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
96 views

What is the cause of differences that are too small to see?

Consider two identical pieces of paper. Scenario 1: On both something is drawn in black ink. If the difference between the areas covered in black ink is sufficiently small, I cannot see the ...
2
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1answer
93 views

Is there a waterfall visual after-effect with discrete inputs?

If you watch a waterfall for several seconds and then suddenly change your gaze to a fixed object it appears to briefly move upward. But if instead you're looking at a scrolling LED marquee sign, ...
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1answer
40 views

Are the receptive fields of bipolar and retinal ganglion cells directly stimulated by light?

I know this is a basic question, but I can't find the answer anywhere. How can a cell that is not photoreceptive (eg LGN and retinal gangion cells) have a receptive field that is stimulated by "light" ...
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0answers
87 views

Use of the visual cortex in mathematical thinking?

In modern computers (and programming) one makes alienated use of the high powers of graphical processing units (GPU) for non-graphics-related tasks, enhancing drastically the power of the general ...
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0answers
48 views

How bright must a light bulb to be noticed in a room?

If one has say an 800 lumen bulb, how many lux are necessary in order for a human to detect when it's suddenly turned on in a room with brightness levels of 30 Lux 50 Lux 100 Lux 1.-How many Lux ...
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0answers
102 views

Random-dot kinematograms implementation in javascript/HTML

I am looking for a "random-dot kinematograms" implementation in javascript/HTML that I can use in web-based experiments. Something like this, where the user can specify the direction using a mouse or ...
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3answers
1k views

How to use a QUEST staircase in 2-AFC?

Firstly, I need to declare that I am not psychologyst, however I am currently working on visual recognition research. To be precise, I working on face recognition deficits in Autism Spectrum Disorder. ...
8
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1answer
875 views

What explains the characteristics of the receptive fields of simple cells in V1?

Here is a YouTube video of a Hubel & Wiesel experiment from 1965 in the visual cortex. The video shows the experimenters outlining the receptive field of a simple cell in the first part of the ...
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1answer
95 views

Is habituation responsible for inaccurate airport security screenings?

The U.S. Transportation Security Administration has "red teams" who try to sneak dangerous items through airport security. The security personnel often fail up to 95% of these tests. Is this high ...
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1answer
272 views

What happens in my retina if I press on my eyeballs?

If I press my eyes I can "see" all kind of things: sparkling blue dots (which sometimes seem random and sometimes there seems to be a pattern in them), growing or diminishing rings of all kinds of ...
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0answers
38 views

What timing of visual emphasis paired with a spoken word provides the best cognition? [closed]

I am working on an animation in which there are three somewhat small font words (Environmental, Social, and Economic) together with three colored horizontal histogram bars on each side of the labels ...
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1answer
1k views

Can color blindness be treated with image filtering technology?

Using image color-filtering techniques we can simulate the way colorblind people see: The aim of this question is to know whether the opposite process could be possible, namely can a colorblind ...
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1answer
80 views

What is the neural adaptation underlying the habituation to reversed visual images? [closed]

When a person wears glasses that reverse the image upside-down, it is possible to adjust your vision in a matter of days. What are the suggestions behind the neurological process?
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1answer
20 views

Can we learn to adapt to image-reversal when being intermittently exposed to them?

I know that human vision can get accustomed to reverse vision when wearing reverse glasses for several days. But does it work when we see the reverse image just in certain moments throughout the day? ...
4
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1answer
679 views

Are we able to simulate pain through the brain?

I have like 0 experience or knowledge about brain signals and all that stuff but I'm curious about how much we know about the brain in terms of like tricking your brain that with simulation of pain. ...
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2answers
214 views

How is the biological error signal in predictive coding computed?

I am quite inspired by the results obtained by PredNet, which implements a predictive coding model using artificial neural networks. They compute the prediction error as a simple subtraction, and then ...
4
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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 ...
5
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1answer
263 views

What do you call sensations without stimuli?

Sometimes, when you close your eyes in the dark, you see what looks like sparks or flashes. Sometimes when you are tired, your vision seems to shift sideways and realign, like someone bumped into a ...
4
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1answer
205 views

What is the optimal contrast ratio for best readability?

I have asked the same question half a year ago on Graphic Design but received no useful answer. According to the W3C (and another question on this site), the contrast ratio between body text and text ...
5
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1answer
151 views

Do non-human primates exhibit the Kiki/Bouba effect?

After understanding that cats cannot experience the Kiki/Bouba effect, I wonder if smart non-human primates can experience it. There is evidence suggesting that Chimpanzees associate high pitch with ...
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3answers
489 views

Does the strength of the simultaneous contrast illusion vary with the length of time it is viewed?

I have done several searches without finding any papers addressing this question.. I'd like to know if there is any evidence to suggest that the strength of the simultaneous contrast illusion (or any ...
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0answers
39 views

Model of human estimation of correlation tasks

I am looking for a model (bayesian or not) on how people would estimate the correlation between two variables from a given scatter plot. Any one knows of such model?
4
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1answer
3k views

What is the difference between apparent motion and apparent movement?

A definition for apparent movement is: The perception of movement produced by stimuli that are stationary but are presented first at one position and then, at an appropriate time interval, presented ...
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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 ...
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1answer
5k views

Is the Rubin Vase illusion an example of inattentional blindness?

