# Question
Title: Quantifying chromatic adaptations made by the brain
What are the ways one can use to measure the kind of adaptations done by the brain to provide colour constancy? Has this been done before?

# Answer
> 1 votes
You have specifically asked about the "**adaptations done by the brain**" in your initial question and an interest in "**what has been done towards finding the formula and what it was replaced with for the time being?**" By formula, I'm assuming that you meant a perceptual algorithm that can be useful in machine learning and the attempt to reverse-engineer human's perceptual systems.

Yes, there has been extensive work done on this. I cannot give you an extensive answer on this platform, but hopefully point you towards the right direction. I have mentioned two papers and their abstracts, the former is more accessible, and the later in case you want a sneak-peak of the mathematical methods involved in making a computational model of color constancy and chromatic adaptations.

On the other hand, if you're new to this or you want to simply refresh your memory - I have attached my ex-Professor's notes from a Perception class I took a few years ago to give a clearer idea. **It might just be best to first read through those first, in which case you should skip the first two papers I have mentioned.**

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Sensory, computational and cognitive components of human colour constancy.
Smithson H.
Philosophical Transactions of the Royal Society, Biological Sciences. 2005; 360(1458): 1329-1346.

> **Abstract**
> When the illumination on a scene changes, so do the visual signals elicited by that scene. In spite of these changes, the objects within a scene tend to remain constant in their apparent colour. We start this review by discussing the psychophysical procedures that have been used to quantify colour constancy. **The transformation imposed on the visual signals by a change in illumination dictates what the visual system must ‘undo’ to achieve constancy. The problem is mathematically underdetermined, and can be solved only by exploiting regularities of the visual world. The last decade has seen a substantial increase in our knowledge of such regularities as technical advances have made it possible to make empirical measurements of large numbers of environmental scenes and illuminants.** This review provides a taxonomy of models of human colour constancy based first on the assumptions they make about how the inverse transformation might be simplified, and second, on how the parameters of the inverse transformation might be set by elements of a complex scene. Candidate algorithms for human colour constancy are represented graphically and pictorially, and the availability and utility of an accurate estimate of the illuminant is discussed. Throughout this review, we consider both the information that is, in principle, available and empirical assessments of what information the visual system actually uses. In the final section we discuss where in our visual systems these computations might be implemented.

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Color constancy using natural image statistics and scene semantics.
A. Gijsenij and T.Gevers.
*IEEE PAMI*, 33(4):687–698, 2011.

> **Abstract**
> To achieve selection and combining of color constancy algorithms, in this paper natural image statistics are used to identify the most important characteristics of color images. Then, based on these image characteristics, the proper color constancy algorithm (or best combination of algorithms) is selected for a specific image. To capture the image characteristics, the Weibull parameterization (e.g., grain size and contrast) is used. It is shown that the Weibull parameterization is related to the image attributes to which the used color constancy methods are sensitive. An MoG-classifier is used to learn the correlation and weighting between the Weibull-parameters and the image attributes (number of edges, amount of texture, and SNR). The output of the classifier is the selection of the best performing color constancy method for a certain image. Experimental results show a large improvement over state-of-the-art single algorithms. On a data set consisting of more than 11,000 images, an increase in color constancy performance up to 20 percent (median angular error) can be obtained compared to the best-performing single algorithm. Further, it is shown that for certain scene categories, one specific color constancy algorithm can be used instead of the classifier considering several algorithms.

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Below are examples of a few experiments that can be played out from behind your computer screen:

From Jonathon Winawer's notes on Perception:

> **Color Constancy and Chromatic Adaption**
> Take a photograph under fluorescent light, and compare it to the same picture under daylight. The colors come out totally differently - greenish under the fluorescent light and reddish under daylight - unless you do some "color correction" while developing the film.
>
> But you wouldn't see it that way if you were in the room. To you the colors would look pretty much the same under both illuminants. This phenomenon is called color constancy, analogous to brightness constancy that we discussed earlier. The eye does not act like a camera, simply recording the image. Rather, the eye adapts to compensate for the color (SPD) of the light source.
>
> Above is another example of a pair of photographs taken under different lighting conditions without color correction. The physical characteristics of the light reaching the camera is very different depending on the color of the illuminant. This results in dramatically different photographs. But if you were there when the pictures were taken, this object would look pretty much the same to you under both illuminants.
>
> Glance at the penguin and dragon pictures above by fixated on the dot between them. The penguin picture looks very blueish and the dragon looks very yellowish. Next, you will hold your gaze on the dot between the blue and yellow fields. Continue staring at that dot for 30 secs or so. Then look back at the penguin and dragon by fixating the dot between them. What do you see? Why? The change in percept following adaptation is due to chromatic adaptation. Chromatic adaptation is like light and dark adaptation but instead of adapting just to light and dark, it adapts to whatever the color is of the ambient illumination.
>
> Each cone type adapts independently. For example, a given L cone adapts according to local average L cone excitation. Likewise for the M cones. Thus, the retinal image adjusts to compensate not only for the overall intensity of the light source, but also to compensate for the color of the light source.
>
> Chromatic adaptation, like light adaptation, can give rise to dramatic aftereffects. For example, adapt to this green, black, and yellow flag for 60 secs, then look at a white field and you will see an afterimage of a red, white, and blue flag. Red/green, blue/yellow, black/white are complementary colors. Normally, when you look at a white field, L and M cones give about the same response so the red/green opponnent colors mechanism does not respond at all. If you adapt to green, the M cone sensitivity is reduced. Then, when you look at a white field, the L:M cones are out of balance; the L cones are now more sensitive than the M cones so the red/green mechanism gives a positive response and you see red instead of white. This only lasts for a couple of seconds because the M cone sensitivity starts to readjust right away. The visual system is designed to try to achieve a perceptual constancy. But, as with the various brightness illusions I showed earlier, color adaptation also results in some misperceptions. The colored afterimage is an undesirable consequence of chromatic adaptation coupled with color opponency. Usually chromatic adaptation does the right thing, it compensates for the color of the illuminant.

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Tags: perception, measurement, color, psychophysics
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# Question
Title: How many possible states does a brain have?
Suppose I have a box, inside of which is a light which can be either on or off: it has exactly two states.
Suppose I wanted to take some "snapshot" of the state of this device, and store all the information about it, so that if I at some point had another device with sufficiently identical hardware + environment and a way of writing all the state to that device, I could recreate the state of that box. There are n=**two** possible states (so it would require log2(n) = 1 bits to store the state).

Now suppose my box is a brain. **To the nearest order of magnitude, how many possible states does the brain have?**

Assuming it's an adult human brain might make for the most useful answer to this question, but if you have more solid answers for brains of other animals while we wait on an answer for humans, feel free to post an answer stating that assumption.

# Answer
# 2 2,752,000,000,000,000,000,000 states

> Disclaimer: This is obviously a very crude and imprecise estimation (in fact, it is ignoring some obvious parameters for the sake of simplicity). As Scott E. Page puts it: Even models that are far from accurate can teach us something.

