna be hell," and the mind plays along with that all through?

Why do difficult-to-learn subjects seem easier in retrospect?

There are at least two different lines of research that are relevant here.

Forecasting errors

One large line of research has shown that are pretty bad in forecasting future events. This can be seen, for example, in the stable tendency to overestimate the affective impact of negative as well as positive events in terms of intensity and duration. In other words, if people are facing a situation that will likely be negative (such as an "it will be hell" class or exam), the prediction of their negative affective reaction (How long intense will it be? How long will I suffer?) is stronger than their actual reaction. This tendency has been called the impact bias. Numerous sources of the impact bias have been identified, a good starting point into this research are the (somewhat older) reviews by Wilson and Gilbert (2003, 2005). As an example, one reason for the impact bias in response to negative events is the so-called immune neglect, which refers to people's tendency to underestimate their skill in coping with such events.

Below-average effect

It is also possible to frame the situation in a way that implies a comparison to others: Maybe you expected a difficult class in that you expected to fare worse than your fellow students (and were surprised that you were not).

A line of research has shown that people can be pretty bad in ranking their own skill in comparison to others. Mostly, this surfaces in an above-average effect: Most people think that they are better drivers than others, for example, which is logically impossible. However, research by Justin Kruger (1999), for example, has shown that this holds only for relatively easy tasks. For difficult tasks, this actually turns into a below-average effect. That is, when people think that a task requires much skill (such as a difficult class or exam) most actually think that they are worse than other people. One explanation for this tendency is that people "anchor" their judgment of their own skill only on their introspected self-assessment and fail to consider that it will be difficult for others too (information about ourself comes more easily to the mind, after all).

References

Wilson, T. D., & Gilbert, D. T. (2003). Affective Forecasting. In M. P. Zanna (Ed.), Advances in experimental social psychology (Vol. 35, pp. 345–411). San Diego, CA: Academic Press.

Kruger, J. (1999). Lake Wobegon be gone! The “below-average effect” and the egocentric nature of comparative ability judgments. Journal of Personality and Social Psychology, 77, 221–232. doi:10.1037/0022-3514.77.2.221

Wilson, T. D., & Gilbert, D. T. (2005). Affective forecasting knowing what to want. Current Directions in Psychological Science, 14, 131–134. doi:10.1111/j.0963-7214.2005.00355.x


Are there gender differences in color discrimination ability? There appears to be a prevalent stereotype that girls seem to have "heightened" color perception. By this term, I mean that they can identify the salient features of different shades of color. However, many ideas that are widespread in public consciousness do not seem to be based on empirical evidence.

Is there any research that has investigated gender differences in color perception? In particular, are there any well-performed experiments in the study of perception or cognitive neuroscience that may shed light on this perceived phenomenon?

There are many 'sources' on the internet that seem to have commented on this, but I can't find any compelling evidence personally. There is some literature on cross-cultural variation and cross-language perceptual differences, is there any literature on cross-gender variation?

Sources:

Jameson, K. A., Highnote, S. M., & Wasserman, L. M. (2001). Richer color experience in observers with multiple opsin genes. Psychonomic bulletin and review, 8, 244-261.

Gilbert, A. L., Regier, T., Kay, P., & Ivry, R. B. (2006). Whorf hypothesis is supported in the right visual field but not the left. Proceedings of the National Academy of Sciences of the United States of America, 103(2), 489–494.

Short answer: A recent study suggests that, if you rigorously restrict the sample to normal vision participants, women do not outperform men in color discrimination.

Long answer:

As @what has pointed out with the link to Google Scholar, there are a number of studies that have investigated sex differences with regard to color vision.

However, if one accounts for the fact that there are more men who have a deficiency in color vision (because they have only one X chromosome which is involved in color vision), the differences appear to be small and may even contradict the stereotype.