Generally, people looking at an example of a Rubin Vase see either the vase, or the faces. The brain seems to make a decision on which one is being viewed, but both cannot be focused-on at the same ...
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2answers
480 views

What does the visual feed from the retina look like before it is processed by the visual cortex?

I was recently at the ACM Symposium on Applied Perception, where I saw a keynote on visual attention. The speaker (Laurent Itti) showed an animation that blew my mind. It showed a video of fish ...
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2answers
101 views

How image orientation influences perception

Im a painter for many years. When I paint, I usually walk around and look at my painting for many hours. When painting session is long, it harder and harder to maintain a "fresh look". By fresh look; ...
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3answers
413 views

Is prior experience necessary to perceive the Kanizsa triangle illusion?

We know the Kanizsa Triangle. Kanizsa Triangle I was socialized in a "western" world, where I learned mathematics for about 13 years; I have designed products surrounding me using geometric forms ...
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1answer
847 views

How does the brain structure 3D visual data?

Adobe Illustrator has taken over five minutes (and counting) to render a vector 2D image rotated 18° in 3D on my computer. And yet, I and nearly anyone else can easily visualize the subject rotated ...
4
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1answer
423 views

What is the relationship between visual attention network and visual stream (Two-streams hypothesis)?

There are two visual attention networks proposed by Maurizio Corbetta and Gordon L. Shulman (2002). These are top-down and bottom-up attention networks. One system, which includes parts of the ...
2
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1answer
138 views

What is the relation of visual quality and distance from the central field of view?

I have read somewhere that Our visual perception degrades non-linearly with distance from the fovea. However, it was not referenced. I was wondering if there is a reference talking about this? ...
4
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2answers
163 views

Do we perceive contrast colour patterns easily because of adaptation?

I can understand that colours are just manipulation of our brain to light rays of different wavelength and energy. We perceive patterns better at higher contrast. Do we perceive patterns better at ...
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1answer
3k views

If the color black reflects no light, how are we able to see it?

If color as we perceive it is dependent on the wave lengths that are reflected by an object, with white reflecting all hues and black absorbing all, how do we detect a black object? I do understand ...
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1answer
156 views

Why can't hemineglect patients be trained to actively pay attention to their neglected side?

I'm still having a hard time understanding the symptoms of hemineglect, mainly because perception and attention has been two peas of a pod for most of my experiences. A Scholarpedia article states ...
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1answer
137 views

If I think of a checkerboard, is there a similar structure to see in my visual cortex?

When I´m imagining a checkerboard in my mind, can one find, with all kinds of fancy equipment, a corresponding figure in the area of my visual cortex? For example, the neurons firing in such a way as ...
4
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1answer
314 views

Does the human visual system implement (adaptive) histogram equalization?

The human visual system is very good at 'cancelling out' shadows and other lightning effects, and focusing on the contrast in images. A famous example of this is Adelson's checker shadow illusion: In ...
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1answer
50 views

Is there any evidence for a bias towards perceiving darker surfaces as 'figure' rather than 'ground'?

Given that surfaces which capture attention are more likely to be perceived as figures (or figures attract attention more than ground does?), is there a bias associated with the luminance of a surface?...
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0answers
14 views

Searching for literature on cognition of flyover animations

I'm rewriting a journal article on flyover animations: the virtual camera moves in a 3D map environment (e.g. a flyover of the Grand Canyon showing off the topography). The paper describes our user ...
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1answer
85 views

What is the maximum time difference to still associate an acoustic and visual event?

I am developing a game where the music needs to be synchronized to the actual game logic. That means that some objects in the game react to events in the music. Of course, the music will never be ...
11
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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 ...
3
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1answer
93 views

Is there visual focus during a saccade?

Has anyone succeeded in measuring where the focus is between saccades? Through some kind of nonintrusive brainscan perhaps? I would like to be able to draw with my thought :) (Something similar would ...
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0answers
22 views

Conscious versus Visual Representation Update

In their paper "A cortical network that marks the moment when conscious representations are updated" Stottinger et al claim that there is a network in the anterior insula, medial and inferior frontal ...
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1answer
85 views

Find the panda among snowmen!

I just saw this picture puzzle, and found it easily by doing a row-by-row scan, but it seems harder to find it just by looking around. I was thinking that the puzzle was intentionally designed to draw ...
2
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1answer
171 views

Do direct cortical pathways exist in the visual system, or do they all go via the thalamus?

Do visual cortical signals always go back and forth between the thalamus, or other subcortical structures, or can they travel directly from one region in the cortex to another?
2
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1answer
471 views

What is the difference between 'stereoscopic depth' and 'crossed/uncrossed disparity'?

What is the difference between stereoscopic depth and crossed/uncrossed disparity, and specifically in terms of their use in the methods to manipulate visual stimuli to investigate depth-perception?
3
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1answer
333 views

What is the location of the center-surround receptive fields of retinal ganglion cells?

I have read wikipedia article about receptive fields of visual system and it states the following: The receptive field is often identified as the region of the retina where the action of light ...
2
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1answer
59 views

Toolbox for modelling visual search performance

I'm looking for a toolbox to model visual search performance in a singleton search task based on line orientations (you need to find a line that is most different from all others in it's orientation). ...
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0answers
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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0answers
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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2answers
77 views

How do mammals estimate the speed of moving objects?

Has there been any research on how mammals predict the speed of moving objects? In particular, how do they integrate top-down information? For instance, do they have greater difficulty estimating the ...