If one considers the design of future artificial brain, you can make these rough assumptions:

* A 32 bit floating point representation should suffice to capture synapse elasticity.
* There are about 86 billion neurons in the brain. The connectivity of which can be represented by a square matrix of size 86 * 1018 (86 * 109 to the power of 2). Each connection is weighted, 32-bit float.

Resulting in 86 * 1018 * 32 bits =

2752000000000000000000 bits (2.75 sextillion).

These many bits result in these many states:

2 2752000000000000000000

or:

This obviously a very rough estimation - you don't account, for example, to membrane potential, although you can argue that discarding membrane potential while maintaining neural connectivity and synaptic strength should suffice to 'reignite' a frozen brain.

Perhaps more importantly, a network structure can be represented by a matrix, but more often is represented by a sparse matrix - no neuron is connected to all other neurons, I believe 1000 is the average and some sources state that there are about 1,000 trillion synaptic connections.
> 3 votes

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Tags: neuroscience, cognitive-neuroscience, theoretical-neuroscience, neural-network, neuroimaging
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# Question
Title: How long does it take for electrical impulses from neurons to travel in the human brain?
Consider the maximal distance between two separated areas in the human brain. How fast can information via neuronal excitement travel between these two locations?

# Answer
This is hard to say because not as many studies measuring this in humans have been done as have been done in other primates, like macaque monkeys, and when it is done, it is usually done in patients who have some brain issue like epilepsy and have recording electrodes implanted for preparation for a procedure, and so may not have a typical response. Also it is hard to know how best to satisfy your requirement "the maximal distance between two separated areas in the human brain".

That said, here's my attempt: **about 25 to 30 ms.** I get this from two sources:

1) a 1983 paper using epileptic patients with microwire electrodes in their brain at various regions. I pick the data of measurements of the visual response arriving in the occipital lobe because--thinking simply--it is at the back of the head on the other side of the head from the eyes, and so the "maximal distance" is the entire front-to-back length of the brain (the pathway being retina -\> thalamus -\> V1 of visual cortex). From the paper (page 490, bottom):

> Occipital Lobe Units: Using diffuse flash stimuli...the shortest latency of the 11 responsive occipital cortex cells was **31 ms**; the mean latency was 63.6 ms (range, 31 to 110 ms, SD, 25.1).

2) A 2009 paper, also using epileptic patients which found, among other things:

> the evoked potential started ~20 ms earlier in V1 (**25 ms** after stimulus onset;
> 2 votes

# Answer
Axons are responsible for conducting electrical impulses from the neurons's cell body. The longest axons in the human body are those found in the sciatic nerve. These axons run from the base of the spine to the big toe of each foot, and can extend up to a meter in length.

This paper attempts to get a measurement of the conduction velocity of the sciatic nerve:

Sciatic nerve motor conduction velocity study.
C B Yap, T Harota
*J Neurol Neurosurg Psychiatry*. 1967 June; 30(3): 233–239.

However, I don't think you should necessarily be equating conduction velocity with **distance**. In actuality, **conduction velocity is proportional to the diameter of an axon**. As a result, sciatic nerve neurons conduction velocity varies widely, from $0.2$ to $150$ $m /sec^{-1}$.

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Regarding axons **within the brain**, I'll be honest by saying that I don't know - you could wait for someone with knowledge about that to help answer your question. The nervous system is usually looked at as a whole. As far as the longest neurons in the brain are concerned, they are - as far as I have read - the Betz Cells in the primary motor cortex. However, that shouldn't be too useful as we are interested in inter-neuronal travel of electric impulses (or too useful even otherwise), done primarily through axons / nerve fibers. Furthermore, since I have mentioned nerve fibers (myelinated axons), you should also pay attention to insulation of the axonal membrane via myelination. Under- or over-myelination is also proportional to conduction velocity.
> 1 votes

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Tags: neuroscience
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# Question
Title: How can automatic processing be estimated in an editing task?
Is there a way of measuring/estimating the amount of controlled vs. automatic processes that takes place during a text editing task?

I know that asking participants to verbalise their actions and regard non-verbalised processes as automatic is a flawed approach. I came across the process-dissociation procedure, but this seems to refer to automatic/unconscious recollection after a learning task has taken place, and not automatic processes during the task itself.

Any suggestions of references or ideas on how to go about this?

# Answer
> 1 votes
What do you mean exactly with 'processes'? If you're thinking about actual movements made during editing (i.e. tiping), this science paper might help. Very simply put, they showed skilled typist have two kinds of control processes, one conscious and one unconscious.

(Science 29 October 2010: Vol. 330 no. 6004 pp. 683-686 DOI: 10.1126/science.1190483)

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Tags: consciousness, unconscious, automaticity
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title: What if swarm of ants is a metamind?

text:
# Question
Title: What if swarm of ants is a metamind?
It is obvious that single ant is a being but what if swarm of ants is another kind of being? Do you have ideas how we could communicate with it?

# Answer
> 2 votes
Good question, and no one really has a definitive answer, but it is generally considered that a system, as you described, is not a metamind as you call it, or a singular being.

First lets define what a being is:

A being is a system that works together to collectively maintain all characteristics of life. These are:

* being made up of cells
* the ability to reproduce
* the ability to react to a stimulus
* Organization
* Metabolism
* Growth
* adaptation

A swarm of ants contains all of these characteristics, so it could be classified as a 'being'.

Though the problem is that the reactions and actions taken by a swarm of ants is not considered as adaptable or as self sufficient as a single being. For example colonies of ants are able to effectively create short paths, though this is due to the physiological structure of the ant colony itself, and not its intelligence. Artificial ant networks are based off this structure, is this simulation a metamind too?

Another scenario to consider is if you placed an ant colony in a particular unknown situation. Would the ant colony be able to fight off predators, look for food and other life related characteristics? Ant colonies do not particularly work in this fashion.

This problem casts doubts as to whether an ant colony is a metamind.

On the other side of the coin though, the mind body problem has not been resolved and therefore there is no definitive answer to your question. For example monism states that consciousness is singular.

Overall though a swarm of ants is not considered a 'being' or a metamind in contemporary psychology.

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Tags: intelligence
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# Question
Title: Analysis of parameter estimates from Ratcliff diffusion model
I would like to analyze a dataset in which subjects' reaction time and error rate have been recorded. In order to account for potential speed-accuracy trade-off I am planning to make use of the Ratcliff's diffusion model. My data is a within-subject repeated-measures design with two sessions per subject (drug & placebo) with multiple measurements in each session (around 80).

While reading some papers regarding this topic I found a nice report by Wenzlaff et al. (2011). First they fit the diffusion model for every subject and then take the estimated parameters to an ANOVA. However I was confused by their approach: it seems they select the best fitting model for every subject and in this way are fitting models with different parameters for the subjects. My understanding was that it is not a valid approach to put together estimates from models with different parameters?

My questions are:

* Would it be a valid approach to first fit the diffusion model separately for every subject and then take the estimated parameters to a group-level analysis (e.g. repeated-measures ANOVA)?
* Prior to ANOVA of parameter estimates: is it - in the above context - better to fit the same model to all subjects or to select the best fitting model for every subject?

