# Question
Title: What research has modelled the difficulty of mental mathematical calculation?
I posted this also on mathoverflow.

**What research has modelled the difficulty of evaluating a formula mentally (for your average, numerate, person, not a trained mental calculator)?**

For instance, evaluating an arithmetic expression requires in general requires three registers, but some only require two and are considerably easier to deal with. Additions is easier than subtraction which is easier than multiplication which is easier than division. Multiplication by small integer number is easy, as are multiplications and divisions by 2,5,10...

Many rule of thumbs are intuitive, but I'm looking for a more comprehensive work on the topic.

# Answer
There is a huge amount of research on this topic, particularly in developmental psychology.

**Siegler**: As @Joel has noted, Robert S. Siegler provides a great entry point into this literature (see his list of selected publications with PDFs). He has done a lot of research on the strategies that children use to solve mathematical problems. His research includes both empirical and computational modelling approaches. He also has a number of studies that compare performance across features of arithmetic problems. For example, you could look at Siegler and Lemaire (1997) which shows in an adult sample the differences in speed and accuracy for different kinds of multiplication problems (e.g., multiples of 10 or not, single versus double digits). As another example, Siegler and Shrager (1984) show empirical error rates and strategy use in children for all possible combinations of single digit addition.

**Act-R**: There are also a number of publications using the ACT-R framework on mathematical problem solving (see this list from the ACT-R website). Perhaps check out Ritter et al (2007) for a review.

**Defining difficulty**: In general, there are questions about how you would define difficulty. Typical indicators would include task completion time and accuracy. Also, when talking about the difficulty of a mathematical operation, you need to consider the strategy that an individual is using. In particular, there is general shift with practice from using an algorithmic strategy to using a retrieval strategy (for a review, see Delaney et al, 1998). Thus, at first children use strategies like repeated addition to solve multiplication problems whereas with practice, they typically learn to retrieve the answer from memory. The ability to retrieve is broadly related to the number of times the specific problem has been encountered with the correct answer available, along with forgetting effects related to periods where there is no exposure.

### References

* Delaney, P.F., Reder, L.M., Staszewski, J.J. & Ritter, F.E. (1998). The strategy-specific nature of improvement: The power law applies by strategy within task. Psychological Science, 9, 1-7. PDF
* Siegler, R. S., & Lemaire, P. (1997). Older and younger adults' strategy choices in multiplication: Testing predictions of ASCM via the choice/no choice method. Journal of Experimental Psychology: General, 126, 71-92. PDF
* Siegler, R. S., & Shrager, J. (1984). Strategy choices in addition and subtraction: How do children know what to do? In C. Sophian (Ed.), The origins of cognitive skills (pp. 229-293). Hillsdale, NJ: Erlbaum. PDF1 PDF2
* Ritter, S., Anderson, J.R., Koedinger, K.R. & Corbett, A. (2007). Cognitive Tutor: Applied research in mathematics education. Psychonomic bulletin & review, 14, 249-255. PDF
> 3 votes

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Tags: cognitive-psychology, cognitive-modeling, mathematical-ability
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# Question
Title: Do people wake up faster with inconsistent alarm sounds?
Many people have one alarm clock sound that wakes them up every morning.

* Is having this consistent sound the optimal way to wake someone up?
* Or can you startle someone faster by changing to a different sound clip every day?

Assume the alarm clock is going off at the same time every morning.

# Answer
> 18 votes
A general model of processing stimuli suggests that when information does not provide informational value, then we gradually begin to ignore it. Such a model is consistent with the experience of many people in relation to background traffic noise when moving from a quiet to a noisy neighbourhood. I.e., the frequency with which external traffic noise enters into personal awareness gradually decreases over time.

### Habituation to traffic noise while sleeping

It seems that there is quite a lot of research on the effect of traffic noise on quality of sleep and the role of habituation (see this google scholar search on "habituation to noise sleep").

Kawada (1995) provides a review of the effect of traffic noise on sleep. Specifically in relation to habituation the author wrote:

> **Habituation to noise:** Views and opinions on this parameter differ. Thiessen et al. reported habituation to intermittent wakefulness10～12. In their study, subjects were exposed to passing truck noise less than 20 times a night with a peak level of 65 dBA. The probability of a shift to shallower sleep and the amount of deep sleep demonstrated failure of adaptation over 24 successive nights. The probability of awakening decreased by almost one half in two weeks. Griefahn also studied habituation of 36 students to high-density road traffic noise and detected an all-night effect of noise on sleep for 12 consecutive nights13. Deep sleep was prolonged and shallow sleep including intermittent wakefulness became progressively shorter at 37 to 63.5 dBA. Vallet at al. indicate that there is no habituation to noise14. According to experiments on subjects living in a noisy environment for more than four years, young subjects showed less deep sleep and older subjects, less REM sleep under conditions of silence. Both Di Nisi et al. and Ohrstrom reported that there seems to be no habituation to noise exposure15,16. They exposed subjects to randomly distributed noise and it was impossible to predict either the time of exposure or the type of noise presented. Kawada and Suzuki could find no definite habituation to a noisy environment17. Their interval of noise exposure was 15 minutes and there was only one pattern of passing truck noise. Essentially the same noise characteristics are reported by Thiessen, but the findings differed from each other. Based on inter-individual variation in sensitivity to noise, habituation should differ according to the person.

I find this summary a little confusing. The between subject studies are not especially relevant in that habituation should presumably reduce the disruption caused by noise, but not necessarily remove the effect. Thus, it seems like longitudinal evidence would be the most relevant.

### General review of noise on sleep

Muzet (2007) provides a relatively recent review of research on the effects of environmental noise on sleep. With regards to habituation the author wrote:

> \[Autonomic responses, such as heart rate changes and vasoconstrictions in response to noise while sleeping\] have bee found not to habituate over long exposure times compared with clear subjective habituation over successive noise-exposed nights.

### Research on alarm clocks

I found an article by Moorcroft et al (1997) that discussed the role of alarm clocks in peoples awakening process

> The ability to awaken oneself from sleep at a preselected time without external means (such as alarm clocks) was studied using, first, subjective and, second, objective methods. First, in a telephone survey of 269 unselected adults, over one-half said that they never use an alarm clock (or other external means) or always awaken before it. Another 24% said that they sometimes awaken before the alarm. Furthermore, this ability positively correlated with age and was related to consistency in the amount of nightly sleep but not consistency in wake-up time. Second, 15 people who said they regularly self-awaken were objectively tested for this ability in their own beds using actigraphy for three consecutive nights while choosing their own wake-up times. Five awoke within 10 minutes of their target time (mostly before) on each night, five did so on two of the three nights, and of the remaining five, four did so on one night. Choice of target times varied considerably within subjects but more so for those who were more successful. Taken together these results show that many people have the ability to regularly awaken themselves from sleep at a desired time and that such an ability is of practicable utility.

### Does having a consistent alarm clock decrease ability to wake up

I haven't found any specific empirical data on your question.

Habituation processes would suggest that a consistent noise that is deemed to carry a lack of informational content will gradually be more frequently ignored, and thus an inconsistent noise may be more effective in generating attention and perhaps wakefulness. That said, alarm clocks do carry informational content, and people could potentially tune themselves to that noise as the important noise to indicate the time to wake up.

### References

* \[10\] Thiessen, G.J.: Disturbance of sleep by noise, J. Acoust. Soc. Am., 64, 216-222 (1978).
* \[11\] Thiessen, G.J. and Lapointe, A.C.: Effect of intermittent truck noise on percentage of
deep sleep, J. Acoust. Soc. Am., 64, 1078-1080 (1978).
* \[12 Thiessen, G.J. and Lapointe, A.C.: Effect of continuous traffic noise on percentage of
deep sleep, waking and sleep latency, J. Acoust. Soc. Am., 73, 225-229 (1983).
* \[13\] Griefahn, B.: A critical load for nocturnal high-density road traffic noise, Am. J. Ind.
Med., 9, 261-269 (1986).
* \[14\] Vallet, M., Gagneux, J.M., Blanchet, V., Favre, B. and Labiale, G.: Long term sleep
disturbance due to traffic noise, J. Sound
Vib., 90, 173-191 (1983).
* \[15\] Di Nisi, J., Muzet, A., Ehrhart, J. and Libert, J.P.: Comparison of cardiovascular responses to noise during waking and sleeping in
humans, Sleep, 13, 108-120 (1990).
* \[16\] Ohrstrom, E. and Bjorkman, M.: Effects of noise-disturbed sleep: A laboratory study on
habituation and subjective noise sensitivity,
J. Sound Vib., 122, 277-290 (1988).
* \[17\] Kawada, T. and Suzuki, S.: Instantaneous change in sleep stage with noise of a passing
truck, Percept. Motor Skills, 80, 1031-1040
(1995).
* Muzet, A. (2007). Environmental noise, sleep and health. Sleep medicine reviews, 11, 135-142.
* Moorcroft, W.H., Kayser, K.H. & Griggs, A.J. (1997). Subjective and objective confirmation of the ability to self-awaken at a self-predetermined time without using external means. Sleep, 20, 40-45.

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Tags: sleep, hearing, habituation
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# Question
Title: Under what conditions does 60hz video produce visual artifacts?
There are some important thresholds of frame rate in video playback that effect whether or not animation appears fluid. This wikipedia page about Visible Frame Rate suggests that a framerate of 60 hertz doesn't quite provide enough information fast enough to be seen as fluid in some cases:

> However, fast moving objects may require higher frame rates to avoid judder (non-smooth, linear motion) artifacts

When exactly does a higher framerate become necessary? What studies have shown what kinds of motion cause this "judder"?