I found one study (Rodríguez-Carmona, Sharpe, Harlow, & Barbur, 2008) that seems particularly close to your specific question. Citing from the abstract (emphasis mine):

Background

  Generally women are believed to be more discriminating than men in the use of color names and this is often taken to imply superior color vision. However, if both X-chromosome linked color deficient males (8%) and females (<1%) as well as heterozygote female carriers (15%) are excluded from comparisons, then differences between men and women in red-green (RG) color discrimination have been reported as not being significant (e.g., Pickford, 1944; Hood et al., 2006).

Study Goal,  Method, and Sample

  We re-examined this question by assessing the performance of 150 males and 150 females on the color assessment and diagnosis (CAD) test (Rodriguez-Carmona et al., 2005). This is a sensitive test that yields small color detection thresholds. The test employs direction-specific, moving, chromatic stimuli embedded in a background of random, dynamic, luminance contrast noise. A four-alternative, forced-choice procedure is employed to measure the subject's thresholds for detection of color signals in 16 directions in color space, while ensuring that the subject cannot make use of any residual luminance contrast signals. In addition, we measured the Rayleigh anomaloscope matches in a subgroup of 111 males and 114 females.
  All the age-matched males (30.8 ± 9.7) and females (26.7 ± 8.8) had normal color vision as diagnosed by a battery of conventional color vision tests. Females with known color deficient relatives were excluded from the study.

Results

  Comparisons between the male and female groups revealed no significant differences in anomaloscope midpoints (p = 0.709), but a significant difference in matching ranges (p = 0.040); females on average tended to have a larger mean range (4.11) than males (3.75). Females also had significantly higher CAD thresholds than males along the RG (p = 0.0004), but not along the yellow-blue (YB) discrimination axis. The differences between males and females in RG discrimination may be related to the heterozygosity in X-linked cone photo pigment expression common among females.

What does this mean?

Citing from the conclusion of the paper

  Chromatic sensitivity was measured in a large population of normal trichromat males and females (...). On average, females were revealed to have significantly higher RG chromatic thresholds compared with men on
  the CAD test and larger red-green matching ranges on the Nagel anomaloscope. A correction was applied to exclude the possible effect of female heterozygotes that were undetected by our screening procedures upon our gender comparisons. On the basis of our results, we can confidently conclude that women do not have superior red-green colour discrimination than men. However, the possibility arises that they may on average have poorer discrimination. Genetic and physiological explanations related to a sexual dimorphism in X-linked cone photopigment expression are offered as to why this may be the case.

References

Rodríguez-Carmona, M., Sharpe, L. t., Harlow, J. a., & Barbur, J. l. (2008). Sex-related differences in chromatic sensitivity. Visual Neuroscience, 25, 433–440. doi:10.1017/S095252380808019X


Tests of Semantic Memory suitable for 10 to 18 year old I'm trying to find a test of semantic memory for students.

We're working on a programme to explore the impacts of exposure to nature on a student's academic abilities (hoping to pique teachers interest by showing the interconnection).

The starting point for this was this paper in which students that are taken for a walk in the park experience a boost in working memory. The test used there was a reverse digit sequence recall.

I'm looking to use a different test that is more closely related to semantic memory, and if possible, is a little less dull (I know ideally this would not be a factor, but I suspect some will think the digit sequence test too simplistic and dismiss the results as not representative of aptitude on more complex challenges of school subjects).

My understanding of the different types of memory is that semantic is the one that makes up a big component of what is tested on traditional academic standard tests, so this would be a more relevant fit to showing the relationship between nature and the cognitive abilities commonly valued and assessed.

In looking for tests, I found the NIH toolbox, but it only has tests on episodic and working memory.
I've also looked here on StackExchange, but again, can't find answers specific to semantic memory.

Where might I look for an appropriate tool for semantic memory?
If the test is one that can be administered to the same student more than once, that would be helpful too (to show comparative difference in memory after exposure to different environments)
(and if you have suggestions of other cognitive skills that we should be examining, I'm open to it)

This seems difficult for a number of reasons.