> Wenzlaff, H., Bauer, M., Maess, B., & Heekeren, H. R. (2011). Neural characterization of the speed–accuracy tradeoff in a perceptual decision-making task. The Journal of Neuroscience, 31(4), 1254-1266.

# Answer
> 6 votes
**Using Parameters Estimated from an Individual in a Group Analysis**

In a way this is exactly what usually happens when we calculate the mean reaction time across all conditions for a group of participants. When we normally calculate mean reaction times we assume that some process (P) takes t milliseconds to complete plus some Gaussian distributed noise. We want to estimate this parameter (t) across conditions, to make some statement about how the treatment effects processing. Then we calculate this set of parameters for a number of participants to ensure that we are looking at something interesting at the population level.

However, we can adopt more sophisticated models with more parameters that better represent how reaction times actually vary. Take the simple case of the ex-Gaussian distribution. This distribution is the combination of an exponential distribution and a Gaussian distribution. The shape of an ex-Gaussian is much closer to a distribution of observed reaction times than just the Gaussian alone. Reaction times modelled with an ex-Gaussian involve fitting two parameters; one for the Gaussian and one for the exponential components of the model. So in this case we would calculate these parameters for each condition and participant. Then we would enter these sets of parameters into two repeated measures ANOVAs; one for the Gaussian parameters and one for the exponential parameters. Then we can assess whether the treatment alters how the reaction times vary. The problem with the ex-Gaussian is that the two parameters have no psychological basis, so there is no meaningful interpretation of the treatment effect on these parameters.

This is where diffusion models are useful because the parameters in the model are psychologically meaningful, allowing us to make interesting inferences from changes in the parameters across conditions.

**Same Model or the Best Model or each Participant?**

I'm no expert with diffusion models, but I would expect that the same model should be applied to each participant. Not doing so would mean that you are assuming a different model for your reaction time distributions across participants.

# Answer
> 1 votes
HDDM allows to fit a *hierarchical* drift diffusion model and gives you the posterior of the group effects.

That means, the model is fit for all subjects simultaneously. Subjects are allowed to vary, but an underlying shared effect is assumed (and the same model is fit for all subjects, although of course a parameter may end up as 0 for a subject). The model is Bayesian and the results are directly interpretable as Bayesian inference.

It's in Python.

# Answer
> 0 votes
If you are planning on comparing the parameters, then you should apply the same model. However with only 80 observations per session per subjects you might need to use hierarchical bayesian framework, because sequential sampling models are pretty unstbale with so few observations.

Here is a nice paper on combing RT models with neural data using hierarchical bayesian framework: http://www.newcl.org/publications/TurForWagBroSedSte13.pdf

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Tags: methodology, statistics, reaction-time
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# Question
Title: Are there any studies that were able to localize Fusiform Face Area (FFA) for face processing using EEG source localization algorithms?
I am looking for references where people were able to collect 128-256 channel EEG data during face perception task and the map it onto FFA or OFA using source localization algorithms?

# Answer
The N170 (the face selective component of the brain) is commonly mapped indeed to OFA or FFA. It's trivial to find examples for this, e.g.: this, this, this, this, this. Many more studies can be found by searching the relevant data bases, e.g. like this. Some of these include co-registered EEG/fMRI or MEG. There is some uncertainty of where exactly it originates from - OFA, FFA, both.

Note that dipole fits can be seen as leading to oversparse solutions - they might locate the N170 to one out of OFA or FFA, when it is actually projected by a larger are including OFA, FFA, and possibly even more of the cortex.
> 2 votes

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Tags: perception, eeg, neuroimaging
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# Question
Title: Selective Attention v. Sensory Adaptation
I'm currently taking AP Psychology and we recently learned about sensory adaptation and selective attention. I was just wondering if there is any actual difference between the two? They seem pretty similar to me. Any clarification is appreciated.

Thanks!

# Answer
> 3 votes
Sensory adaptation is very low level and completely subconscious.

Selective attention is pretty much as high level you can get before hitting consciousness.

The two mechanisms work on a polar ends of the stick.

# Answer
> 3 votes
It is rather difficult to answer this question without knowing what you mean by these two terms (both are used in a variety of contexts, and there is still debate about their precise definitions). The "low"/"high" level distinction identified by Izhaki is not universally accepted. It might be better if you were to explain why you think they are "pretty similar".

The most common understanding of "selective attention" is as a "filter", which prioritises the processing of some stimuli (e.g., a particular voice at a party, or a particular spatial location in a visual task). The wikipedia pages on attention have a reasonable summary of this. Importantly, we can selectively attend to something voluntarily (i.e., it is partly under conscious control), although in some circumstances our attention is also "captured" by distraction even when we don't want it to be.

"Sensory adaptation" can mean several things (for example the adaptation might refer to adaptation thanks to evolution, or to the way that our eyes grow accustomed to darkness). In current experimental psychology, the most common meaning of sensory (also neural or perceptual) adaptation is when the same, repeated stimulus evokes a different response. This may be because sensory neurons habituate, but it may also happen at the level of the cortex, and so in psychophysics it is a useful tool for learning about more complex representations. There is also a wiki article on this here.

One way in which adaptation and attention are similar is that both can modulate the response to particular stimuli (sometimes called changing the "gain" when talking about neurons). One way in which they are different is that selective attention is normally beneficial (it boosts processing), and requires conscious instructions or manipulations rather than simple repetition.

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Tags: cognitive-psychology
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# Question
Title: What is the name for the cognitive bias that ignores that extreme symptoms always tend to get less extreme?
There are some long term diseases where the severity of your symptoms tend towards a 'normal'. So imagine plotting out the severity of the symptoms say, every day or every week, then drawing a line of best fit through them.

So over the long term, severity may change slowly. However in the short term, statistically speaking, it'll tend to be that if symptoms have been super bad for a short while, it'll tend to get better. And if symptoms have been very good for a short while, it'll tend to get worse.

There's a name for this trend. I'm not sure if it's actually a cognitive bias, it could be more of a statistical fallacy type thing. I can't remember the name... and I've searched for it in every way I can think of in google but no luck. I originally read about it in the context of pseudoscience treatments. So someone has a long term condition, they have a very 'bad year', they go see say... a homeopath, and then they get a bit better and they ascribe their improvement to the homeopathy where as in fact, statistically speaking they were likely to have gotten a bit better on their own.

# Answer
> 1 votes
The statistical phenomenon you are referring to is called **regression to the mean**. It describes the fact that extreme measurements which are affected by random fluctuation will tend to be closer to the average in subsequent measurements. This phenomenon is not limited to clinical symptoms but occurs for any measurement that is selected for its extremity.

As an example, you let students take two tests that are designed to assess the same underlying aptitude. Then you look at the 5% best and the 5% worst performers in the first test. In the second test, the score of the high performing students will likely drop to some extent and the score of the low performing students will likely rise to some extent, even though the aptitude has not changed. This is because the test results are affected by random variation (they are not perfectly correlated) that is independent from the aptitude.

