# Tag Info

10

I would go with Physics. Physicists study the world using mathematics, while mathematicians study mathematics itself which is a construct that does not necessarily exist in the real world (Albert Einstein once said: "as far as the laws of mathematics refer to reality, they are not certain; and as far as they are certain, they do not refer to reality."). ...

7

Chunking leverages long-term memory for the chunks, i.e. we recognize and remember much easier the familiar chunks, sometimes algorithmically. This is much easier explained in the domain of letters/words, e.g. we'd recognize USA as substring among random letters. Similarly most would recognize the pattern 1945 (WWII end) by paired association, or 12321 ...

6

If n != m then it will not home in on the 50 % threshold. In these simple N-up/N-down staircases, you can modify either the stepsize (as you proposed) or the number of successes/failures to act as a criterion for upgrade/downgrade. A comprehensive introduction to these staircases and the effect of changing these properties can be found in this paper. The 80 ...

6

There was a special issue of the journal Perception and Psychophysics in 2001, titled Psychometric Functions and Adaptive Methods. It contains several papers relevant to your question. Klein's paper [1] references all the others and reviews what each is about. It should serve as a good starting point. An excerpt from Klein's summary: The simple up–...

6

Now that @ofri has presented a good argument for physics, I'll give a few arguments for the benefits of a course in maths, and particularly a math course that focuses heavily on statistics. There are many areas of psychology where a good understanding of statistics is very helpful. Statistics is particularly useful in psychometrics, mathematical psychology,...

6

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

6

Psychopy (http://psychopy.org) can do this. It can do it in two ways. Using iohub. Iohub is a crazy powerful way to get any information about any kind of input to your system, from keyboard, mouse, eye-trackers, etc. You can see the documentation for keyboard here. from psychopy.iohub import launchHubServer io = launchHubServer() keyboard = io.devices....

6

There is a lot going on in your question. QUEST, as well as many other adaptive procedures, is well suited for a task like estimating morph distance in a 2-AFC paradigm. There are, however, a couple of points in your question, that make me think QUEST is not a good paradigm. The QUEST paradigm is designed around setting the signal level to find the the "...

5

In general, subjective sensation increases linearly with the the log of physical intensity, which is described by Fechner's law. We are sensitive to small variations when light is dim, but we need large differences in intensity under conditions of high luminance (Weber's law). This is a linear relation, but taken together with Fechner these findings are ...

5

Add 0.5 to the intercept and multiply the sigmoid by 0.5 since it now only spans a y-range half of before: y = 0.5 + 0.5 / (1 + np.exp(-k*(x-x0))) Generally, for any chance level: chance = 0.5 # between 0 and 1 y = chance + (1-chance) / (1 + np.exp(-k*(x-x0)))

5

There are a huge number of paradigms that SDT can be applied to. The simplest is probably the so-called yes/no paradigm. You present a single stimulus (typically noise alone or signal plus noise) and ask was the signal present. The subject if forced to respond with either yes or no. This type of paradigm typically leads to a response bias. In a 2-interval, 2-...

5

Mainly: the choice of variables. Beware that the exponent depends on the choice of parameters; or even worse - relations can change from power-law to linear, logarithmic or exponential, with redefining variables. E.g. you can measure sound volume in either amplitude, energy density (square of the amplitude) or dB (logarithm of the first one). None of it is ...

5

In psychophysics, this is known as an absolute threshold. The absolute threshold will depend on a variety of factors such as brightness, size, etc. It is also important to keep in mind that the time needed to detect a stimulus may be too short to cause some desired effect on the participant (e.g. a manipulation). For example, the time needed to detect a ...

5

You are describing two classical psychophysical techniques. The first one is called matching: you try to perceptually match stimulus J to stimulus I. The problem I can see here is that under the level of noise for which the two images are indiscriminable (called absolute threshold), any value would be a match, so that's an ambiguous task. There is another ...

4

This is an interesting methodological problem. On the one hand, it seems that any method which would present the halves to the correct eye, and only that eye, would entail a visible boundary, and any method with an invisible boundary would be unable to present the halves as desired. Virtual reality systems present stimuli to each eye separately (e.g., the ...