First, are you interested in testing the retrieval of pre-existing semantic memories or the ability to form new semantic memories?  It is entirely possible that exposure to nature increases one without the other, so be sure you're testing the one you're interested in (or both, carefully).

Second, semantic memory is highly dependent on environmental exposure (e.g., I know that trains in the Netherlands are blue and yellow, but if you haven't been there, you probably don't), and thus creating an appropriate semantic memory task will vary by demographic (much more finely cut than "10-18yo"), location, etc.  This means that a general test of semantic knowledge is unlikely to be valid over a large set of the population.

Third, semantic memory is extremely susceptible to practice effects (otherwise studying wouldn't work), so figuring out something that can be administered more than once without major order effects is unlikely.  You will probably have to find a task and split it into subsets which can be administered at different times, which will compound your demographic problem above by requiring more items.

If you want to test ability to encode semantic memory, the task in a paper like McKoon & Ratcliff (1986) may be helpful.  If you want to test the ability to retrieve pre-existing semantic memories, something like that used in Patterson et al. (2014) would be more useful.  You may want to repurpose either procedure by substituting scholastically relevant facts for their category recognition and/or new encoding tasks.

Automatic activation of episodic information in a semantic memory task.
McKoon, G., & Ratcliff, R.
Journal of Experimental Psychology: Learning, Memory, and Cognition, Vol 12(1), Jan 1986, 108-115. http://dx.doi.org/10.1037/0278-7393.12.1.108

Semantic memory: Which side are you on?
Patterson, K., Kopelman, M., Woollams, A., Brownsett, S., Geranmayeh, F., et al. Neuropsychologia (Nov 22, 2014). http://dx.doi.org/10.1016/j.neuropsychologia.2014.11.024


Is Elizabeth Holmes having a psychological disorder? Elizabeth Holmes CEO of Theranos is charged with massive fraud. I'm watching her interviews on YouTube from her rise to her fall. On YouTube comments sections, some people say she's a psychopath and some say she's a sociopath, usually without providing strong argument. Is it safe to say that she's got psychological disorder without any mental health investigation?

Welcome to Psychology.SE! For a number of reasons outlined in this meta post we can not, and will not, give advice for any individual. Therefore, if you was seeking advice for yourself or a friend, this question would be off-topic.

One of the reasons is that we cannot properly diagnose any psychological disorder here. The same will be said for the person in your question.

Forde (2007) highlights the following concerning assessment techniques:

reliability means

  the extent to which a test consistently measures the same thing,

validity is

  the extent to which the test measures what it is intended to measure

a test

  cannot be valid if it isn't also reliable

any form of assessment

  (and not just a traditional pencil and paper test) must be both valid and reliable, or it is useless.

With this in mind, you cannot say anyone has a psychological disorder without a valid and reliable method of diagnosis (Forde, 2017).

In other situations where someone says someone has a psychological disorder, they can be situations where they are voicing possible but not confirmed psychological disorders, which are personal opinions, which cannot be taken notice of officially without the necessary valid and reliable assessment(s).

References

Forde, R. A. (2017). Bad Psychology: How Forensic Psychology Left Science Behind. Jessica Kingsley Publishers.


Does the structure of consciousness mimic that of the visual process? It seems to me that the structure of the conscious mind has some strong similarities to the way our visual field functions. The visual field has a strong and detailed
focus at the center, and this is what generally commands our attention,
while at the same time the visual resolution decreases outward from that
center and its content occupies less of our attention, to the point that
our peripheral vision will alert us to movements but has little to do
with what we are recognizing consciously.

This is similar to the way we think. We have a central focus,
which is the conscious thought, but that object of thought has many
associations or links to other thought objects, and they form a ring
around the focus, just out of view (ie. in the immediate unconscious
zone). Those primary associations also have their own associations
that form a secondary ring, deeper into the unconscious, with further
rings extending outward representing decreasing levels of action
potential.