The failure to take statistical regression into account gives rise to the so-called **regression fallacy**. The regression fallacy refers to the tendency to attribute the change of extreme scores to spurious causal reasons. As a frequent example, if a football team loses some games and fires the coach, subsequent increases in performance may be explained with this fact even though it was just due to chance.

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Tags: terminology, clinical-psychology, statistics, bias, regression
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title: Can memory access be detected via fMRI?

text:
# Question
Title: Can memory access be detected via fMRI?
Can the use of memory, in it's various forms (working memory, procedural, semantic), be detected and distinguished from one another via fMRI?

# Answer
In theory, yes, because there are now many theories, supported by evidence, which map different memory processes onto different regions and patterns of activity in the brain.

In practice, there are many difficulties with doing this. First, it would depend on what stage or process you are thinking of (are you considering encoding? or retrieval?). Second, many subtypes of memory are defined according to the stimulus (for example whether you are remembering facts or actions), and so differences in brain activity might be due to the stimulus and not the process per se. Thirdly, fMRI has limitations which might make it difficult to isolate the relevant differences, especially if you were trying to do this on a trial-by-trial basis or if you were looking at subcortical structures.

There are plenty of papers which try and address this. For example, here is one looking at dissociations within recognition, here is one in Alzheimers and here is an influential review.
> 4 votes

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Tags: memory, fmri
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# Question
Title: 432 Hz vs. 440 Hz frequencies: health and psychological effects?
Search for “432 Hz” in YouTube and you’ll find plenty of examples where people have applied a pitch shifter to alter music ranging from a Mozart Requiem to Oasis’ Wonderwall.

But some claim that there is more to this than just preference. There are several blogs that claim that using a normal concert tuning of 440 Hz is bad for our health, but then what do you expect from something first promoted by the Nazis?

> The recent rediscoveries of the vibratory / oscillatory nature of the universe indicate that this contemporary international concert pitch standard may generate an unhealthy effect or anti-social behavior in the consciousness of human beings … There is a theory that the change from 432 Hz to 440 Hz was dictated by Nazi propaganda minister, Joseph Goebbels. \[Source: Zen Gardner.\]

Also,

432 Hz is said to be mathematically consistent with the patterns of the universe. Studies reveal that 432hz tuning vibrates with the universe’s golden mean PHI and unifies the properties of light, time, space, matter, gravity and magnetism with biology, the DNA code and consciousness. When our atoms and DNA start to resonate in harmony with the spiraling pattern of nature, our sense of connection to nature is said to be magnified. The number 432 is also reflected in ratios of the Sun, Earth, and the moon as well as the precession of the equinoxes, the Great Pyramid of Egypt, Stonehenge, the Sri Yantra among many other sacred sites.

> “From my own observations, some of the harmonic overtone partials of A=432hz 12T5 appear to line up to natural patterns and also the resonance of solitons. Solitons need a specific range to form into the realm of density and span from the micro to the macro cosmos. Solitons are not only found in water mechanics, but also in the ion-acoustic breath between electrons and protons.”

– Brian T. Collins

Another blog wrote that,

> The noticeable difference music lovers and musicians have noticed with music tuned in A=432 Hz is that it is not only more beautiful and harmonious to the ears, but it also induces a more inward experience that is felt inside the body at the spine and heart. Music tuned in A=440 Hz was felt as a more outward and mental experience, and was felt at the side of the head which projected outwards. Audiophiles have also stated that A=432hz music seems to be non-local and can fill an entire room, whereas A=440hz can be perceived as directional or linear in sound propagation.

Also, there is a group on SoundCloud where people everyday shares different sound tracks based on 432 Hz frequencies.

It is still kind of ambiguous and unclear to me. Does it really work to tune your music to 432 Hz, or it is just a hoax? Does it really effect your sub-conscious state and your health?

# Answer
> 9 votes
One of the claims that is somewhat easy to validate empirically is that "432 Hz sounds better than 440 Hz." This informal experiment tests this in a straightforward way. People listen to pitch-shifted versions of songs at a variety of different frequencies and rate their preference for the song. Importantly, they don't know which frequency the song has been shifted to.

The results pretty clearly debunk the claim that 432 "sounds better" than 440:

The preference ratings were highest at 440, and there was no statistical difference between 432 and 440.

# Answer
> -4 votes
I am a pro musician .... yes i agree that similarity and 'content' in any alleged 'blind' study sample will manifest a relevant INACCURATE difference in results. This has to be done with PET or other diagnostics to arrive at the correct conclusion.

However, as far as 'sacred' or metaphysical......the shape of the cochlea in the ear (natural biologic resonation chamber) and the mathematical science behind the theory of A-432 seems highly plausible https://www.youtube.com/watch?v=mdJinKf-lnw

The human experience detects and reacts to the subtle events...such as 8 cycles per second....IMO.....especially in prolonged exposure..such as normal modern audiophilic activities.

The experiment with the metal and the sand showing the perfectly formed patterns with A-432 I feel is conclusive to prove a dissonance exists in the tactile and biological architectural realm. Plus the body is 70% 'water' which has been shown to give the same pattern generated results.

As a Professional musician there is NO DOUBT that music effects activity and the 'pace' of human activity.....MUZAK proved that with elevators.....internal thought and healing are natural not psychic human activities so my conclusion is 'YES' A-432 is probably a better vibrational experience which most likely has deeper results in the physical body.

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Tags: well-being, music
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# Question
Title: Is there a term for behaving to the opposite extreme of a way one has been forced to behave?
I believe I'm having so much trouble figuring this out because I'm not sure what question to ask. As a few examples,

A child of an extremely religious family engaging heavily in behaviors considered unacceptable under their family's beliefs.

Someone who hates their career in an extremely analytical field switching to an extremely creative one (e.g. a software developer becoming a fashion photographer).

Reaction formation seemed to fit the bill, but that involves an extreme reaction to an unacceptable impulse rather than chronic exposure to a stressor. Compensation also doesn't seem to apply because that's a reaction to a self-identified weakness or deficiency.

# Answer
The pattern of behavior you are describing is called psychological **reactance**.

Reactance as a concept has been formalized in Jack Brehm's work in the 1960s, who has proposed a **Theory of Psychological Reactance** (1966). The theory posits that **threats to personal freedom cause motivational arousal directed at reestablishing freedom**. Consequently, the attractiveness of those behavioral choices that are eliminated or threatened can be increased.

A textbook example is a study (Brehm, Stires, Sensenig, & Shaban, 1966) in which students were promised to choose one of several music recordings. When one of the alternatives was taken away, it was perceived to be more attractive (but only when the students had the expectation that they could decide freely).

Since then, the concept has been applied to a wide variety of settings such as the role of eliminated freedom in consumer behavior (e.g., Clee & Wicklund, 1980), the persuasive effects of promotional health messages (e.g., Dillard & Shen, 2005), or patient noncompliance in therapeutic settings (e.g., Fogarty, 1997).