# Answer
> 9 votes
The Wikipedia article no longer makes reference to the phenomenon that you quote (to my inspection), so I'm not entirely sure if that assertion was edited out as an inaccuracy on someone's part. I did find some information on visual perception and high frequency flicker that might point to some of the significance of the 60 Hz refresh rate of a monitor.

At first I thought the effect you were describing might have something to do with critical flicker fusion frequency. This is the rate under which the blinking of a light is no longer perceived as continuous. For humans this varies from about 37 to 46 Hz (when measured as frequency of stimulus offset and remeasured over the course of the year) and from 43 down to 36 Hz (when measured as a frequency of stimulus onset and remeasured over the course of the year), so if a light blinks at a rate higher than that, it will look like it is continuously on to the average human.<sup>\**</sup> However, since 60Hz is just shy of being a harmonic for the human critical flicker fusion, this seems like there wouldn't be some type of aliasing effect, as there is no 30 Hz component.

What I did find seems to be a plausible reason for some sort of visual entrainment with a 60Hz stimulus, but even the authors of the study (Williams et al 2004) rationalized

> \[If this were the case\] perception should be compromised noticeably when looking at television or computer displays that have 60 Hz (or 50 Hz) frame refresh rates. However, every day more than a billion people watch TV with no obvious distortion in their perception of the color, form, and motion of pictures on the video screen. Thus phase locking in the middle of the gamma \[brain waves\] band \[40 - 100 Hz\] that is irrelevant to the visual scene does not disrupt scene organization or corrupts it so subtly that people do not notice.

That being said, that group performed a very careful study on both humans and non-human primates and found that between 32% and 82% (the percentage increased based on increasing contrast of the stimulus) of "cells" (single-units) studied in primate V1 over all animals were entrained to a 60 Hz refresh rate of the CRT screen. The human Visual Evoked Potentials (using a non-invasive EEG) were all found to be significantly entrained to the 60Hz CRT refresh rate, and were also seen to increase with stimulus contrast. For higher refresh rates of 72 Hz and 100 Hz, the degree of entrainment decreased significantly. So, in both sets of subjects, the 60 Hz flicker induced significant 60 Hz activity in the brain. Activity in the gamma band is normally associated with binding non-local cell assemblies for the purpose of cortical synchronization.

In contrast, though, Bauer et al (2012) found that flickering two "flanker" targets pulsing in phase at 60 Hz while surrounding a central primary target with low contrast did not enhance the ability to see the central target compared to a scenario with two flanker targets firing at 60 Hz out of phase with each other. Building on other work that has been done, they hypothesized that synchrony of neurons in the gamma band (40-100 Hz) would directly help in `"mediating contextual interactions among local stimulus attributes"`. For this study, 60 Hz was chosen as the `"typical frequency for human visual cortex gamma oscillations"` The thought was that the pulsing 60 Hz stimuli would entrain the gamma band oscillations in visual cortex to prime the system for stimulus discrimination. A setup with "in phase" flicker of the flankers with the central target was not found to help in the discrimination of orientation of the primary stimulus either.

So, overall, the 60 Hz seems most likely to have gamma band entrainment effects, but as a caveat, these effects don't seem to significantly hamper our ability to perceive motion on the screen.

---

\**As an aside, I also found a study about the flicker fusion frequency in chickens (which, for some reason, have become a testbed for visual perception tasks). According to an earlier study cited in Railton et al (2010), hens have a critical flicker fusion from 69 Hz to 105 Hz, which is in the typical refresh rate range for CRTs, so the authors of the study found that using thin-film transistor screens was more effective in stimulus discrimination tasks. So, presumably the 60 Hz CRTs would cause a choppy motion from the perspective of the chicken, but I'm not sure this would account for any judder either.

---

## References

1. Bauer, M., Akam, T., Joseph, S., Freeman, E., Driver, J. (2012) Does visual flicker phase at gamma frequency modulate neural signal propagation and stimulus selection? *Journal of Vision 12*(4):1-10. \[DOI\] \[Free PDF\]
2. Luczak, A., Sobolewski, A. (2005) Longitudinal changes in critical flicker fusion frequency: an indicator of human workload. *Ergonomics 48*(15):1770-1792. \[DOI\]
3. Railton, R.C.R., Foster, T.M., Temple, W. (2010). Transfer of stimulus control from a TFT to CRT screen. *Behavioural Processes 85*:111-115. \[DOI\]
4. Williams, P.E., Mechler, F., Gordon, J., Shapley, R., Hawken, M.J. (2004). Entrainment to video displays in primary visual cortex of macaque and humans. *Journal of Neuroscience 24*(38):8278-8288. \[DOI\] \[Free PDF\]

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Tags: cognitive-psychology, perception, vision, sensation, hci
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# Question
Title: What is the test-retest improvement in Block Design test?
**Background:**

My lab is conducting a research on perceptual training. We train participants on different tasks, and assess them pre- and post- training on a large battery of tests. Obviously, people improve in tasks that are very similar to what they trained on, but we are interested in the generalization of training. One of the tests in the pre/post battery is Block Design. We currently do not have a control group that did not train at all. We noticed that all groups improved significantly in Block Design, and we are now wondering if that's only test-retest improvement, but were not able to find data on expected improvement in the literature.

**Question:**

When testing subjects in the Block Design test twice, with the 2 sessions separated by roughly 4 months, what is the expected improvement?

# Answer
**Ronnlund and Nilsson (2006)** studied performance on the WAIS block design test in a large sample of adults both longitudinally and cross-sectionally. The time difference was about 5 years. They wanted to tease out age related changes from practice effects. I believe they estimated the 5-year practice related improvement to be about 0.6 of a T score (i.e., about .06 of a standard deviation).

Benefits of practice presumably decay as a monotonically decreasing function of time between practice and retest. Thus, presumably, any practice effects would be a fair bit greater at two months than they would be at five years.

**Dikmen et al (1999)** performed a study involving 384 adult participants who completed several test including the WAIS Block Design on two occasions separated by between two and twelve months. Specifically see Table 2 that reports time 1 and time 2 results:

```
Time 1 M (SD): 11.3 (3.0)
Time 2 M (SD): 12.0 (3.2)

```

Thus, the standardised increase was $d = 0.7 / 3.0 = 0.23$.

The study also reports in Table 5 practice effects for various test-retest intervals (less than 3 months, 4 to 9 months, and \> 10 months). See Table 5 for more information, but in general greater practice effects were observed for WAIS performance IQ for shorter time periods. Thus, you might expect, given your two month period a slightly larger effect than the overall effect (perhaps $d=.30$ or some such).

### References

* Dikmen, S.S., Heaton, R.K., Grant, I., Temkin, N.R. & others (1999). Test--retest reliability and practice effects of expanded Halstead--Reitan Neuropsychological Test Battery. Journal of the International Neuropsychological Society, 5, 346-356.
* Ronnlund, M. & Nilsson, L.G. (2006). Adult life-span patterns in WAIS-R Block Design performance: Cross-sectional versus longitudinal age gradients and relations to demographic factors. Intelligence, 34, 63-78.
> 6 votes

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Tags: methodology, measurement, experimental-psychology
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# Question
Title: Is there a range in time on which the mind detects correlation between events?
I've been searching for info on this but I'm usually finding unrelated information.

My question is whether there is a time range in which our mind suspects that two events are correlated.

For example: pressing a pedal in the car and hearing a noise (even if it's somewhere else) in the next second makes you suspicious that your action caused that event. If we stretch the time variable (time between those two events), it is less obvious.

Applying this to any other concept, it seems that time is really a factor in terms of correlation detection, but I couldn't find any studies on it.

So, if time is a factor in correlation detection between events, then **which is the effective time range that makes us think two events are correlated?**

# Answer
> 12 votes
I think you are asking about quite a high-level definition of "correlated", and this is obviously going to depend on the particular context or stimulus. That is, knowledge about thunder and lightning allows us to infer that they have a common cause, even though perceptually they can be decoupled (that is, we don't perceive them as occurring together).

However, I can point you to a few things that speak to the perception of correlation in time. This literature concerns the perception of synchrony between two stimuli, such as a flash (vision) and a beep (audition). For visual-auditory pairings, the window of "temporal synchrony" can be quite imprecise: events can be separated by up to 200 ms and still be judged as having occurred at the same time (see Dixon and Spitz, 1980, and Vatakis and Spence, 2006).

However, with multiple events in the environment and depending on the type of stimulus, sensitivity can improve. The above literature as well as my general reply is sourced from this article by Roseboom et al (2011), which may be a good starting point for further reading if this is where you were going with the question.

### References

* Dixon NF, Spitz L (1980) The detection of auditory visual desynchrony. Perception 9: 719–721.
* Roseboom, W., Nishida, S., Fujisaki, W. & Arnold, D.H. (2011). Audio-visual speech timing sensitivity is enhanced in cluttered conditions. PLoS One, 6, e18309.
* Vatakis A, Spence C (2006) Audiovisual synchrony perception for music, speech, and object actions. Brain Research 1111: 134–142.

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Tags: perception, attribution
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# Question
Title: Computational models of early learning in children
> What are currently used biologically plausible computational models/frameworks of early learning in children?

