Questions tagged [vision]

For questions regarding the visual system, which serves to transduce light energy into neural impulses, or regarding visual perception, how we interpret such incoming visual information.

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2
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1answer
16 views

Do people who experience heautoscopy become unable to see their reflected image in a mirror?

I understand that people who experience autoscopy can see their body image outside them without a mirror. I had read many years back in a paper that people who experience the inverse phenomenon called ...
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1answer
36 views

Why is the occipital lobe behind instead of in front?

These are regions of our brain: Our eyes are in front below our forehead, however, the visual area Occipital Lobe is behind. Are there any biological reasons for this? why shouldn't Occipital Lobe be ...
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Parallel target search and serial blank search

Wolfe (1991) reports an example of a search that seems to be parallel for target trials and serial for blank trials: Is anyone familiar with other examples of a dissociation between target-present ...
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1answer
94 views

Source for turning cone cell opponent process diagram into equations

There is a diagram on wikipedia that is part of the article on the opponent process. I assume practical equations have been developed, at least reasonable approximations, but they appear to be missing ...
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1answer
56 views

Equalize/balance brightness and saturation of different colors using RGB (across various monitors)

We want to present different colors to participants in an online experiment (in an HTML/CSS-based application, hence we'll use RGB values). More in specific, we ...
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20 views

Objectively defining the image parameters for facial detection, recognition, and identification in digital imagery

Axis communications have given guidelines on minimum operational requirements of a camera to allow a human observer to identify, recognise, and detect human subjects (https://www.axis.com/en-ca/...
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1answer
43 views

Why is deltaE not used as a measure of error?

I've recently read a few articles pertaining to visual memory. Most of them (e.g. https://doi.org/10.1167/9.10.7) use the continuous color recall task where they ask participants to recall the color ...
5
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1answer
215 views

Do cats exhibit the bouba/kiki effect?

I was fascinated when I first read Ramachandran's article about kiki bouba effect, and I was wondering if cats experience the same thing... As Ramachandran proved, our angular gyrus is responsible for ...
2
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1answer
36 views

Why does an image seem smaller or larger through a pinhole when viewing with human eye

I was chewing gum when I took the Trident gum wrapper and rolled it into an open cylinder with a diameter of about 1.5mm (give or take 0.15mm). When I look through the gum wrapper (I have to put it ...
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1answer
32 views

Can eye tracking be used as a form of biofeedback?

I'm an occasional meditator and I've noticed that conceptual thought often produces eye movements, and I'm curious if anyone has tried using eye movements as a form of biofeedback. The Muse headset ...
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Why does an image seem smaller through a pinhole when viewing with human eye

I was chewing gum when I took the Trident gum wrapper and rolled it into an open cylinder with a diameter of about 1.5mm (give or take 0.15mm). When I look through the gum wrapper (I have to put it ...
3
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0answers
23 views

How does number sense develop in blind people?

From what I understand about number sense and numerical cognition, the visual system is heavily involved in the approximate number system and the object tracking system, which are at the root of ...
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21 views

Retinotopic mapping to higher visual cortex

I know visual stimuli from retina presented in Cartesian coordinate is mapped to V1 as a form of polar coordinates. Wikipedia, Scholarpedia But I wonder whether this spatial representation in polar ...
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33 views

Accuracy of visual distance and size perception

Generally speaking it is known that human observers’ perceptions of distances in depth are generally inaccurate. I guess that the accuracy is sometimes a very large degree. To be more specific I am ...
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1answer
1k views

Are scintillating scotomas really caused by cortical spreading depression? If so, how is this known to be true?