It makes sense to me that the conscious mind would be patterned on the
functional model of the visual field which is much older and more
fundamental.

Thus, my question: Does the structure of consciousness mimic that of the visual process?

You are describing an observation as old as Freud, where he divided human's experience into three levels, roughly along the same lines as you. The conscious as that clear and ill-defined concept that gives you the feeling of attention, awareness, and self. The preconscious as the level just outside of your current awareness but that could easily spring to your consciousness. Finally, the unconscious, which is a level that doesn't have an analogy in vision: it corresponds to experiences that cannot come to your consciousness but that still affect your behavior.

Unfortunately, this correspondence does not extend beyond analogy, for several reasons. From the point of view of introspection -- the oldest and arguably still only reliable method for studying consciousness -- it is not clear how you would distinguish the visual sensation of attending stimuli from the conscious. In particular, it is not at all clear that the experience you describe as visual is an artefact of the visual system and not consciousness itself. The reason to believe that this is a feature of consciousness and not the visual system is because you experience the same things for hearing, touch, and to-a-lesser-extent smell.

Moving onto the scientific basis is much more difficult, in particular, you write:

  It makes sense to me that the conscious mind would be patterned on the functional model of the visual field which is much older and more fundamental.

This to me seems like an unjustified assertion. Although we have some neurological models of consciousness, none of them are at the level where where we can start to date them on an evolutionary scale.


Are imprinting and computer literacy connected? I've recently became aware of the phenomenon of imprinting, in which baby animals start to associate with the first moving object with eyes that they see during a critical period of their infancy.

What interested me is that at the end of the imprinting article there is a snippet on the "baby duck syndrome" for humans:

  In human–computer interaction, baby duck syndrome denotes the tendency
  for computer users to "imprint" on the first system they learn, then
  judge other systems by their similarity to that first system.[9] The
  result is that "users generally prefer systems similar to those they
  learned on and dislike unfamiliar systems."[10] The issue may present
  itself relatively early in a computer user's experience, and has been
  observed to impede education of students in new software systems.[11]

I'm interested if imprinting affects our ability to interact with computers, and if there is a "critical period" for learning computers.

For example, I repeatedly observed people in their 50s and above, who have not had any exposure to computers until their late 40s, fail to figure out how to operate a computer. A typical example is a bewildered user who has 2 monitors connected and is unable to comprehend or recall that a file can open on a monitor that is turned off, but is connected by cable. A "digital native" would be able to identify such issue in seconds. Is imprinting causing the difference between the experience of these two groups?

The answer is no. Definition of imprinting is:

A rapid learning process by which a newborn or very young animal establishes a behavior pattern of recognition and attraction towards other animals of its own kind, as well as to specific individuals of its species, such as its parents, or to a substitute for these. Ducklings, for example, will imprint upon and follow the first large moving object they observe. In nature, this is usually their mother, but they can be made to imprint upon other moving objects, such as a soccer ball.

Imprinting is not connected to learning social skills but attachment. Also the problem of learning of computing is matter of fluid, crystalized inteligence and anxiety are better predictors:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1524856/


What are the advantages of 2AFC in a psychophysical discrimination task? As far as I understand. In the task of Two alternative forced choice (2AFC), given two possible stimuli, $S1$ or $S2$, the subject has to decide weather he\she (it) saw the sequence $(S1,S2)$ or the sequence $(S2,S1)$.

My question is, what are the advantages of this method over the simple one, in which the subject has to decide weather he saw the stimulus $S1$ or stimulus $S2$.

What makes a task a two alternative forced choice task?

I am beginning my answer with this question because there is a general misconception about what 2AFC really means. Many people believe that 2AFC refers to any task where subjects are asked to select one of two options (yes/no, old/new, bright/dim). However what defines it instead is that there are two stimuli presented on each trial.