Personally, I have used cascade correlation neural nets to model pronoun acquisition in children, but in hindsight, I consider this framework to be not neurobiologically plausible.

**Are there existing computational frameworks that have been used for early-learning and development in children that have a reasonable biologically justification?** For example: just being a neural net model is not a reasonable justification, but a neural net model witch has local update rules (like Hebbian learning) and models neurons more realistically (instead of just saying they are a sigmoid function without any further biological justification) would be fine. General non-connectionist frameworks with empirical justification are also of interest, even if they don't have a solid reductionist account.

### Notes

I have asked an alternate version of this question on Linguistics.SE that focuses on language acquisition instead of general learning, but considers both children and adults.

# Answer
> 5 votes
Here's something I dug up for language: a Computer Science Thesis from Boulder:

The Sensorimotor Foundations of Phonology: A Computational Model of Early Childhood Articulatory and Phonetic Development (1994)

it discusses what it calls HABLAR (Hierarchical Articulatory Based Language Acquisition by Reinforcement learning).

From the **reductionist/biology side**, developing brains have a much higher population of gap junctions. I would speculate that this would create a much more analog brain, as gap junctions are modeled diffusively, unlike synaptic connections, which can be modeled in a more binary way. I would speculate that the analog driving of the environmental and genetic signals leads to the formation and orgnaization of the synaptic connectivity.

I wonder if one could find a correlation between plasticity and gap junctions. They are found to connect axons laterally in hippocampal cells (a region of brain that remains plastic through adulthood)

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Tags: learning, developmental-psychology, computational-modeling, theoretical-neuroscience
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# Question
Title: Can the Go/No-Go Association Task be faked?
**Go/No-Go Association task**:

> The GNAT (pronounced like the bug) is a flexible technique designed to measure implicit social cognition. Conceptually similar to other implicit measures like the Implicit Association Test (IAT; Greenwald, McGhee, & Schwartz, JPSP, 1998), the GNAT assesses automatic associations between concept (e.g., gender) and attribute (e.g., evaluation) categories. The GNAT has two features that distinguish it from other measures of implicit social cognition. First, the GNAT is designed to be use signal detection statistics in its calculation of automatic associations (d-prime), but can also be adapted to utilize response latency as its operational dependent variable. Second, the GNAT is flexible in the establishing of contextual characteristics for the evaluative situation. For example, the IAT requires an attitude toward one category (insects) be assessed relative to a second category (flowers). With the GNAT, experimenters can vary whether insects are evaluated in the context of a single category (flowers), a superordinate category (animals), a generic category (objects), or with no context at all.

The GNAT is often used with the intention of obtaining an implicit measure of self-esteem, sexism, racism, aggression, and so on. In some cases, test takers may be motivated to score in a particular way on the GNAT (e.g., not implicitly sexist or racist).

### Question

* To what extent can the GNAT be faked?
* If an individual does fake the GNAT, can the faking be detected?

# Answer
> 3 votes
I've never looked at the GNAT before but, even though it's just about as transparent as IAT, the critical thing making it difficult to fake bias is the deadlining. In order to fake one would would have to respond in no-go trials where one would not and that also misrepresented their association. That calculation would be difficult to do in the time window and possibly result in overall very high error rates. I'm not a fan that they just throw out RTs. Furthermore, calculating d' values does not by itself make a task better.

There's a general problem with many of these tasks in that the requested response is directly along the tested dimension. What's implicit about that? Asking you if bad goes with bug does not make for an implicit tests. However, with something like the ALPS (Lebrecht et al 2009) you select an orthogonal dimension for the response (lexical decision in that case). That seems much more like an implicit task and since people tend to be very response focused it makes it much less likely that subjects will pick up on how the test works and attempt to manipulate it. You could also deadline that to make it even less likely that it's cheated.

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Tags: social-psychology, measurement, deception, signal-detection
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# Question
Title: How to computationally model the Wisconsin Card Sorting task?
The Wisconsin Card Sorting task is rather famous but appears to be quite difficult to model computationally.

I work in RL and I am interested in how people learn the optimal strategy. I'm interested in the task because it would allow a number of experimental manipulations. I want to capture the role of *memory* in the optimal strategy. People can keep track of some, but not very much, history of trials when doing the task. (I.e the mathematically optimal strategy seems too computationally heavy.)

* How could I approach modelling the Wisconsin Card Sorting task?
* What other research has modelled the task?

# Answer
Dehaene & Changeux (1991) made a neural-network model:

> The coding units are clusters of neurons organized in layers, or assemblies. A sensonmotor loop enables the network to sort the input cards according to several criteria (color, form, etc.). A higher-level assembly of rule-coding clusters codes for the currently tested rule, which shifts when negative reward is received. Internal testing of the possible rules, analogous to a reasoning process, also occurs, by means of an endogenous autoevaluation loop. When lesioned, the model reproduces the behavior of frontal lobe patients.

Parks et al. (1992) extended the previous neural models of WCST to take into account verbal-fluency.

Amos (2000) built a neural-network model that helps distinguish between the sort of errors made by patients with schizophrenia, Parkinson's disease, and Huntington's disease. He relates the model to neuroanatomy and says:

> The model also made specific, empirically falsifiable predictions that can be used to explore the utility of these putative mechanisms of information processing in the frontal cortex and basal ganglia.

Monchi et al. (2000) followed a similar approach as Amos. Their model suggested different impairments in Parkinson’s disease and schizophrenic patients, and made specific predictions of what would be observed in fMRI scans. They tested this prediction in their paper.

By 2005, the WCST had become a benchmark for more general models. Rougier et al. (2005) made a general model of the prefrontal cortex based on general neurobiological principles as opposed to symbolic approaches. They model learnt from experience and generalized to novel tasks. They tested it on WCST and the Stroop task data for typical and frontally damaged subjects.

Kaplan et al. (2006) use a neural-network approach with two parts: a Hopfield net serves as the working memory and a Hamming block as a hypothesis generator.

Bishara et al. (2010) use a more ACT-R-like (although not actual ACT-R) model with probabilistic loading on symbolic rules. The resulting sequential learning model is used to identify specific process that subjects might be struggling with. It is suppose to help diagnosis in a clinical setting, and they test it on substance dependent individuals.

Rigotti et al. (2010) created a network of randomly connected neurons that could solve the task. The key point was that the random connections induced mixed selectivity, which would solve the task with high probability.
> 10 votes

# Answer
My colleagues have applied the COVIS model of category learning to the WCST. COVIS isn't a model of WCST performance per se, but can account for several known phenomena. See this Google Scholar search: http://scholar.google.com/scholar?hl=en&q=Helie+Paul+ashby&btnG=&as\_sdt=1%2C5&as\_sdtp=
> 2 votes

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Tags: reference-request, cognitive-modeling, computational-modeling
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# Question
Title: How to test effectiveness of a children's museum in improving cognitive function?
For those who have never heard of a Children's Museum before, there is a national association in the US with some information. The basic idea stems from Vygotsky-like paradigms of learning through play.

My first impulse was: write a GUI that presents a series of standard cognitive tests in a fun way, put the software on a computer in a kiosk during the museum events. Finally, compare child performance on the test to the number of visits to children's museum.

Of course, there's some considerations: if somebody takes the test multiple times, they're probably going to get better at it, so this might give a false-positive (rising with the number of visits). So, for instance, only the first test taken by each person would be considered for analysis.

But that is a rather inexperienced shot in the dark. Any other ideas?

# Answer
### General literature on training and educational program evaluation

In general, you would want to read up about program evaluation in general, and educational program evaluation, and training evaluation in particular. With regards to the educational context I found this article online. With regards to training evaluation, you could check out Kraiger et al (1993) or Sackett and Mullen (1993) or any number of other textbook treatments of training evaluation.

### Specific comments on evaluating a "children's museum"

* **What design will you use?**: is it going to be a pre-post design where you compare knowledge before and after exposure to the program? Are you going to have a control group who does not experience the program or experiences an alternative program? How will you allocate participants to conditions? random allocation is better.
* **Decide on the constructs of interest?**: What is the program meant to improve? You speak about quite general learning goals, but training programs are much more likely to have more specific effects. E.g., if you have a program that teaching addition, then students are likely to get better at addition, but their general intelligence is likely to be unchanged. You may also want to think about the time frame that benefits are meant to persist after exposure to the program. You can also look at Kirkpatrick's framework of training evaluation which talks about different kinds of outcome variables.
* **What will measure your constructs of interest?**: Are you going to use existing measures or develop your own measures? If the content is highly specific to your program, then you will probably need to develop your own test items.
* **Determine your sample**: How are you going to recruit your sample? How many participants will you need to ensure reasonable statistical power?
* **When and how will measures be administered?** I think you would want to do this in a controlled setting. A kiosk would probably be problematic from a measurement perspective.

### Rough starting point

Of course there are a whole range of issues related to program evaluation, and dealing with children introduces many additional issues. The following might provide a rough starting point:

* two groups: control and intervention; about 100 participants per group
* three time points: before intervention, immediately after intervention, a few months after intervention
* Use some general measures of ability related to the program as well as some highly specific measures that tie in closely to program content.
* Also measure other factors like child and perhaps parent reactions to the program including both quantitative and qualitative evaluations.
* Perhaps link in with some surrounding schools or day care facilities to recruit participants or use some form of waiting list system for admission to the program. Administer tests in a controlled environment (e.g., in a supervised room).