I have just read about a visual effect called a scintillating scotoma. Many variations occur, but scintillating scotoma usually begins as a spot of flickering light near or in the center of the ...
4
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1answer
27 views

Multistable perception with three possibilities

I know that multistable perception refers to the phenomenon that occurs when we look at an ambiguous image like a Necker Cube or some sort of positive/negative space art, and we can’t perceive both ...
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28 views

Decussation of Cranial Nerves

Which cranial nerves decussate apart from the few nerve fibers of the optic nerve that do and how to easilly remember the cranial nerves that do? Here is a paper for the Trochlear Nerve But I have ...
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1answer
689 views

Proportion of cortex dedicated for vision and hearing

I have read in some websites that the percentage of the cortex devoted to processing visual information is from 30-66% with some claiming even 90%. And compared to that, only about 3% is dedicated to ...
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1answer
580 views

Distortion of faces presented serially in peripheral vision

I've kind of already answered this question for myself, but I can't resist sharing it anyway. Please feel welcome to add anything you can in another answer. Stare at the cross in the middle and try to ...
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2answers
2k views

Due to Gestalt Psychology, is the face an illusion?

Gestalt Psychology maintains that we perceive a whole from parts, and that we fill in missing gaps. The "whole" we perceive is more than the sum of parts we perceive - it also involves what our minds ...
4
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1answer
62 views

Visual Cortex percentage

Could somebody help please in providing some research papers or a resource book that states how much the visual cortex occupies of our cortex? I am trying to find some reliable source but I couldn't ...
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39 views

Relaxing your concepts in meditation

I am using the app Waking up from Sam Harris. A lot of his guided meditations tell you to perceive the world as the raw data of experience, instead of perceiving objects and concepts. To illustrate ...
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27 views

Is there a double dissociation between face and object processing?

We know of the condition called prosopagnosia in which the processing of faces is impaired. Is there a condition in which the processing of faces is intact and the processing of objects is impaired, ...
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1answer
263 views

Visual field testing: Choose between Yes/No, 2AFC, and 2IFC task?

As a newbie to psychophysics experiment, I have a small project to do visual field testing on healthy, adult, naive subjects. The experiment stimulus is a small sine grating (0.3 degree, 6 cycles/...
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6answers
45k views

Why would the brain flip the images perceived by your eyes?

The following is a common scientific statement, which you don't have to google long for to find: The eye views images upside-down in the manner of a camera lens, but our brains reinterpret this ...
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1answer
542 views

How does a person who wears prism glasses through which the world is perceived upside-down experience the transition back to normal?

If someone wears prism glasses that turn the visual field upside down (see this video), this person will eventually adapt and see the world in its normal orientation again. Now my question is, how ...
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Is there some cognitive test besides (visual) working memory in which some animals are superior to humans?

Assuming the research of Matsuzawa et al. (2007) (see also BBC video (2013)) isn't misleading, are there any other cognitive areas where chimpanzees (or other primates) have been observed to surpass ...
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1answer
66 views

Is the visual cortex of a newborn baby immediately capable of object detection or is this skill learned over time, and if so, how?

Is the visual cortex of newborn babies right off the bat capable of making sense of raw visual data, for instance, converting the constant stream of raw RGB images perceived by the eyes into a ...
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1answer
152 views

Is there a foveal explanation for the duck-rabbit illusion?

Myself when I look at the duck-rabbit image, I see a duck if focus on the left (i.e. the beak) or a rabbit if I focus on the right (the nose). Is this how it works for most people, i.e. is the foveal ...
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2answers
408 views

Why can we not see around our point of focus of our eyes?

Why do we have to strictly focus on something to really see what it looks like? Is everything else around blurred, or is our brain trained only to see in the center of the image projected on the ...
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1answer
77 views

Is the Thatcher Face Illusion only limited to face recognition?

The so called Thatcher-Illusion has been documented not only on humans but also in some monkeys. However I can't find literature clearing out if this effect only applies to face-recognition. What ...
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3answers
1k views

What is the “static” in human vision called?

Sort of like a cheap digital Camera, the human eye has certain feedback that's perceived but doesn't actually exist in the real world; a little layer of Static that's especially noticeable in pitch ...
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1answer
33 views

How are ocular dominance columns monocular despite binocular complex cells?