**References**

Brehm, J. W. (1966). A theory of psychological reactance. New York: Academic Press.

Brehm, J. W., Stires, L. K., Sensenig, J., & Shaban, J. (1966). The attractiveness of an eliminated choice alternative. Journal of Experimental Social Psychology, 2, 301–313. doi:10.1016/0022-1031(66)90086-2

Clee, M. A., & Wicklund, R. A. (1980). Consumer behavior and psychological reactance. Journal of Consumer Research, 6, 389–405.

Dillard, J. P., & Shen, L. (2005). On the nature of reactance and its role in persuasive health communication. Communication Monographs, 72, 144–168. doi:10.1080/03637750500111815

Fogarty, J. S. (1997). Reactance theory and patient noncompliance. Social Science & Medicine, 45, 1277–1288. doi:10.1016/S0277-9536(97)00055-5
> 1 votes

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Tags: social-psychology, terminology, motivation
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# Question
Title: What makes some things difficult or easy to understand?
I am thinking really deep about this topic with no answer. For example while learning `set theory` first time you find it very difficult to get your head around concepts like `Union, Intersection etc` but after some practice it becomes quite obvious, but as we go further there comes concepts like `Group theory, Abstract algebra etc` which even after reading 100 times doesn't makes any sense. On the other side you see some people playing with those concepts very easily.

Has anyone any idea on this topic?

# Answer
Firstly lets define criteria for what difficult learning material is. My interpretation of the matter states that the task of developing mastery or competency in understanding and applying difficult content:

* Takes an increased amount of time
* or Demands increased cognitive effort

It's relevant to keep in mind The 2 systems that occur in the brain

The brain is known to have a limited amount of cognitive capacity on the amount of calculations or work able to be performed, at once. This capacity is constant, unless brain development due to certain hard activities occur, in which, overtime the capacity of the brain will increase, but this happens over a long period of time(weeks months etc).

Thinking Fast and Slow by Daniel Kahneman references an experiment where demand was found to correlate to pupil dilation:

> We recorded strings of digits on beats of the metronome and instructed the subject to repeat or transform the digits one by one, maintaining the same rhythm. We soon discovered that the size of the pupil varied second by second, reflecting the changing demands of the task.

At a certain point though, the capacity of the brain is met:

> reaches an almost intolerable peak as you rush to produce a transformed string during and immediately after the pause, and relaxes gradually as you “unload” your short-term memory. The pupil data corresponded precisely to subjective experience: longer strings reliably caused larger dilations, the transformation task compounded the effort, and the peak of pupil size coincided with maximum effort.

The evidence provided strongly suggests that the theory put forward has some accuracy

According to Thinking Fast and Slow there are several factors which use up this cognitive capacity/energy, but the most important ones to consider are:

* **Multitasking** Mentally computing a series of tasks, while keeping the state of other tasks in memory. For example when multiplying 15 * 34 without a calculator, you must keep the value of 5 * 34 in your head while doing 10\* 34
* **Resisting subconscious processes** For example unlearning habits, or the Stroop effect
* **Memory** how much memory you are actively storing

These factors, which tax cognitive capacity, are ultimately the root cause of what determines the difficulty of concept, the more the learning material provokes any of these tasks, the more difficult the content is to learn.

These factors are mainly affected by two elements of knowledge: *the complexity of the knowledge*, and *how well it relates to information currently in your head*.

There are many theories on what knowledge is, and how it is interpreted by humans, including Bloom's taxonomy but the most relevant one for this question is Concept Learning which I will briefly state the 3 levels of concepts:

**Not a concept** simple recall or discrimination of knowledge

**Concrete or Perceptual Concepts** knowledge that bears physical similarity to one another from the learner.

**Defined, or relational and associated concepts** where the stimuli bears no obvious physical similarities, but cohere due to functional properties.

from not a concept -\> concrete or perceptual concepts, concepts basically grow in amount of similar or distinct properties, and abstractions; distinct physical properties, but similar functional properties.

The more properties equates to more demand for memory. The more distinct and similar properties present, the more demand for multitasking, which therefore makes complex concepts harder to understand.

In Make it Stick, a book on learning strategies suggests that humans learn content through understanding it in short term memory, but after practice, the information goes through a process of:

> consolidation, in which memory traces (the brain’s representations of the new learning) are strengthened, given meaning, and connected to prior knowledge

This point relates to **Resisting Subconscious Processes** which is described in "thinking fast and slow" tax cognitive capacity.

Also the more foreign the information is to you;the information already stored in your head, the harder consolidation will be, taking up more mental capacity.

Another consideration is *elaboration*. Knowledge is suggested to trigger the thought of other knowledge when the brain understands the relationship between knowledge. If concepts are not understood completely, and instead its information is just memorized, then this process will not occur and competency and mastery in understanding and applying the concept will be reduced. This is discussed in A Mind Of Numbers. This process not triggering will then require the logical part of the mind to figure out the connection, where the subconscious mind does not supply it, and demand more mental capacity.

So basically, the more complex information is, and the more foreign the information is, the more taxing the information will be in learning it, which makes it harder to understand.
> 1 votes

# Answer
Part of it has to do with the ability to construct a model of reality. Every developer can relate to that. Visible, concrete things are easy to deconstruct in pragmatic terms. But once you get into abstract concepts, it gets harder and harder to bind it with your existing view of the world.

Some concepts are also very difficult to grasp if you can't connect parts of the concept with things you already understand. This process is called chunking, and it can be understood as dividing the problem until each part already makes sense to you, or is small enough to tackle the question on your own.

On top of this, you have to know what you're really looking for in order to ask the right questions. Some students just ask "How does this work? I don't understand", but the teacher can't answer something so vague. Richard Feynman make a very good statement about this problem in this interview.
> 1 votes

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Tags: learning, mathematical-psychology, mathematical-ability
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# Question
Title: Why did Karl Popper criticize Freud's theories?
Why didn't Karl Popper accept Freud's psychological theories and believed that they are not scientific in essence?

# Answer
> 20 votes
I will go about this by answering two questions. First, what is Popper's general approach when attempting to distinguish science from pseudo-science? Second, what specifically did he dislike about Freudian psychoanalysis? (Historically, Popper actually developed his general theory in response to his particular dislike of contemporary marxism and Adlerian and Freudian Psychoanalysis.)

# Falsificationism

Popper proposes that in the empirical domain, nothing can ever be proved true. No swans are black because you've never seen a black swan, and you've seen thousands of swans? Well, maybe the next swan you'll see is black. This may be unlikely, but not impossible, and thus, there is no proof. (The general problem is the problem of induction, as discussed by Hume, which leads into an infinite regress.)

Thus, science is not what is proved true. Science is also not what can explain a lot of observed phenomena, because telling stories about the past is easy and always open. Instead, Popper proposes science is that which contains the means of its own refutation. Everything may be wrong, and a quality of the good ways of exploring the world is that they make clear how to see if they could be wrong. Thus, good science

* makes *bold conjectures* about how the world is like, that is, claims the world is in a state which would be surprising unless the theory were true
* derives from this *predictions* of what should never be the outcome of *experiments*
* would appears as false - *falsified* \- if those outcomes were in fact to turn up

Thus, something that is never false is unscientific, and if it claims to be science, it is pseudo-science. That which could easily be shown false, but has so far withstood many genuine attempts at falsifying it can be scientific.