### References

* Kraiger, K., Ford, J.K. & Salas, E. (1993). Application of cognitive, skill-based, and affective theories of learning outcomes to new methods of training evaluation.. Journal of applied Psychology, 78, 311. PDF
* Sackett, P.R. & Mullen, E.J. (1993). Beyond formal experimental design: Towards an expanded view of the training evaluation process. Personnel Psychology, 46, 613-627. PDF
> 4 votes

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Tags: learning, developmental-psychology, test, educational-psychology, perceptual-learning
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# Question
Title: What are the key examples of the use of computational methods in the study of biological neural networks?
In an upcoming postdoc, I'm going to be looking through biological neural network data in the hopes of finding some interesting "patterns". I'm coming at this field from a mathematics/computer science point of view, and am quite new to the biological side of things. I'm hoping that by looking at some examples in which computational methods were successfully used in understanding biological neural networks, it might help me understand more about what I should be looking for, and what approaches are likely to be successful.

> **Question**: What are some key examples in which computational methods were used on biological neural networks to gain important insights into these networks?

# Answer
I'd like to add to Chuck's excellent answer; the computational approach is very well-represented in neuroscience, and actually involves a large number of very heterogeneous methods. Thus, a very different set of neuroscientists and examples have sprung to mind for me.

To my mind, the best single example of the utility of a computational approach to interpreting neural data is the reward prediction error hypothesis of dopamine function. Early investigations in machine learning led to the development of the temporal difference reinforcement learning algorithm. Subsequently it was noticed, by Wolfram Schulz, that the pattern of firing in dopaminergic cells appeared to closely correspond to what would be expected of a temporal difference error signal - the very core of this form of reinforcement learning. Subsequently, similar reinforcement learning algorithms (e.g., Q-learning) have been applied to a variety of neural data - albeit at the much coarser scale of fMRI - and provided a variety of evidence that is strongly supportive of this hypothesis. This work has been absolutely crucial to progress in the last 10-15 years in cognitive and systems neuroscience.

The second example that springs to mind also pertains to dopamine; in this case, the utility of the computational approach was in understanding the pattern of effects produced by release of dopamine, rather than in characterizing the pattern of dopamine release itself. At the cellular level Jeremy Seaman's work is a great example of this approach; he has used Fisher discriminant analysis and other multivariate techniques to better characterize multi-unit activity recorded in prefrontal cortex, under various dopamine conditions. Ultimately his work has been the primary computational approach contributing to what is now the modal understanding of dopamine's effect in the prefrontal cortex, which is to enhance signal to noise ratio.

A third example has to do with the application of graph theory to neural networks, and in particular our understanding of small-world connected graphs. The implication of this work for neuroscience was not lost on the mathematicians that originally pursued this line of work, but its actual utility for neuroscience has been most famously demonstrated by Olaf Sporns in understanding what is coming to be called the "connectome" - that is, the graph of structurally- and functionally-connected neural systems. Although this is still an active line of research, small-world connectivity appears to be a ubiquitous feature of cortex.

I would be remiss not to mention the work of a large group of researchers trained in the "parallel distributed processing" or connectionism tradition, including Matt Botvinick, Jon Cohen, Michael Frank, Ken Norman, Yuko Munakata, Randy O'Reilly. There are too many excellent examples from their work to name, but all of these researchers have used behavioral and neural data to build neural network models of cortical and subcortical processing, at varying levels of biological detail; validated these models in terms of their fit to existing behavioral and neural data; and used these models to derive predictions that have subsequently been tested using a variety of approaches. The following is a woefully incomplete, but at least representative, list of the progress made by these researchers: the discovery of parallels between the dimensionality-reduction or "abstraction" techniques that can be useful in reinforcement learning to cortical processing (in the case of Matt Botvinick); the discovery of parallels between the exploration/exploitation dilemma in reinforcement learning and the function of the locus coereleus/norepinephrine system (in the case of Jon Cohen); the understanding of fine-grained functional consequences of differences in dopamine receptor subtypes, as well as prefrontal/striatal interactions (in the case of Michael Frank), the discovery of the large-scale consequences of cellular-level long-term depression and potentiation phenomena for hemodynamic patterns in memory tasks (in the case of Ken Norman), the discovery of the role of prefrontal inhibitory neurotransmission in tasks requiring "selection" of information under competition (in the case of Yuko Munakata), and the discovery of the computational underpinnings of the tri-partite division of labor between hippocampus, posterior cortex, and prefrontal cortex (in the case of Randy O'Reilly). Jay McClelland, David Rumelhart, David Seidenberg, Geoff Hinton, and many others laid the groundwork for much of this progress, although their contact with detailed neural phenomena was more limited than that made by their trainees (and their trainees' trainees), above.

I would conclude by seconding Chuck's suggestion to do a PubMed search. Your question is too broad for a comprehensive answer conveyed in anything shorter than a book!
> 12 votes

# Answer
There are many neuroscientists who use the techniques of advanced mathematics and statistics to analyze actual neural data for patterns.

George Gerstein, who is now retired, has been a pioneer in applying "particle" methods in analyzing neuronal interactions. The originator of the Gravity transform, he used this tool to untangle some of the stochastic processes that were underlying the firing patterns. He also brought into widespread use tools like the joint peristimulus time histogram, which allow an "at a glance" view of co-firings.

Emery Brown is both an anesthesiologist and academic statistician who has done a lot of modeling with actual hippocampal place cell data in a Bayesian framework, as well as modeling firing patterns with point processes. He, along with some other groups, have successfully used tools like Granger Causality to reveal connectivity among cells and subcircuits.

G. Bard Ermentrout is a bit more theoretical, as he is a mathematician, but has done a lot with determining the phase space relationships and coupling in neuronal firing patterns, and has often tested his models with neural data. He has "written the book" on the subject.

There are hundreds more examples, but these are the first three that sprang to mind. Neuroscientists are eager and willing to collaborate with mathematicians, statisticians, and others of the theoretical ilk (as you're seeing), so doing a quick Pubmed search on areas that are of particular interest to you is probably the best way to seek out these subfields.
> 11 votes

# Answer
The use of neural-networks in the cognitive sciences has been around since Turing. However, many of the networks common in connectionism suffer from a lack of biological plausibility. Of these abstract ones, even the ones that try to capture some properties of biological neural networks only do some metaphorically. See for instance the limitations of cascade correlation as a metaphor for neurogenesis. However, these abstract networks are still used because they provide a great bridge between theory in neuroscience and psychology. The networks are abstract and powerful enough to deal with questions in psychology (say learning or developmental-psychology) but still try to ground themselves in some way (at least by analogy) in biological network. I will give two examples from this abstract working down towards biology point of view.

Most of the early approaches to neural nets, represented activation as real-valued outputs that were multiplied by the weights of interneuron connections. This approach is being replaced by more reasonable spiking neuron models that incorporate a more realistic coding medium (rate of action potentials) while still maintaining a relatively abstract level that is usable in psychology and machine learning applications. However, these models still tend to be too abstract to realistically model specific organisms.

Chris Eliasmith and his students have pushed a little further in the gap between abstract psychology-useful models and concrete biologically-useful models by proposing the neural engineering framework. This computational model allows users to run a range of simulations from close-to-biology studies like translational vestibular ocular reflex in monkeys and recognition of song by zebra finch to psychology-studies like parametric working memory and other kinds of cognitive models.

Thus these approaches allow you to understand certain properties of biological neural networks by looking at the essential features of abstract models

Of course, you can push things closer to biology, and @ChuckSherrington's answer gives some great examples of this.
> 8 votes

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Tags: neuroscience, computational-modeling, neural-network, theoretical-neuroscience
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# Question
Title: Are there shapes defined by 3 (or more) generative parameters whose mapping to psychological similarity space is known?
I am trying to generate 4 shapes that are equidistant in psychological similarity space - meaning that they are all equally discriminable from one another - which differ in 3 parameters, such that those parameters have a known mapping between objective and psychological space.

A simple example may help. We might define an object in terms of its width, height, and depth. The four objects A, B, C and D would have values as follows:

```
    height   width    depth

A.    2        2        1

B.    1        1        1

C.    2        1        2

D.    1        2        2

```

These points are equidistant in 3d euclidean space (they are actually the vertices of a tetrahedron). However, an increment of 1 in height may not be perceived psychologically as distinct as an increment of 1 in depth (in principle). More problematically, going from 1 to 1.5 may not be psychologically the same as going from 1.5 to 2 on any dimension, meaning that while these values are continuous, they are not linear in psychological space. In other words, objects equidistant in the metric of the parameters I'm using to generate them may not actually be equidistant in the eye/mind of an observer.

This is particularly true for this example, as point B is clearly more visually distinct from the others - it's the only cube!

I am therefore looking for 3 shape parameters where the mapping from objective space to psychological space is known, and in which there is not a loss of dimensionality in this mapping to below 3 dimensions in psychological similarity space.

I suspect this is not known, but I would like to avoid reinventing the wheel (not to mention running the complex pilot experiment this would require - it's not even my question of primary interest!)