Your definition can be thought of as an example of a interval-2AFC (AKA temporal-2AFC), but your example is not a typical 2AFC paradigm. It is true that both s1 and s2 are presented prior to the decision, however, typically (in my experience) subjects only respond about one of the stimuli (like my examples in the figure above). That said, the important distinction is that in a true 2AFC task, subjects are presented with two stimuli per trial. Whenever subjects are judging a single stimulus per trial it is considered a discrimination task or a detection task (e.g., judging the direction of motion in a random dot kinematogram).

Pros and Cons of Detection and 2AFC Tasks

The most cited reason for using the 2AFC procedure is that it is unbiased. For example, in my gender discrimination task (presented in the leftmost panel of the figure), a participant could be biased to respond male more so than female. But in the 2AFC version of the task, the participant is choosing a spatial location (left/right) or an interval (1st or 2nd), so any bias they have about gender is eliminated from the decision. If bias is reduced or eliminated it has the added benefit of rendering assumptions necessary for signal detection models obsolete (e.g., that underlying distributions are gaussian).

A second reason for using 2AFC is that there is a performance enhancement resulting from the fact that participants are provided with more information on each trial. That is, in one case you are presented with a single face and must decide which distribution it comes from, which is harder than being presented with one face from each distribution and having to judge which face belongs to the target distribution.

As for the cons, the aforementioned pros may not be true at all. For that discussion I point you to this 2008 paper by Yeshurun, Carrasco, & Maloney.

Ultimately the better procedure will depend on what your question is and what assumptions you are or are not willing to make.


Is there a way to use a STDP learning rule on rate-based neurons? STDP (spike timing dependent plasticity) is a learning rule for changing the synaptic weights between neurons.  It is Hebbian-like in that the weight changes depend on the coincidence of pre- and post-synaptic spikes, but it includes a notion of causation in that the synapse is strengthened if a presynaptic spike precedes a postsynaptic spike, but the synapse is weakened if a postsynaptic spike precedes a presynaptic spike.

Rate neurons are often used in simulations because they are computationally cheap compared to simulating spiking neurons.  In order to implement STDP, spikes are generated using an inhomogeneous Poisson process with the rate parameter defined by the current rate of the rate neuron.

What I would like to know is whether a shortcut has been developed to calculate the weight changes due to STDP directly from the temporal dynamics of the pre- and post-synaptic weights without having to explicitly generate spike times through a poisson process.

Any help?

The appropriate way to do this is to find the cross-correlation of the time series of rates of the two neurons.  Then take the dot product of the cross correlation with the STDP kernel (i.e., the integral of the correspondence at each point in the STDP window between how much STDP "likes" cross correlation at that lag and how much cross correlation there actually was at that lag).  This gives a value that, when properly scaled, tells you the amount of weight change that synapse should receive.

In the first panel, the rates of two neurons in a simulation are shown in blue and red respectively.  A zoomed in view is shown (top middle) to emphasize that the blue neuron increases in firing rate slightly before red neuron.  The cross-correlation is plotted on bottom left.  A zoomed in view (bottom middle) emphasizes that the peak of the cross-correlation is slightly negative, corresponding to the fact that the blue neuron leads the red neuron.  We look at the cross-correlation just at lags where STDP is relevant (in this case +/- 100 ms, top right) and there is more correlation at slight negative lags, corresponding to the tendency of the blue neuron to lead.  We then multiply each lag in the cross-correlogram (top right) with the STDP kernel (bottom right) and sum over all relevant lags (between +/-100 ms) to get the value of the synaptic weight change. We can do this because we assume that the likelihood of having a spike lag of a certain amount is proportional to the cross-correlation of the rates at that lag (as probability of spiking is proportional to spike rate).  In this particular case, the weight change will be positive because there is cross-correlation during the positive part of the STDP kernel (lags <0) is greater than the cross-correlation during the negative part of the STDP kernel (lags >0).