A few notes: Popper did not claim that anything that is not falsifiable is bad, or false. Something may be true and unfalsifiable, and it may be good and unfalsifiable. But to claim the status of being scientific, it needs to be falsifiable.

# Psychoanalysis

Popper used to be a fan of psychoanalysis, especially of the Adlerian brand influential in Vienna in that time. His friends, he observed, were especially impressed by the ability of Adlerians to explain any and all phenomena. A man is honest? It's this kind of early-childhood event that caused this. A man is dishonest? It's that kind of early-childhood event. The Adlerians were never wrong. And it was not clear how they could ever be wrong, as they could post-hoc tell a story about how any given phenomenon fit their theories perfectly. Everything in the world was to them evidence for their theory.

This eventually came to appear to Popper as deeply misguided. Adler himself, with whom Popper worked, was exclusively telling stories about how the past proved or confirmed his theory, never claiming how a possible future state of events could disprove it. He had no predictions, and thus, no truly scientific experiments.

This made Popper not only give up on psychoanalysis, but led him to use it as one primary example of what he considered pseudo-science.

The same story also applies to Freudian psychoanalysis; between all the different complexes and drives, every possible human action or mindset could be explained as originating from childhood experiences and conflicting unconscious mental agents. But Freudians did not make bold conjectures, and did not attempt to falsify their theory with truly scientific experiments.

# Sources

Popper lays this out in **SCIENCE: CONJECTURES AND REFUTATIONS**, in the 1st chapter. It is a great read and accessibly written.

Although Popper's own words are probably the best explanation on this (as they are so clear here), it probably won't hurt to skim by the Stanford Encyclopedia for a secondary source.

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Tags: social-psychology
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# Question
Title: What is the opposite of the Bandwagon Effect?
Is there a name denoting the psychological bias where a person prefers obscure methods, things, opinions, etc. over a more popular alternative?

# Answer
> 4 votes
The term "bandwagon effect" was originally used to explain voting behavior. In 1950, Leibenstein introduced it as a concept in economics to describe changes in consumer demand:

> By **bandwagon effect** we refer to the extent to which the demand for a commodity is *increased* due to the fact that others are also consuming the same commodity. It represents the desire of people to purchase a commodity in order to get into "the swim of things"; in order to conform with the people they wish to be associated with; in order to be fashionable or stylish; or, in order to appear to be "one of the boys."

He also defined a term that describes the opposite pattern of behavior, the "snob effect":

> By the **snob effect** we refer to the extent to which the demand for a consumers' good is *decreased* owing to the fact that others are also consuming the same commodity (or that others are increasing their consumption of that commodity). This represents the desire of people to be exclusive; to be different; to dissociate themselves from the "common herd."

These definitions have coined the usage of the terms "bandwagon effect" and "snob effect" in micro-economics.

In psychology, the terms have been less relevant. Social, personality and consumer psychology have used other labels investigating people's diverging responses to social influence, such as their tendency for **"conformity"**, or their motives for seeking **"uniqueness"** (e.g., Berger & Heath, 2007; Snyder & Fromkin, 1977) and **"optimal distinctiveness"**.

**References**

Berger, J., & Heath, C. (2007). Where consumers diverge from others: Identity signaling and product domains. Journal of Consumer Research, 34, 121–134.

Leibenstein, Harvey (1950). "Bandwagon, Snob, and Veblen Effects in the Theory of Consumers' Demand". Quarterly Journal of Economics 64 (2): 183–207. doi:10.2307/1882692.

Snyder, C. R., & Fromkin, H. L. (1977). Abnormality as a positive characteristic: The development and validation of a scale measuring need for uniqueness. Journal of Abnormal Psychology, 86, 518–527. doi:10.1037/0021-843X.86.5.518

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Tags: social-psychology, terminology, consumer-psychology
---


title: Is psychology a science?

text:
# Question
Title: Is psychology a science?
I've read some books from behavioral economy to emotional intelligence, and it kind of makes sense, but when it comes to psychology it feels to me a bit like astrology, where there are some things that can work, but mostly because of auto-suggestion, or any other kind of suggestions, and things like the placebo (or even the nocebo) effect. So, I wonder if psychology is a science and why so many people rely on it.

# Answer
"Science" refers to a methodology for obtaining knowledge, and often to the knowledge itself as well. Science is often confused with another term "technology", that refers to the application of such knowledge for practical uses. Some people might incorrectly refer to "computers" and "cars" as examples of "science", when in fact they are examples of "technology".

Psychology is similarly divided. The science part is called "research psychology", or just "psychology". The technology part is called "applied psychology", that includes psychotherapy, and I think that's what this question is really about.

Clinical psychology is not technically a science, but an applied science, or in other words, a technology. If you are wondering how science-based different schools of psychotherapy are, then check out this related question: Which schools of psychotherapy are most credible to a hard scientist?. If you've seen a psychoanalyst recently for example, and you think it's kinda hoaky, well then, you're probably right - psychoanalysis is not generally considered to be science-based, and is comparable to astrology (pseudoscience) in that sense.

On the other hand, other schools of psychotherapy have a more scientific basis: Cognitive-behavioural therapy has been shown to be efficacious (above placebo) for a wide variety of common disorders, and behavioural therapy bases all its techniques directly on scientific findings.
> 21 votes

# Answer
> when it comes to psychology it feels to me a bit like astrology, where there are some things that can work, but mostly because of auto-suggestion, or any other kind of suggestions, and things like the placebo (or even the nocebo) effect. So, I wonder if psychology is a science and why so many people rely on it.

A key point is that your question seems to be leaving out is that psychology is not only about treating mental problems--it is also about **understanding the mind**. It addresses scientific questions like:

* How do children acquire language?
* What is the effect of others' actions on our own actions?
* Is intelligence one "thing", or are there multiple intelligences?
* What are the most common traits of personality?
* How do we develop our morals and/or ethics?
* How do most people make decisions?
* What is the effect of viewed violence on episodic memory?
* and so many more...

**Modern psychology, in addressing these sorts of questions, is a science.** It uses research methods like random assignment; experimental and control groups; establishing baselines; manipulating independent variables and measuring dependent variables; eliminating confounds; testing hypotheses, using statistics (*heavily!*); interacting with other disciplines, like neuroscience, anthropology, ethology, or sociology; publishing peer-reviewed papers, revising faulty models; etc.

And then, even when, in applied psychology, the intention *is* to treat mental disorders, scientific approaches are used. Treatment groups are compared with control groups, case studies are published, patients can be followed for years, behavior is measured and quantified, statistics are run, etc.