# Answer
> 6 votes
Consider the **colour visual system**. Take 3 monochromatic (in the physics sense) light sources of wavelength $420 \\; nm$, $534 \\; nm$, and $564 \\; nm$; i.e. the peaks of spectral sensitivity for cones. Your 3 physical parameters are then 3 knobs $b$, $g$, $r$ that control the intensity of each light source as they shine on the same white surface. If you want more physical parameters, you can just add more knobs for other monochromatic lightsources, however 3 is sufficient. Colour perception is extremely well studied, so this comes as close as I can think of to a known mapping between between objective and psychological space. Unfortunately, you will run into some culture and language specific issues for judging the similarity of perceived colours.

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Tags: cognitive-psychology, perception, cognitive-modeling, vision, perceptual-learning
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# Question
Title: Is it possible for certain people to perceive colors differently?
What if someone perceives a color as 'red' when it is actually 'green'?

Since different people have preferences for different colors, and colors are perhaps constructed in the mind, is it possible that the entire space of colors can be experienced quite differently for some people?

# Answer
> 13 votes
Yes, this scenario is possible, occurring with certain cases of brain lesions in specific areas of the visual cortex, the fusiform, lingual and posterior parahippocampal gyri. These areas are analogous to what is referred to in primates as V4, or the 4th visual cortex, and are known to be involved (at least partly) in the perception of color (though see this commentary).

<sub> Courtesy wikipedia </sub>

In this study, subjects with brain lesions were asked to identify colors in a blue ambient light (meant to mimic the outdoors) and under a reddish light (meant to mimic indoor lighting).

> ... the three patients...with abnormal matches on the blue, green and red chips made different matches than control subjects for pink, violet, turquoise and green targets... Their matches for these chips were shifted towards orange-red for the pink and violet targets and towards green for the turqoise target. One patient displayed a shift toward turquois\[e\] for the green target.

So, the level at which this "signal" is getting crossed can only be inferred from the level of the lesion, but presumably, the transduction of color by the cones and the processing of the colors in the P and K cells of the Lateral Geniculate is all still intact.

> Clarke, S., Walsh, V.,Schoppig, A.,Assal, G., Cowey, A. (1998) Colour constancy impairments in patients with lesions of the prestriate cortex. *Exp Brain Res 123*:154-158.

# Answer
> 13 votes
As @Gray mentioned, the philosophical problem you are interested in is known as the inverted spectrum. Unfortunately, @Gray's claim about no empirical difference is not exactly true. As @ChuckSherrington pointed out, we can have differences in color perception due to brain lesions, but this is cheating in way. We don't have to go this far, we already have differences in color perception between neurotypical people based on their culture/language. More dramatically, we can observe this difference within a single individual!

As I explained in a previous answer: physics does not have colour, it just has a continuous spectrum of wavelengths. Even when you look at the sensitivity of the 3 types of cones in the retina it is not discrete, but continuous. The categories of colours (i.e. "that's red", "that's blue") are produced by perception and these discrete-ish categories form the basis of colour qualia. Scientists can study these categories by asking participants if various stimuli feel like the same colour. The arbitrary boundaries of the categories people draw between colours is language dependent (Regier & Kay, 2009)! In other words, we have support for the Whorf hypothesis: language effects your subjective conscious experience.

But the buck doesn't stop there. Gilbert et al. (2006) showed that the Whorf hypothesis is supported in the right visual field but not the left. In other words, when I present colours in one part of your visual field, you experience them one way and when I present them to the other then you experience them in a fundamentally different way.

Thus **different colours can be experienced differently by different neurotypical people**, and in fact they can be **experienced differently by the same person** based on which visual field the stimuli is presented in. Further, this difference is empirically measurable! Of course this doesn't resolve the inverted spectrum problem completely, but that is to be expected since philosophy always has a way to run away from science.

# Answer
> 4 votes
I would point you towards the debate on qualia in cognitive science. It has been argued by some philosophers such as David Chalmers that there are internal qualitative states separate from their physical realization. http://en.wikipedia.org/wiki/Inverted\_spectrum

With the exception of color-blindness and other differences in visual circuitry such as Tetrachromacy there would be no empirical difference in the response of such a person with differences in their qualitative experience of color. So its an interesting question whether such differences in qualia exist or are even meaningful to talk about.

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Tags: vision, sensation, philosophy-of-mind, color
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# Question
Title: Medium-term effects of polyphasic sleep on performance
Typical sleep patterns of one big block of 6 to 9 hours with no naps is usually referred to as monophasic sleep. A second natural sleep pattern is biphasic sleep which breaks up your sleep into two chunks (Wehr, 1992; Ekirch, 2001). My question concerns polyphasic sleep which partitions your sleep in 3 or more periods during the day.

From personal experience (and anecdotal evidence; this is a popular blogging topic), I know that the first one to two weeks of trying to keep a difficult polyphasic sleep schedule (say uberman that divides your day into 6 evenly spaced half-hour naps) produces very low performance. At first you are unable to fall asleep and you need your alarm clock to wake up and you feel groggy, agitated and slow. However, after the first week, a lot of these negative effects seem to disappear as you grow accustomed to the schedule. You start to get very vivid dreams during your naps (and I started to wake without the need for alarm clock) suggesting REM sleep. However, I have never subjected myself to proper performance tests while attempting polyphasic sleep.

**What are the medium term (more than 2 weeks, less than a year) effects of polyphasic sleep on performance of tasks like working memory, reading speed and comprehension, and IQ tests?**

Unfortunately, most sleep studies are less than two weeks in duration and report the obvious negative effects; except on working-memory which benefits from naps. Alternatively, they are military studies that only track vigilance (not having micro-sleeps)(Porcu et al., 1998; Rhodes & Gil, 2003) , or have physical measures of no interest to me (Stampi, 1989).

# Answer
<sup>**Disclaimer**: As you have noted yourself, there aren't very many scientific researches on the topic. The only main points that I can derive are generally of blogs or sketchy speculations. As such, you are supposed to take this answer with a grain of salt.</sup>

Interesting Thing of the Day notes that polyphasic sleep may make the person awake and alert but have adverse effects on the creativity and mental agility.

> ...it may be that although one can indeed be awake and alert for 22 hours per day, creativity and mental agility suffer as a result.

Supermemo has the following to say about Polyphasic sleep:

> Yet you will definitely **not** want to sleep polyphasically if:
>
> * you want to maximize your creative output
> * you want to maximize your peak alertness, your average alertness, or minimize the impact of your worst alertness levels
> * you want to maximize the health effects of sleep, etc.

While both the sources are not scientific findings, it does send a signal that polyphasic sleep cycles would have a negative impact on IQ tests and general activities like reading because your overall alertness is down because of sleep deprivation. Poor mental agility would have result in a lower working memory as well.
> 8 votes

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Tags: experimental-psychology, performance, sleep, working-memory, iq
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# Question
Title: How to change the brain in order to change how one habitually thinks and feels?
In this snippet from "You Are Not Your Brain: The 4-Step Solution for Changing Bad Habits, Ending Unhealthy Thinking, and Taking Control of Your Life" by Jeffrey Schwartz

Schwartz states that refocusing attention can actually change brain structure so that habitual ways of the brain are physically broken and other new healthy behaviors become habitual with new connections in the brain.

Are their any other studies along these lines that mention how to change how one thinks and feels habitually?

# Answer
There's over 100 years of learning research and theorization now that pretty well establishes that yes, if your behaviour changes then your brain changes (and vice versa). When you learned to tie your shoes your brain changed. It quickly became a habit and you don't even think of it... can't even do it if you do. When you learned to speak your brain changed. When you had a child of your own and spent 6 weeks without regular sleep your brain changed. It's hard to give you a specific reference for any of that. The brain is what guides your behaviour. If your behaviour is changing then your brain is changing. Your brain changing is neither magical or surprising, that's how you learn.

That said, I've never seen the "habit" centre.

If you really want a reference start with this.

\[Aside: It's kind of absurd that he talks about how you are not your brain but now you're going to change your brain to make a new you.\]
> 9 votes

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Tags: reference-request
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# Question
Title: Do men and women differ in their desire to have children?
I was reading the comments of the following article on paternal health and birth defects. Someone made the following comment.

> The other thing is that mens interest in being a father is nowhere near a high priority as women's is to be a mother.

While this seemed like uninformed opinion, it seemed to raise an interesting question.

* **Is there any scientific empirical evidence to suggest that males and females differ in their desire to have children?**

# Answer
### Caveats

Even when the degree of men's and women's desires to have children are forced by study parameters into yes/no pigeonholes, there are very few studies, and the results are arguably inconclusive. Also, men's and women's rates of desire to have children are continuously shifting, and thus the answer may change over time. Finally, the studies have been limited to the United States and/or the United Kingdom.

### Findings

### Conclusion?

A tentative conclusion could be that men are more decisive, outnumbering women in both categories -- wanting to have and wanting NOT to have children. But, more research is required to reliably answer your question, and by then the answer may have changed.

### References

> * Gore, D.L. (2002) I Don’t Want Any Children... Ever: Gender Differences in Voluntary Childlessness in the US, 2002 \[pdf\]
> * McAllister, F. and Clarke, L. (1998) Choosing Childlessness. London: Family Policy StudiesCentre.
> 11 votes

# Answer
I would like to point out impact of having kids. In typical case, kids have much greater impact on many levels of her life, than on his. I have seen more research on this topic, but now I found just a few examples

> Anne-Marie Nicot (2009) Impact of parenthood on careers of young men and women read - not original research
>
> Does having children create happiness? read - interesting references included

Also, as has been mentioned in one of papers above:

> "Motherhood is seen as a sign of achievement and femininity, while a man’s accomplishments are viewed through his income and career." (Gore, 2002)

Therefore, I would say that asking a man whether he want or doesn't want to have kids is a completely different question than asking a woman the same thing.

