# 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."). ...

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,...

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

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

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

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

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 ...

4

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 ...

4

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–...

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

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 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

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

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

I never read any English textbooks on psychophysics, so I cannot help you there. If I wanted to find a good one, I would look at the curricula at some universities and see which books they use or recommend. Such information is often available online. Beyond a textbook, like user1406647 (+1), I find it enlightening to read classic experiments by the ...

2

Try to find following authors and researches: Fechner, S.S. Stevens and Weber. Those experiments are easily to reproduce... New psychophysic is melted with neuroscience in some way. a/ it is easy to reproduce if you don't have expensive equipment; b/ it shows how physics and psychology shows outer and inner world respectively ie. on physics side you can ...

2

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 ...

2

Method of adjustment is still in use in vision science, especially when dealing with illusions. Its major advantage over, for example, 2AFC tasks is the speed of estimation -- you need way less trials to measure the effect, which could be useful in clinical settings [1]. You could also try to search for "nulling" instead of "adjustment" -- nulling is the ...

2

when I was planning a pilot study in which we planned to use cross-modality matching I came across some studies. Human Factors and Ergonomics researchers seem to still use the Method of Adjustment. At least, I found a couple of conference papers in which they examined warning signals for cars. Unfortunately, I don't remember the titles but I think one of ...

1

Without Potassium (K), no chemicals move. The Central Nervous System is comprised of a variety of chemicals, electrical signals and neurotransmitters to send a variety of signals through the brain and a variety of receptors of the nervous system. If you want to send a signal of neurotransmitters (medications/ or other chemicals found in your list), there ...

1

Color constancy works only if the incident illumination contains a range of wavelengths. The different cone cells of the eye register different but overlapping ranges of wavelengths of the light reflected by every object in the scene. From this information, the visual system attempts to determine the approximate composition of the illuminating light. This ...

1

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 ...

1

It is going to mean bad things. If you can only create stimuli with a predefined non uniformly sampled set of "levels" then the the corresponding percent correct that the staircase will track will depend on the threshold of an individual observer. For example, if you can create stimuli with levels of 0, 1, 2, 3, ..., 100, 110, 130, 170, 250, 410, where for ...

1

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 and a ...

1

I'm not completely sure what you ask. I give my comment as an answer, because there is more space here. I'll delete it, if you feel I'm off the mark. As far as physical theory goes (and I understand it), sound is the movement of air molecules and the resulting fluctuation in density. Measuring these density fluctuations and representing them in numbers ...

1

Those responding make some very good points about being specific about operational definitions and such. However, I've argued -- in an evolutionary psych textbook -- that there is a probably a reason why discomfort from cold and electric shock have power laws with exponents greater than perceived brightness (at low stimulus intensities), for example. It's ...

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