Taking a good Psychology 101/General Psychology course should make this point a thousand times over. Modern psychology should not feel anything like astrology.
> 6 votes

# Answer
As an Industrial/Organizational Psychologist practicing Human Factors in a large organization, I use scientific method to inform product and service design. Our dependent variables (effectiveness, efficiency, satisfaction, enjoyment, coolness) are measured across controlled experimental conditions. We practice stronger science than most physical scientists due to the amount of covariates in human behavior.

In answering this question as stated, one should consider the 56 different types of psychology defined by the divisions of the American Psychological Association (http://www.apa.org/about/division/).

Additionally, Wikipedia (https://en.wikipedia.org/wiki/Psychology) states that "Psychologists employ empirical methods to infer causal and correlational relationships between psychosocial variables." This is a scientific method.
> 5 votes

# Answer
Just to pick up on the following comment: **"where there are some things that can work, but mostly because of auto-suggestion, or any other kind of suggestions, and things like the placebo (or even the nocebo) effect."**

The examples you have (auto-suggestion and emotional intelligence) suggest that you've been reading "pop-psychology" books which aim to sell ideas rather than promote good science. From reading into your question, i'm guessing that its about whether psychology is actually any better at describing, explaining and predicting behaviour, when compared to a field which does this by questionable means (e.g. astrology).

The examples you picked represent fairly niche, small areas of psychology (auto-suggestion really just seems to be a pseudo-psychology buzz word not really coming from academics but business/self-help moguls).

Clearly, you can pick areas of psychology where we have been unable to correctly predict behaviour. A recent example comes from a big project on seeing how well psychology studies can be replicated (https://www.sciencemag.org/content/349/6251/aac4716.abstract) showing that the majority of published studies could not be replicated by a different research team (however, this issue isn't unique to psychology, and is often even worse in other "scientific" fields http://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.0020124).

On the whole though, lots of psychological theories that are more based on the scientific literature have been replicated and are able to predict behaviour in a variety of different contexts. Clearly using psychological theory doesn't mean you can have complete control of other people's behaviour, and often changing behaviour can be difficult. I would agree that many people rely on pseudo-scientific "psychological" theories that have been over-sold by people who want to make money, whether its through being a consultant or to just sell books. If you want a good example of how social psychology has been applied to benefit society, then i'd pick up a new book from the government's psychology unit (http://www.eburypublishing.co.uk/editions/insightful-thinking/9780753551387). There are also countless exmaples of how psychology has been better able to make us understand and treat a variety of different disorders too!
> 1 votes

# Answer
Let me first rewrite "the argument" you may find attractive/puzzling:

$Premise$ 1: behavioral economy to emotional intelligence makes sense (implying that they are "science").

$Premise$ 2: if there are auto-suggestion, or any other kind of suggestions, e.g.,placebo effect (for some thing in psychology), then some thing can work in psychology (implying some other things may not work).

$Conclusion$: Psychology does not seem to be "science", and people who rely on it seems less than sensible.

I would like to point out,

From $Premise$ 1, it seems that the way you define "science" is what "makes sense," or the way I interpret your expressed opinion is that "science" is what is intuitively convincing for (intelligible) people (e.g., yourself).

From $Premise$ 2, your expressed opinions seem to be puzzling, I am not sure what you meant by "suggestion" and "auto-suggestion." But from the example you provided, i.e., placebo effect, I conjecture that you are trying to say that psychology of some sort has pragmatic value because "suggestion" influences people. And what you may have meant but may have not expressed may be that "suggestion" seems to possess pragmatic values solely because "suggestion" $just$ influences people, and for a person as intelligible as yourself find this brute fact (that is, things like "suggestion") rather unsatisfying to study since it does not seem to lead to any pragmatic normative or empirical investigations.

Thus, you reached your puzzle, since psychology is of less pragmatic values, and less intuitively convincing, how can it be science?

I would like to note that, the term "science" can refer to different things, the meaning of this term changes throughout the history. I have not carefully read the whole page, but wikipedia seems to have some information that may help illustrate my point: https://en.wikipedia.org/wiki/Science

I would like to note that, "science" originates from the noun of the latin verb, $scire$ $(know)$. Thus, I derive that science is simply knowledge. To add on that, since that you seem to expect "knowledge" to be somewhat "empirically true," that is, to some extent, this knowledge must refer to or shed lights on how nature (including human mind) works, or how nature seems to and will be expected to work from our (future) experiences. I arrived at this notion because you credit "astrology," which seems accidental and does not conform to our experiences, as non-science.

You must have found my answer tedious and unsatisfying so far since I have only provided some clarification on possible interpretations of your question, but not an answer of why psychology is science or is psychology science.

Modern psychology seems to be empirical in nature, that is, modern psychology, to my knowledge, seems to either derived based on experiences (e.g., experiments to data to psychology theories) or developed to serve empirical investigations (e.g., theoretical psychology construed to serve as the foundation or hypothesis in empirical experiments). I would encourage you to take some look at APA approved journals or psychology articles on PubMed. I would not like you to make up your mind about psychology solely based on pop psychology books or articles for general public that are less than rigorous. Those empirical articles are quite convincing intuitively to intelligible readers like yourself. The theoretical ones, though not immediately intuitive, may make sense if you are willing to read the works this or that theory is based on and empirical articles associated with those theories.

A few things to point out based on the answer provided by the answer @Arnon Weinberg:

Hi, Arnon

1. your note on "science" and "technology" seems a bit puzzling (because your explanation on "science" though seems to be correct to some extent, your explanation on "technology" seems less than convincing) and does not seem to be necessary. Your example with "computer" for example, I would call it neither "technology" nor "knowledge." At best, maybe "theoretical computer science" is "science" and "computer science technique" is "technology" based on your definition.
2. Your way of dividing psychology based on your "technology" and "science" division seems puzzling. "clinical psychology" can be "science" even from your point of view, e.g., studies pertaining to catastrophizing influences chronic pain patient's quality of life are simply using scientific method to derive knowledge that may be of applicable value but they are not applications of knowledge.
3. your answer suddenly sabotages your own question by suggesting that what you were interested was on psychotherapy, by which, I conjecture, you mean that you real question is "is psychotherapy scientific?" This question is fine and your latter part captures this question well except that you confuse applied science with technology. By your own word, technology is the application of the science. Applied science, to my knowledge, is science that concerns application, or science of applicable value, which is $technically$ science. For example, applied math may study the normal equation to solve for the best least square solution, normal equation here is applied science. The technology, by your definition, can be a software built on normal equation, which is an application of the normal equation.
4. Another note on psychoanalysis: psychoanalytic theories nowadays are often studied by philosophy and/or history and are less received in psychology since it does not seem to be evident-based. However, there are some psychologists of psychoanalytic inclination actively conducting empirical experiments to either modify or validate $modern$ psychoanalytic theories (which is way more developed and refined than Fraud's). Also, CBT or the cognitivism and behaviorism behind other traditions of psychotherapy approach often utilizes psychoanalytic's ideas. For example, a psychotherapist of any theoretical orientation may borrow some modern psychoanalytic theories for case conception.