Having this on mind, you can see, how to interpret results in answer of John Pick. Asking men, they have less trouble to reach a decision and hold on to it. It is a serious question, but not quite as much serious, as the same question for women is.

You do not ask a man, if he wants to be pregnant, if he wants to give birth, if he wants to leave his career for some time and then return as woman with kids (means someone who is expected to be worse work candidate because of the household and kids). You also do not ask him, if he wants to have an opportunity to achieve something in the field typical for his gender.

Imagine asking someone, if she wants to have children. And then imagine asking someone else, if he wants his partner to have children. It is not the same question and comparing answers only emphasises this fact.
> 7 votes

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Tags: sex-differences, parenting
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# Question
Title: What is a reliable physiological measure  (e.g., serotonin levels)  of positive affect?
* **Is there a reliable physiological measure or correlate to positive affect?**
* **What does research say on this?**

I thought that serotonin levels are correlated with self-reported happiness levels, but, after a google scholar search I am not so sure. I tried google scholar and couldn't find any papers reviewing/summarizing multiple experiments. I only found a whole lot of papers with vague sounding titles than what i am looking for.

EDIT 1: Replaced happiness by positive affect. As Geek on Acid pointed out happiness is too general.

# Answer
> 10 votes
First - you might want to redefine you search. Are you looking for **happiness** or rather **positive affect**? **Happiness** is fairly ambigious term, and it's much more associated with positive psychology studies on well-being. If you are interested in more global definition of happiness, check the work of Mihaly Csikszentmihalyi.

On the other hand, there is a large number of studies on physiological measurements of **positive affect**.

One such physiological measurement is **Electromyography (EMG)** \- recording the electrical activity produced by skeletal muscles. EMG will detect very brief smiles or higher activity in cheek muscles (zygomaticus major) which are correlated with positive affect. There is quite classic (but very quoted) paper on that:

> Cacioppo JT, Petty RE, Losch ME, Kim HS. (1986) Electromyographic Activity Over Facial Muscle Regions Can Differentiate the Valence and Intensity of Affective Reactions. J Pers Soc Psychol., 50(2):260-8. download

Another simple physiological assesment is **heart rate** measured by the interbeat interval (IBI). For example, study by Brosschot & Thayer (2003) shows that heart rate response is longer after negative emotions than after positive emotions.

> Brosschot JF, Thayer JF. (2003) Heart rate response is longer after negative emotions than after positive emotions. Int J Psychophysiol., 50(3):181-7.

In fact, the full spectrum of somatic measurements have been used along heart rate including **pulse transmission time** to the finger, **skin conductance level** or **pupil dilation** (Partala, 2003). All those are a bit less reliable methods and usually they detect arousal rather then indicate physiological differences between positive and negative affect.

> Partala T.; Surakka V. (2003) Pupil size variation as an indication of affective processing. International Journal of Human-Computer Studies, 59(1):185-198. download

Finally, I would advise browsing literature on measurements of **negative affect**. You are likely to find some interesting methods there, like in this paper on the psychophysiology of crying (Gross et al., 1994).

> Gross JJ, Frederickson BL, Levenson RW. (1994) The psychophysiology of crying. Psychophysiology, 31(5):460-8. download

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Tags: neuroscience, emotion, well-being
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# Question
Title: Are there known cases where people can write upside down?
From the time I was able to write I have been writing upside down, as in literally turning the page 180 degrees and writing. The funny thing is, I can't write the right way up! I am left handed which would probably make this more clear but to this day I find it really weird! I can easily read upside-down mainly because I've always had to write upside down!

I've never been trained to write in this way nor do I know anyone who can write like me! I've always been comfortable writing this way. I know nothing is wrong with me, but I am curious to know if there are other cases like me or maybe even explainations?

# Answer
> 5 votes
Leonardo da Vinci wrote both upside down, and in a mirror image. He did the latter partly to make it harder for others to read his journals and copy his ideas (he was doing his research in a time when it was forbidden by the church), but also to avoid smudging his writing. He was also left-handed.

Here is someone who also writes upside down and backwards. And here is a case of a mother asking if she should be concerned because her 2 1/2 year old daughter writes upside down.

# Answer
> 4 votes
This phenomena is much more common than most people realize. I have been working with several elementary students over the last three years who could not read and write conventionally, but can do so easily when the book/paper is upside down.

My wife and I also recently conducted an interview with a 74 year old retired reading teacher who discloses that she, too, was an inverted reader and writer before she entered 1st grade. Upon entering 1st grade she was discouraged from doing what came naturally, and unsuccessfully labored to read and write conventionally throughout her early academic career.

To view this interview and many others of children reading and writing inverted, simply GOOGLE PIreading.com

As requested, here's a link to the interview: http://www.dropshots.com/teacherman9000#date/2012-02-23/04:49:12

# Answer
> 3 votes
When lefties write left to right they face three difficulties:

1. They risk smudging what they have already written
2. The natural way to hold a pen means it is likely to dig in to the paper, rather than be drawn across it.
3. They tend to slope the letters backwards. I don't really understand why, but righties can demonstrate this for themselves by writing lefty

Rotating the paper alleviates these problems to some extent. I've noticed many lefties do it, though not to the extreme you describe.

# Answer
> 2 votes
We have been studying behavioral and neural mechanisms of upside-down writing and reading in a case of a young left-handed women who writes and draws upside-down only. Apart from some interesting spatial processing results (superior in some tasks) we have no explanation so far. We did discover, however, that this phenomenon is much more common than hitherto believed. Sally, please let me know if you would like to hear more about the study. We would, of course, benefit from hearing more about your writing.

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Tags: writing
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# Question
Title: Can psychosomatic reactions be completely unconcious?
I had always considered that psychosomatic reactions, such as Psychogenic pain, while "real" to the person experiencing them, would be a concious reaction at some level. That is to say, if the person told themselves "this isn't real" - they would be able to tell that the reaction was "in their head".

However, after some recent research on Couvade Syndrome I became curious if a person could have completely unconscious physchosomatic reactions that they could not suppress with "will". Assume in this case we're talking about an otherwise mentally healthy individual who isn't hearing voices or anything like that.

# Answer
Good question and this is very big topic mate. Short answer is - every psychosomatic disorder is unconscious in the sense that it's coming from psychological tension but reflects itself in some unpleasant somatic/bodily reaction (e.g. headache, lower back pain, high blood pressure). In general, even if you are conscious of the source of psychosomatic reaction (e.g. stressful job causing evening headaches) you can't really talk yourself out of it. But you still can make some short term changes (pop a pill) or long term changes that (quit a job, meditate) to reduce the psychosomatic effects (Grossman et al., 2004).

> Grossman, P., Niemann, L., Schmidt, S., Walach, H. (2004) Mindfulness-based stress reduction and health benefits - A meta-analysis. JOURNAL OF PSYCHOSOMATIC RESEARCH, 57 (1): 35-43

But it's probably not that simple. While we can say that psychosomatic disorders are by default unconscious, we need to consider wider range of factors that causes them and ask more questions.

One such question is **why people get psychosomatic disorders**? Stress is the best, most popular, most studied, most quoted, and most mysterious, simple, single answer to this question. Ulcers, asthma, chronic fatigue syndrome, rheumatoid arthritis - you name it. In general terms, increase in cortisol due to stress punches holes in your body, although the lack of cortisol has been argued to have impact too (Heim et al. 2000).

> Heim, C., Ehlert, U., Hellhammer, DH., (2000) The potential role of hypocortisolism in the pathophysiology of stress-related bodily disorders. PSYCHONEUROENDOCRINOLOGY, 25 (1): 1-35.

But you see, the longer I think about it, the more complicated it becomes. So I stop here.
> 6 votes

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Tags: cognitive-psychology, unconscious
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# Question
Title: How to measure well-being without using an extensive questionnaire?
I'm trying to create an iPhone app for music therapy (or other kinds of experimental therapy). Such app would help a music therapist keep track of sessions and evaluate progress. One of the issues that I'm facing is evaluating the effects of therapy - I would like the user to rate their "well being" before the session and immediately following the session using iPhone screen.

I want the rating process to be a one tap operation - I'm thinking of producing an X-Y like graph with two axis and letting the user tap on the chart to rate their well being.

While I can create my own graph like that (for example thought(positive/negative)/action(no desire to act/desire to act)). I'm wondering:

**Is there a more scientifically accepted or validated scale of well-being that does not involve extensive questionnaires?**

If there are no such axis, can you suggest which other metrics I may use in an app like that.

# Answer
In general, having multiple items will increase your reliability of measurement. A common measure of what the literature calls "subjective well-being" is a combination of the following scales.

* The PANAS: A measure of positive and negative affectivity. A 20 item measure of positive and negative affect (see Watson et al, 1988).
* Diener's Life Satisfaction Scale. Five short items measuring life satisfaction.

I.e., well-being is measured as a combination of high positive affect, low negative affect, and high life satisfaction. Of course, there are many other measures of subjective well-being (for a review, see Kahneman and Krueger, 2006).

### When to use single item and when to use multiple item

In general there are trade-offs in research. More items brings greater reliability but it also takes more time, which can potentially reduce participation or lead to other costs.