Why use a quasi experimental design when you can do an experiment? I read about quasi-experimental design and the variations it has such as pre-test post-test non-equivalent groups, and also experimental designs. Having compared these two, I ascertained that the difference between this variation of quasi-experimental design(pre-test post-test non-equivalent groups) and experimental design is randomization.
However, what I couldn't understand was:

Why should quasi-experimental design  even exist when we can do randomization easily and the randomization has more benefits than matching the participants?

Honestly, I search for the answer but I couldn't find any, and obviously
that is why I'm asking a question, yet if you find any alike question I would be happy if you refer me to it.
I genuinely appreciate it if you refer me to at least one resource as well.
The reference book for the discrimination between these two designs:
Introduction to Research Methods and Data Analysis in Psychology, Third Edition by Darren Langdridge and Gareth Hagger-Johnson

The first paper I found searching for "advantages of quasi-experimental design" was this one:

Schweizer, M. L., Braun, B. I., & Milstone, A. M. (2016). Research methods in healthcare epidemiology and antimicrobial stewardship—quasi-experimental designs. Infection control & hospital epidemiology, 37(10), 1135-1140.

Most of the benefits are pragmatic: less cost, potential for retrospective analysis, bypassing ethical considerations that present barriers to randomized trials, etc.

An example of the type of quasi-randomized design I've often been involved in myself is when the data have already been collected in normal medical practice. Sometimes these patients are difficult if not impossible to consent: an intensive-care unit population, for example. Those patients are very sick and their imminent needs are live-saving care; there may not be time to obtain consent for a randomized trial. However, if practices and policies change over time or are different in different facilities, you can use a quasi-experimental design to determine whether those changes or differences in standard of care have an important impact or not.


What is forward masking I am trying to understand what is visual masking (or more specificaly forward masking). I have read the explanation here, but still..

I understand that a background can interfere with a frontal visual stimulus. Anyone knows that. If I use whithe letters on white page I will see nothing. But, I assume the definition has more then that.. for example, in here, in figure 1b, are they describing an experiment? If yes' then what is the experiment? I mean, what is the stimulus, what is the masking, what is the experiment question, and what is the result (I assume that there are known results to what the figure is describing...)

Thank you!!

Visual masking has quite a few variations, and the source you've linked is by far the worst explanation I've seen.

In forward masking an early stimuli takes hold over consciousness (resulting in top-down activation) that prevents a later stimuli from overshooting the selective attention threshold, thus the latter remains subliminal (limen is threshold in Latin, so sub-liminal is literally below threshold).

For example, in the following frame sequence you'd be asked to find the letters in a sequence of numbers. Given there's less than 100ms between the two targets, your conscious attention to the first target will almost always prevent the second target from being perceived.

For a nice demo of this have a look at this attentional blink test video.

Another variation is to expose a frame for less than 30ms between various pre or post masks.

The principle, however, is always the same - paying attention to one stimuli 'saturates' our consciousness and prevents another from entering it.


do monkeys imitate humans sometimes just for fun? Is it possible that sometimes when monkeys stand up on their two legs they are just imitating humans in order to communicate or have fun?

I can break this down into three questions.

(1) Do monkeys imitate? Do they ever imitate humans?

The answer to these questions is yes, though I don't know if that includes standing on two legs.

(2) Do they do it to communicate?

Well, it is difficult to define what communication and with whom we are interested in here, but monkeys (and humans) do seem to be able to recognise when they are are being imitated. So at least the potential for communication is there.

(3) Do they do it to have fun?

There is plenty of evidence that monkeys "play", and depending on one's definition we can infer that they are having fun. Some play involves imitation.

For example this study by Byrne (2005) is an interesting source for some of the above answers, and in particular the "social mirroring" type of imitation implies some communication and theory of mind. We should also be careful here to distinguish between monkeys and apes, some of these behaviours are disputed in different species.


What's the correct way to use 'schadenfreude' to describe a person who has/uses/suffers from it? There are examples at dictionary.com on uses of 'schadenfreude'.

But what is the correct way to describe a person that has/uses/suffers from schadenfreude as part of a personality disorder/mental illness?