One final point, I think this question, though pertaining to cognitive science, may be better received in the philosophy forum since it seems to be relevant to philosophy of science and philosophy of psychology.
> 0 votes

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Tags: cognitive-psychology, terminology, experimental-psychology
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# Question
Title: In ACT-R difference between declarative and working memory
I'm currently studying PRIMs within the context of ACT-R by reading these two papers. In the papers, there are references to both declarative and working memory modules of ACT-R. What is the difference between these memory modules? Is the only difference the allowed operations on this memory and thus their use? Are there also decay effects in working memory?

# Answer
> 5 votes
This article explains the difference :

> **Declarative memory** takes the form of a semantic net linking propositions, images, and sequences by associations.
>
> The nodes of long-term memory all have some degree of activation and **working memory** is that part of long-term memory that is most highly activated.

The declarative memory is all knowledge that can be retrieved in consciousness. Working memory activates only the declarative memory needed for the current task.

When a different task is given, the activation changes to match the needs of the new task. The non-relevant active knowledge is deactivated, and new relevant knowledge is retrieved.

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Tags: memory, cognitive-modeling, working-memory, act-r
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# Question
Title: Can anyone see what is wrong with this implementation of the Pinsky-Rinzel model in Brian2?
Not sure if this is the right place to ask this but I've been attempting to implement the Pinsky-Rinzel model in the Brian2 simulator. I'm basing my implementation off the original article here: http://www.caam.rice.edu/~cox/neuro/pinskyrinzel.pdf and I've borrowed some of the formalism from the XPP version of the model here: http://senselab.med.yale.edu/ModelDB/showmodel.cshtml?model=35358&file=/b04feb12/booth\_bose.ode (Though they are shifted 60mV from where I'm working)

I've got it to replicate the somatic firing (as you can see if you set gc to zero), but I can't figure out how to get the complex dendritc and somatic interplay I'm supposed to see as seen in figure 2 and figure 3 of the model and my q and Ca values don't replicate the model at all. I think there is something wrong in how I'm handling the calcium currents, or the units I'm using there.

Does anyone have any ideas of where I'm going wrong?

My code:

```
# -*- coding: utf-8 -*-
"""
Created on Sat Oct 24 11:21:30 2015

@author: Conor
"""

from __future__ import division
import numpy as np
from brian2 import *
defaultclock.dt = 0.05*ms

gbarl=0.1*msiemens
gbarna=30.0*msiemens
gbarkDr=15.0*msiemens
gbarCa=10.0*msiemens
gbarkc=15.0*msiemens

gkahp=0.8*msiemens
gNMDA=0*msiemens
gampa=0*msiemens

Vna=120.0*mV
Vca=140.0*mV
Vk=-15.0*mV
Vl=0*mV
Vsyn=60*mV
Id=0*uamp
Is=.15*uamp
gc=2.1*msiemens
p=0.5
Cm=3*uF
eqs='''
alpham=0.32*(13.1-Vs/mV)/(exp((13.1-Vs/mV)/4)-1)/ms : Hz
betam=0.28*(Vs/mV-40.1)/(exp((Vs/mV-40.1)/5)-1)/ms : Hz
alphan=0.016*(35.1-Vs/mV)/(exp((35.1-Vs/mV)/5)-1)/ms : Hz
betan=0.25*exp(0.5-0.025*Vs/mV)/ms : Hz
alphah=0.128*exp((17-Vs/mV)/18)/ms : Hz
betah=4/(1+exp((40-Vs/mV)/5))/ms : Hz
alphas=1.6/(1+exp(-0.072*(Vd/mV-65)))/ms : Hz
betas=.02*(Vd/mV-51.1)/(exp((Vd/mV-51.1)/5)-1)/ms : Hz
alphac=(exp((Vd/mV-10)/11)-exp((Vd/mV-6.5)/27))/(18.975)* (Vd<=50*mV)/ms+2*exp((6.5-Vd/mV)/27)*(Vd>50*mV)/ms : Hz
betac=((2*exp((6.5-Vd/mV)/27))/ms-alphac)*(Vd<(50*mV)) +0/ms : Hz
alphaq=clip(.00002*Ca,0,0.01)/ms :Hz
betaq=0.001/ms : Hz
Xca=clip(Ca/250,0,1) : 1
dh/dt= (alphah*(1-h)-betah*h) : 1
dn/dt = (alphan*(1-n)-betan*n) : 1
ds/dt = alphas*(1-s)-betas*s : 1
dc/dt = alphac*(1-c)-betac*c : 1
dq/dt= (alphaq*(1-q)-betaq*q) : 1
dCa/dt=-0.13*Ica/uamp/ms-0.075*Ca/ms : 1
Minfs=alpham/(alpham+betam) : 1
ILeakVs=gbarl*(Vs-Vl) : amp
ILeakVd=gbarl*(Vd-Vl) : amp
INa=gbarna*(Minfs**2)*h*(Vs-Vna) : amp
Ik_dr=gbarkDr*n*(Vs-Vk) : amp
Ica=gbarCa*s*s*(Vd-Vca) : amp
IK_c=gbarkc*Xca*c*(Vd-Vk) : amp
IK_AHP=gkahp*q*(Vd-Vk) : amp
dVs/dt=(-ILeakVs-INa-Ik_dr+gc/p*(Vd-Vs)+Is/p)/Cm : volt
dVd/dt=(-ILeakVd-Ica-IK_AHP-IK_c+gc/(1-p)*(Vs-Vd)+INMDA/(1-p))/Cm : volt
INMDA=gNMDA*Si*(1+0.28*exp(-0.062*(Vs/mV-60)))**(-1)*(Vd-Vsyn) : amp
Hxs=0<=((Vs/mV-10)*1) : 1
Hxw=0<=((Vs/mV-20)*1) : 1
dSi/dt=(Hxs-Si/150)/ms : 1
'''
neurons = NeuronGroup(1, eqs)
neurons.Vs=-4.6*mV
neurons.Vd=-4.7*mV
neurons.h=.999
neurons.n=.0001
neurons.s=.009
neurons.c=.007
neurons.q=.01
neurons.Ca=0
neurons.Si=.3
M = StateMonitor(neurons, True ,record=True,dt=.1*ms)

run(500*ms, report='text')
plt.cla()
plt.clf()
plot(M.t/ms, M[0].Vs/mV)
plot(M.t/ms, M[0].Vd/mV)
show()

```

# Answer
> 3 votes
If anyone ever finds this and has the same problem: The original paper has a flaw in the paper:

```
alphac=(exp((Vd/mV-10)/11)-exp((Vd/mV-6.5)/27))/(18.975)* (Vd<=50*mV)/ms+2*exp((6.5-Vd/mV)/27)*(Vd>50*mV)/ms : Hz

```

An errata published later changes this to:

```
alphac=(exp((Vd/mV-10)/11-(Vd/mV-6.5)/27)/18.975)*(Vd<=50*mV)/ms+2*exp((6.5-Vd/mV)/27)*(Vd>50*mV)/ms : Hz

```

After making this change it acts exactly how it should.

---
Tags: theoretical-neuroscience, computational-modeling
---