A single item measure of well-being might be appropriate when:

* measuring the construct reliably is not that important
* You are concerned with population level estimates and you have large sample sizes per group
* You are doing experience sampling research where you are getting tens or hundreds of observations of well-being at different time points, and thus, participant fatigue is a major issue.

In your case, you are conducting a pre-post study to assess the effect of an intervention. In such cases, it would really be worth administering a reliable multi-item measure of well-being. For example, to complete the PANAS plus Diener Life Satisfaction combination above, might only take a couple of minutes. For the sake of getting reliable measurement, that seems like a valuable use of two minutes.

### Affective grids

That said, if you still wish to explore single item measures, check out this previous answer on where Gaël Laurans mentions Russel et al 1989 and Larsen et al 2009 as useful sources:

### References

* Watson, D., Clark, L. A., & Tellegen, A. (1988). Development and validation of brief measures of positive and negative affect: The PANAS scales. Journal of Personality and Social Psychology, 54(6), 1063-1070.
* Kahneman, D. & Krueger, A.B. (2006). Developments in the measurement of subjective well-being. The journal of economic perspectives, 20, 3-24. PDF
* Russell, J.A., Weiss, A., & Mendelsohn, G.A. (1989). Affect Grid: A Single-Item Scale of Pleasure and Arousal. Journal of Personality and Social Psychology, 57 (3), 493-502.
* Larsen, J.T., Norris, C.J., McGraw, A.P., Hawkley, L.C., & Cacioppo, J.T. (2009). The evaluative space grid: A single-item measure of positivity and negativity. Cognition and Emotion, 23 (3), 453-480.

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> 6 votes

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Tags: measurement, well-being
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# Question
Title: How can prolonged stress lead to a sustained reduction in cognitive functioning?
**Background:** Ten years ago or so I went through a traumatic period which resulted in a lot of stress and anxiety. I initially assumed there was some depression but cognition and short term memory was gradually affected such that I had serious difficulty understanding new concepts at night class. At one stage I was practically "cut off" from emotions. I understand that this could be partly due to something happening on the hormonal or biological level.

### Questions

* What does research show about the causal effects of stress on cognitive functioning?
* How is the brain affected by stress? (e.g., chemical/physical, or perhaps a "softer" level).
* What could be done to minimise the negative effects of stress on cognitive functioning?

# Answer
This is only one possible pathway. There are many potential ones. Further the fact that this is possible does not mean that it is the case always.

Stress activates the hypothalamic-pituitary-adrenal (HPA) axis. For example, a meta-analysis by Dickerson et al. (2004) demonstrated that an acute laboratory based stressor reliably increased cortisol levels, a hormone downstream of the HPA. That stress results in activation of the HPA is also well-demonstrated in animal models, where both physical (e.g., restraint or shock) and social stress (e.g., Engelman, 2004).

When stress occurs, various systems (e.g., amygdala implicated in threat detection) can lead to activation in the hypothalamus, where the paraventricular nucleus (of the hypothalamus) secretes corticotropin-releasing hormone (CRH). The CRH acts on the pituitary gland resulting in a release of adrenocorticotropic hormone (ACTH). ACTH is released into the blood, which allows it to reach the adrenal glands, specifically the adrenal cortex. This stimulates the adrenal cortex to produce and release glucocorticoids (GCs) into the blood (in humans primarily cortisol, in animals corticosterone). GCs in turn have broad ranging influences on the body. For example, they seem to play role in immune regulation and function (although whether they are anti-inflammatory or pro-inflammatory seems to depend on quantity and time (there was a lively debate about this at a Psychoneuroimmunology conference. For utterly inadequate notes on some of the presentation see here).

GCs also act in a negative feedback loop to shut off the HPA axis. Finally, relevant for cognitive functioning, specifically memory, GCs can regulate the hippocampus. This is believed to be adaptive in the short term, but when the hippocampus is chronically exposed to elevated levels of GCs, it can endanger cell function (for a review of GCs and the hippocampus, see Joels, 2001).

For example, using a longitudinal design, Huang and colleagues (2009) demonstrated that in people with Alzheimer's Disease, basal plasma cortisol (cortisol levels in the blood, other major ways to measure cortisol are via saliva or urine) was predictive of a decline in cognitive function as well as atrophy in the hippocampus (specifically, the temporal horn).

Somewhere I have a slightly longer reference list on stress and aging, with an emphasis on stress effects in cognitive and physical function over time. I do not have an answer for your final point, what can be done to minimize the effects. The only clear suggestion would be to minimize stress. I know there are some studies showing protective effects of physical activity for depression, physical function (that one's a no-brainer), and cognitive function. One can speculate that if chronically elevated GCs released from the adrenal cortex are the cause, that administering an ACTH antagonist or the like may help, but to date, I know of no studies trying to block the effects of stress (in rodent models of cancer, stress effects on tumor progression and metastasis have been effectively blocked using beta blockers, but there the primary stress pathway was believed to be sympathetic nervous system activation rather than HPA).
> 8 votes

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Tags: abnormal-psychology, psychiatry, neurology, stress
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# Question
Title: Are some methods of teaching reading "bad"?
I have a young daughter who I am teaching to read, and I was given a "Your Baby Can Read" DVD set by a friend. When discussing it with friends, several of my teacher friends frowned upon the use of "memorization" to teach reading, and implied it would have negative long term effects. Is there data to support this claim? Since I expect there is a lot of research in this area, are some methods of teaching reading considered "bad"?

For reference, the "Your Baby Can Read" series proposes that babies even can "read" even before they can talk by watching videos and looking at books which show words and then show a picture or short video that explains the word. This is intended to make the connection between the word and what it represents, and ideally guide the child in a reaction to indicate they know what it means. There is no mention whatsoever of spelling, or phonetic sounds - it is all word/picture or word/video associations one after another.

# Answer
In general, parental involvement/engagement has lots of positive social, emotional, cognitive, and academic effects for a child's development. Some evidence suggests that the positive effects of relatively general factors like improved parent-child relationship, increasing motivation and (positive) expectations, etc., are stronger than the specific benefits of learning particular educational material. Based on this, I would say that if you and your daughter enjoy doing these learning to read activities, then they will have positive effects because they will teach your daughter that reading is important and that her parents care about her and her intellectual/academic development, whether or not your daughter specifically learns to read from this DVD.

On the specific subject of reading, it is important to keep in mind that the vast majority of children will learn to read regardless of the particular method of instruction. Phonics-based methods (which emphasize letter-sound correspondences) are generally thought to be more effective than whole-word methods, especially for children at risk for reading disability/dyslexia. However, even the most die-hard phonics supporters acknowledge that phonics needs to be embedded within a comprehensive reading instruction program that makes reading fun and meaningful. In other words, phonics is the best method, but any fun reading activities that you do at home to get her interested in books will have positive effects.

A few references:

Nokali, Bachman, & Votruba-Drzal (2010). Parent Involvement and Children's Academic and Social Development in Elementary School. *Child Development*, 81(3), 988–1005.

Senechal & LeFevre (2002). Parental Involvement in the Development of Children's Reading Skill: A Five-Year Longitudinal Study. *Child Development*, 73(2), 445-460.

Rayner, K., Foorman, B. R., Perfetti, C. A., Pesetsky, D., & Seidenberg, M. S. (2001). How Psychological Science Informs the Teaching of Reading. *Psychological Science in the Public Interest Monograph*, 2, 31-74.

Ehri, Nunes, Stahl, & Willows (2001). Systematic phonics instruction helps students learn to read: Evidence from the National Reading Panels meta-analysis. *Review of Educational Research*, 71, 393–447. \[Note: there has been some statistically complex back-and-forth regarding this report, but I believe the original finding still stands.).
> 7 votes

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Tags: learning, developmental-psychology, reading
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# Question
Title: What does daytime actigraphy reveal about an active and awake brain?
I have interest in the study of human motion ( Actigraphy), and have built a couple of smartphone apps using its principles. The apps look at gross motor activity of an individual. Up until now, most of my reading into the field has been focused on the study of sleep. With Actigraphy, there are clear ~90 minute activity patterns visible over the course of the night that roughly correlate with the 4 stages of sleep. There are algorithms by Cole and Sadeh which describe how to score sleep using activity counts.

* **Are there any uses of actigraphy for awake patients?**
* **Are there any investigations of the correlation between the overall activity pattern/level and the brain wave frequency (alpha/beta/...)?**
* **Are there any wake-related actigraphy algorithms?**

**Update** thank you for answers and comments! Let me clarify the question. I'm interested in comparing a rather long history of events for the same individual wearing an actigraph.

For example we have a person who's both an athlete and also does meditation. I'm interested in using actigraphy to determine the length of the meditation sessions, along with any increase/decrease of overall activity pattern that may accompany meditation activity (ex: deeper concentration moves the brain to a different brainwave and relaxes the body, or nervousness and fidgeting rising, the person cannot get to the correct brainwave and cuts the session short).

Lets say the same person is a runner. Wearing an actigraph during sessions displays two important characteristics: When the person is and is not running. (going out to run is an action that requires conscious action. How long the person is running. If a person is feeling "negative", the person may not go out to run). If a person does go out to run, the running session may be cut short if a person is not in the right state of mind.