She suffers from schadenfreude?
She's diagnosed with schadenfreude?
She delights in schadenfreude? (probably not as the word itself tells us of the delight)
She engages in schadenfreude?
She commits schadenfreude?

I've no idea how to describe someone's mental illness where the primary symptom of this illness is schadenfreude.

What is the correct way to say this?

Edit:

I see from the comments/answer that the question is wrong - I've asked correctly with more details here:
Term for ASPD Specific for Causing Pain to Others

Schadenfreude is an emotion only the German language has a word for. Put simply it is a person enjoying someone else’s misfortune. It does not matter if its monetary, a divorce, a failed exam, or the person being yelled at by the boss…

Link Definition:https://www.merriam-webster.com/dictionary/schadenfreude

Definitely not a mental illness. (for details on mental illness see ICD-10 Fxx.xy. Link: http://www.who.int/classifications/icd/en/)


Are psychology students more neurotic than the general population? Using the NEO-FFI to measure Big Five personality traits among students from our faculty, we found that students of psychology are more neurotic (t = -2.34, p = .02) and less open (t = 5.98, p < .001) than the general population. Are there published studies that verify these results?

In general, females score higher on neuroticism and psychology students are predominantly female.

In some young adult norms that I've seen in the NEO-PI-3 test manual, females score about two-thirds of a standard deviation higher on neuroticism.

In my experience at the undergraduate level, about 70% to 85% of students are females. For example, in my most recent paper using a third-year Australian undergrad psych sample (n = 393), we had 79% females (Horwood & Anglim, 2018, JHB).

I believe also that neuroticism declines with age ( e.g., https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2562318/ ) and psychology students as with other university students tend to be 18 to 25 or so.

You'd have to look a little further to see whether there are differences after controlling for age and gender differences; i.e., whether there's a deeper reason for any differences.


What causes a person to be curious, inquisitive and explorative? Why do humans (primates) tend to be curious, inquisitive and explorative?

They want to know things that they do not. They explore stuff in an attempt to find something new which makes them adventurous and willing to accept challenges. They tend to be curious about what others are doing and going through, making them inquisitive.

What's the cause of this human (primate) behavior?

We are driven by this need to find answer to our questions.

Many questions arise from one's mind by experiencing new events or feelings, or having to sort out a cognitive dissonance. An example of this would be the need for victims to find the guilty.

  When we can’t immediately gratify our desire to know, we become highly motivated to reach a concrete explanation. That motivation, in Kagan’s conception, lies at the heart of most other common motives: achievement, affiliation, power, and the like. We want to eliminate the distress of the unknown. We want, in other words, to achieve “cognitive closure.”
  http://www.newyorker.com/online/blogs/elements/2013/04/why-we-need-answers.html

Going further, there is an intimate relationship between open mindedness and curiosity. Someone thinking he knows it all will never seek for new information or experiences; he will probably stick to denial to protect his intellectual integrity, his homeostasis. Most religions are providing a preconceived cognitive model to answer all that is beyond our understanding.

Skepticism is also correlated to curiosity, as it reopens questions many thought answered for years and it's the base of scientific research. Like Scott Peck (and probably many others) said, science is the religion of skepticism.

And I must say, the feeling of satisfaction is a great motivator for one to answer questions. These eureka moments, when you know you found something, is what drives me to solve problems. The Pleasure Of Finding Things Out is a great interview with Richard Feynman that will inspire many on the subject.

In conclusion, curiosity (and scientific research in general) is a cycle that arises when one connects dots when analyzing new answers, which most of the time leads to more unanswered questions.

One makes connections with different sources of data
Questions arises from these new connections
Research is done until a plausible answer (rational and provable for scientists) is found
One uses this new answers to explain some phenomenon, and then the cycle restarts

But not all questions can be answered, because there is an infinite amount of them in all directions. When we accept this fact, curiosity becomes voluntary based. We then have to choose which answers we are able to answer within our limited lifetime.