Orientation columns in the primary visual cortex are known to have (mostly) simple cells in layers 4 and 6, and (mostly) complex cells in layers 2,3 and 5. Orientation columns spanning an entire range ...
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1answer
42 views

Is there any evidence for or against the existence of neurons that encode surface slant in vision?

In the way orientation columns display selectivity for various edge orientations projected on the retina which is then repeated at various angles in a localised region of the cortex. I am wondering ...
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55 views

Could one use priming (from realistic images to drawings thereof) to help teach the conventions of line drawing?

Line drawing is a very stylised form of art. There are no lines in nature, and artists have to learn the conventions to be used when drawing in line. I am interested in whether one could help them ...
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1answer
154 views

Unilateral vision in split brain subjects

I am just beginning to learn psychology and came across concept of split brain. I was wondering if a person has only left eye working and has their corpus callosum cut, would they be effectively blind ...
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57 views

What is it about Ken Reid's style of drawing lumps on surfaces [shown here] that makes our visual system so easily interpret it?

Ken Reid was an artist who drew for the Beano and other comics, and was known for strips such as Frankie Stein and Queen of the Seas. And for The Nervs, about the little men who run our brains, but ...
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1answer
32 views

Differences in reaction time on visual tasks with and without binocular disparity ques?

Have there been any studies done that test the reaction time to vision processing tasks with and without the benefit of binocular disparities? I have been wondering how much depth information (such as ...
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1answer
61 views

Does transparency have its own visual channel?

Referring to (for example) Visual Thinking for Design, the book discusses various low-level processing channels in the brain. Colour and orientation are two examples. I wonder if transparency is ...
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1answer
567 views

Is there an effect of visual expertise on eye movements when examining an image?

In the following linked image, you can see the eye movement traces of a subject examining a bust of Nefertiti (I came across this image while reading the following blog). When I was in grade school, ...
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1answer
35 views

How do I interpret an effect of electrode position in ERP research?

The example I have in my research is that both conditions show greater amplitude and latency in the parietal electrode sites than in the occipital ones. I'm not sure how meaningful this is for my ...
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1answer
27 views

Fit a psychometric function when the maximum is not 100% (not because of lapse)

I found that currently the form of psychometric function assumes that the proportion correct lies between 0.5-1 given the range of stimulus level, but how to fit a psychometric function when the ...
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2answers
395 views

If the optic nerve transmits to both hemispheres, how do split-brain experiments work?

From what I understand, the optic nerve of each eye transmits information to both hemispheres of the brain. This is unlike other sensory and motor information, where (for example) the right hand is ...
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66 views

Is the perception of drawings an acquired skill?

Most descriptions of visual perception explain how our brains interpret incoming visual stimuli (via feature detection, monocular depth cues, etc.). They then assume that the same process works for ...
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3answers
1k views

Why is sensory substitution not that successful?

By successful, I mean made it out to the large world market or being massively funded. After looking online it seems that the most relevant research is the one done by Bach-y-Rita about the seeing ...
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1answer
133 views

Finding largest level of imperceptible noise in an image

Suppose that we want to find the "largest level" of a random noise that can safely be added to an image such that the resultant noisy image cannot be distinguishable from the original noise-free image....
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1answer
125 views

Why do views make you happy?

Why does having a nice view from your window make you happy? (As in people ask for a hotel room with a nice view). Could this be replicated by simply having a large TV screen showing a view? What ...
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1answer
91 views

Why do we see shadows in the following black-and-white optical illusion?

How does neuroscience explain the following optical illusion? Look at tiles. You will see spots of shadow near all corners. The shadow will be missing from some corners very near the center of your ...
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1answer
110 views

Human vision detection of faint blinking or moving point of light, guidelines for sensitivity versus frequency

This question is in the neurology/neuroscience rather than the psychology aspect of this site. I'd like to check the limits of visibility of a (presumably green) LED at large (kilometer) distance, ...
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3answers
8k views

Why is it easier to see black text on a white background?

I'm wondering why it's easier to see black text on a white background than it is to see white text on a black background. I say that it's harder based on life experience (Hate webpages with black ...

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