**Combined with self-reported events (ex: running session started, meditation session started), such actigraphy data may be plotted day by day. I'm interested if there have been studies of such data.**

# Answer
> 6 votes
It's obvious that people will move more when awake or doing exercise compared to being asleep or resting, however actigraphy provides a quantitative way to measure that. Therefore actigraphy is useful for studying sleep-wake cycles, activity-rest cycles and circadian rhythms. They have been shown to be reliable in determining when a subject is awake or asleep, so that's why they are generally used for that. Although there still needs to be more standardization and consistency of analysis and reporting in scientific literature to make comparison between studies more useful (Berger et al., 2008).

In order for actigraphy to be useful for understanding brain activity while awake, there needs to be a way to monitor brain activity. When exercise is involved methods such as fMRI, PET, TMS are not suitable since subjects need to stay still. EEG and EMG are really the only options. Winkler et al., 2003 has correlated short-term actigraphy with awake EEG patterns, and results suggest that they can be used to indicate CNS arousal. It probably doesn't affect the results, but you should note that the study was with psychiatric patients who were taking medication. It would have been more thorough to do this with normal population as a control to ensure generalizability. The software/algorithm they used was "Actiwatch Sleep Analysis 2001" (Cambridge Neurotechnology). Maybe you can look that up to find out more, although I'm not sure the algorithm would be published.

### References

* Berger, A.M., Wielgus, K.K., Young-McCaughan, S., Fischer, P., Farr, L. & Lee, K.A. (2008). Methodological challenges when using actigraphy in research. Journal of pain and symptom management, 36, 191-199.
* Winkler, D., Pjrek, E., Pezawas, L., Presslich, O., Tauscher, J. & Kasper, S. (2003). Relationship between power spectra of the awake EEG and psychomotor activity patterns measured by short-term actigraphy. Neuropsychobiology, 48, 176-181.

# Answer
> 4 votes
Using activity monitors on awake patients is very domain specific. You need to equate them on some activity parameters and then look at how the individuals vary across some domain. For example, you could monitor athletes and correlate the amount of physical activity with performance. Or, you could monitor grade school children and look at something like childhood obesity.

So no, some general classifications based on Actigraph patterns are not done on awake individuals. Daily activities vary greatly across awake individuals while sleep has very defined patterns of behaviour.

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Tags: neuroscience, experimental-psychology, sleep
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# Question
Title: A study about preference for making relatively vs. absolute more money?
I remember reading about a study. I forgot the actual details of it, but the gist of it was: people were asked in what situation they would prefer to live, one where they make \\$100,000 dollars and the neighbours all make \\$200,000 dollars, or one where they make \\$10,000 dollars and the neighbours all make \\$5000 dollars. Most participants chose the \\$10,000 vs \\$5,000 situation, even though they would have ended up with much less money (note: I am pretty sure I got the actual numbers wrong).

Sadly, I don't remember where I read it (thought it must have been in Predictably Irrational, but can't find it there).

### Questions

* What is the reference for the study
* What theories explain this behavior?
* Where can I read background information on the topic?

# Answer
I've found Neighbors as Negatives: Relative Earnings and Well-Being by E.F.P. Luttmer (2005), although I'm not sure it's the right one. I've heard about your study as well, but I thought it was older than 2005. You can read the study I linked and look up the references. There are quite a lot that touch the same subject.
> 6 votes

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Tags: reference-request, decision-making, economics
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# Question
Title: Need good example of two domains involving different procedural knowledge yet sharing same high-level strategies
Working in the domain of intelligent tutoring systems, I have to prove (or disprove) that explicit teaching of high-level strategies will allow students to use learned strategies across different domains.

I implemented a tutorial system teaching the best way to add a sequence of natural numbers. The procedural knowledge here is being the addition process, and the higher level strategy is choosing the order of the numbers to add. Another tutorial system implemented is a system teaching the reduction of boolean expressions. The procedural knowledge here is the application of the different boolean reduction rules, and the higher level is the wise choice of the rules to apply to obtain an effective reduction with minimum steps.

Yet these two domains are too different to have the same strategies, unless we use very abstract terms (e.g. "start with the easy parts"). What I desperately seek is two rather simple teachable domains which would be different enough to have different procedural knowledge, yet similar enough to have a set of common explicit strategies. I guess the answer would be in the domain of physics and/or math. I could also examine "fake" domains, i.e., domains that exists solely to prove my point mentioned earlier.

# Answer
> 2 votes
I think *"teaching of high-level strategies will allow students to use learned strategies across different domains"* is the very rationale of mathematics. Math gives very good examples of both abstract strategies for solving problems across different domains and also specific, explicit strategies. You don't seem to want the abstract strategies, but if you change your mind on that, George Polya's How to Solve It is one of the best books on this topic.

Your other constraint is that the domains should be simple, otherwise differential equations or graph theory would be great examples of explicit solution strategies having applications across multiple domains.

I guess something that will meet your needs well is linear algebra and, in particular, solution strategies for systems of linear equations.

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Tags: learning, cognitive-modeling, problem-solving, artificial-intelligence
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# Question
Title: How can STDP fit with reciprocal connectivity?
I have rather technical question regarding STDP dynamics. I am working on a neural network implementing an STDP learning algorithm, and have noticed that it is extremely anti-reciprocal. When two neurons have bidirectional connectivity between them, the conditions that will strengthen one direction will inevitably weaken the other, as far as I can understand. If B consistently fires immediately following a spike in A, the A-\>B synapse will strengthen, however the B-\>A synapse would weaken, as the pre-synapse / post-synapse roles are reverse. This wouldn't be much of a problem if it weren't for empirical evidence of high reciprocity in cortical connectivity.

**Am I missing something? Is this a known shortcoming of the model?**

# Answer
Consider that elimination of such a phenomena is not ideal. It's been proposed that actual neuronal networks exist under the tension of synchronous decoupling.

http://www.sciencedirect.com/science/article/pii/S0896627308001281

To answer your question though, you probably should consider that reciprocal connections might not be between two individual neurons. Rather, axons in the cortex are clumped into minicolumns, each one having 20+ pyramidals in supragranular layers. It's conjecture, but it's possible that the reciprocal connections are between different pyramidals within minicolumns (or even different pyramidals within columns or whatever other macro-structure you want).
> 2 votes

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Tags: computational-modeling, theoretical-neuroscience, neural-network, connectionism, plasticity
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# Question
Title: When is it best to use PsycINFO versus Google Scholar?
PsycINFO is a abstracting service provided by the APA dedicated to research in the behavioural sciences to which many universities subscribe. Google Scholar provides a free abstracting service that covers seemingly all areas of research.

* **What are the pros and cons of using PsychINFO versus Google Scholar?**
* **Under what conditions should someone use one or the other service?**

# Answer
# Benefits of PsychInfo

* PsychInfo has more accurate metadata.
* PsychInfo permits more controlled search terms over that metadata.
* PsycInfo makes it easy to download a set of references. Without using third party tools Google Scholar only exports one reference at a time (as far as I am aware).
* PsycInfo contains abstracts for quick browsing. Google scholar requires you to follow a link to the publisher to get the abstract.
* PsycInfo lists references and cited-by whereas Google Scholar only has cited-by.
* The version of PsycInfo that I use through ProQuest has an option to export formatted references in a range of bibliographic styles.
* Both support full text integration. I've often found more one-click access to PDFs in PsycInfo. However, Google Scholar will let you know if a PDF is freely available on the Internet.

# Benefits of Google Scholar

* Google Scholar is free to use. So naturally if you don't have access to PsychInfo, then it is there.
* Google scholar includes more content from more disciplines. But PsycInfo has great coverage of psychology.
* Google Scholar does not require a password to access.
* Google Scholar is quicker to start. For example, at my university, you need to go to find and go to the library site, find the page that allows you to search for databases, search for 'psycinfo', log-in. This can typically take 10 to 20 seconds. Bookmarks and saved passwords speed up the process considerably. Nonetheless, with Google Scholar I can get started with a search in 2 seconds. And the search flows naturally from a regular Google search. If all I want to do is get a single article or get a quick sense of what research has been done on a topic, that speed is important. Of course, for longer sessions, this time is no big deal.
* Google Scholar has efficient BibTeX citation export.
* Google Scholar has "related articles" that generates interesting suggestions.
* Google Scholar sessions don't time out. PsycInfo sessions do time out. Thus, if you are moving between searching, reading, and other activities, this time-out on PsycInfo is a nuisance.
* Google Scholar makes it easy to obtain an APA formatted citation for a given reference.
> 3 votes

# Answer
At the rate the literature grows and journals proliferate, it is often hard to keep up with current trends. I find one of the best way to do this is to follow specific researchers that have research interested similar to me. Google Scholar allows authors to create profiles that collect their papers automatically.

Researchers on Google Scholar: Psychology, Neuroscience, and Psychiatry.

If you go to one of the authors' profiles, then you can click `Follow new articles` and Google will send you an email when they publish; I've found this incredibly useful.

In a similar vein, you can select `Follow new citations`, this is not as useful for other authors (unless your research interests are *really* similar) but you can do it for your own account to get email notifications when someone publishes something extending your previous work.

If you want some breadth, then Google Scholar recently introduced a feature of personal suggestions. This does some basic machine learning on your publications and their position in the citation graph to suggest papers you might be interested in. I have tested this feature out, and it is pretty interesting. It suggested a number of papers (mostly experimental biology) that are relevant to my research but I would not have found otherwise.
> 3 votes

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Tags: publication-process
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