4

For these types of questions I really like Detection Theory: A User's Guide by Macmillan and Creelman. They consider 3 types of bias. The criterion location $c$ is calculated relative to the zero-bias point and expressed in units of standard deviations, such that a $c$ of 1 means the criterion is 1 standard deviation to the right of the zero-bias location ...

4

It is partly as you already guessed, because the phenomena that are studied don't vary as much between individuals. This doesn't necessarily mean that individual differences in perception are smaller, it means that individual differences in those aspects of perception that are studied in psychophysics are smaller. Another reason is that it is customary in ...

4

Indeed, research on this particular question is somewhat lacking, but what is available suggests that training does improve performance in tactile tests of the oblique effect. In an article published 1999, Gentaz & Rossetti lament: Unfortunately, the effect of practice on the haptic oblique effect has not been yet studied. An indication that this ...

4

Short answer Attention can be quantified with a sustained attention to response task. Background I think with focus or concentration you mean sustained attention to a certain task. A sustained attention to response task (SART) (Silverstein & Palumbo, 1998) could be helpful to you (here is a free PsychoPy script). SART seems to be a reliable measure for ...

4

Start here: Adaptive Psychophysical Procedures (Treutwein, 1995) [PDF] If you want to get fancy, I suggest a more contemporary approach for the staircase called accelerated stochastic approximation. You just need to figure out how to implement the equation and how to compute the scores, d-prime, etc. Another classic, more general (ask a librarian): https:/...

4

There are numerous studies that reveal contradictory data about face-to-face in autism. Continues the research paradigm that contrasts faces and objects. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2174902/ I think the best text I've found to get started is: this:https://psych.nyu.edu/pelli/pubs/watson1983quest.pdf Software: http://www.mas.ncl.ac.uk/~...

3

The recent visual working memory literature has predominately used the method of adjustment. In particular, there is a lot of work using continuous color adjustment tasks: Wilken P., Ma W. (2004). A detection theory account of change detection. Journal of Vision, 4 (12): 11, 1120–1135. Zhang, W., & Luck, S. J. (2008). Discrete fixed-resolution ...

3

I guess it depends on your purpose. If you are doing the MDS for more heuristic purposes, then often two dimensions (or possibly three) will provide the greatest visual insight. Also, my sense from looking at your dimension by stress plot is that the greatest gains are attained when going from one to two dimensions, that the gain from two to three ...

3

It generally helps to provide some sort of specification as to how well you want to control the timing. There are 4 orders of magnitude difference between the 100 ms timing accuracy required for auditory and visual stimuli to be judged simultaneous (Zampini et al. 2005) and the 0.1 ms timing accuracy required for binaural stimuli to be judged simultaneous (...

3

It's not exactly what you're after, but the Newcastle Cognition Lab has a data repository. It includes a number of learning curve datasets and other studies that measured response time to various simple cognitive tasks.

3

I found a paper called Summary statistics in auditory perception (McDermott, Schemitsch & Simoncelli, 2013) that might be relevant to your question. If you can't access it in full, you can a great description of the paper here. Please note that I'm writing about it from memory and that some details might not be correct. The authors had a task where ...

3

This depends on intensity but it is shorter at most intensities than your screen could possibly present a stimulus. Don't worry about it or cite references. It would be like citing a reference for why you don't need to worry about quantum effects when testing the best kind of screwdriver.

3

Research articles by Igor Dolgov (NMSU) and Mike McBeath (ASU) are good research-grade articles on this topic. They are both active scientists with well-referenced papers. I chose to work around them because of the quality of their ideas. Dolgov is more focused on Ecological perceptual models. McBeath is an illusion 'junkie'. Bother have done much work ...

3

Short answer You can try a Cedrus response pad. They are reasonably priced and my personal experiences with these boxes are good. Background Response latency (RT) measurements using standard USB input devices like a mouse or keyboard are possible, but USB devices limit accuracy. For example, the standard polling latency of any USB device is 8 msec. On top ...

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