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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How to train our brain to see everything in slow motion?

People who had near death experience often found that they were able to see everything in slow motion and capture every details in their surrounding at that particular period. Because the brain ...
6
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1answer
116 views

How come we see a line when there isn't one in this picture?

I got this picture I generated myself and I don't understand how come we can see two diagonal lines when, I think, there is no actual lines. Zooming in: Center: Just another 2px wide square… ...
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37 views

Why do I see those static pictures as they are moving [duplicate]

Have a look at the following static pictures: There are more of them here. On the same website this PDF describes findings.However I could not find any explanation why this phenomenon happening. ...
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1answer
62 views

Is consciousness a sub product of the brain or is there a duality? [duplicate]

I am trying to understand what consciousness is, based on my basic knowledge of our senses, artificial intelligence (computer vision, specifically) and some philosophy. Here's my reasoning: As far as ...
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116 views

How are humans able to read scrambled text/characters (e.g., CAPTCHA)?

So I'm doing a research on developing a new text-based CAPTCHA system. I've devised a scheme where characters in a text are broken/split individually and randomly, making it difficult for OCR machines ...
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1answer
50 views

Where can I find stimuli for steady-state visually-evoked potentials?

I am a student working on a project which deals with Steady State Visually-Evoked Potentials (SSVEP) Stimuator. Does anybody know where can I find stimuli (checkerboard or single graphic) as a video ...
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1answer
72 views

How does the brain break down visual information for processing? What “channels” is visual input broken into?

Some time ago I remember reading about how the human brain breaks down visual information into a number of individual "channels". For example, one channel might focus on edges and lines, another ...
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2answers
126 views

Are the center surround receptive fields learnt or inherited?

I know that neurons higher in visual pathways can learn their receptive fields after birth, but what about the connections between bipolar cells and Amacarine cells which form center/surround on/off ...
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0answers
24 views

Is there a hierarchy of gestalt visual stimuli processing?

Let's say that we have a set of shapes. They can be grouped according to the different Gestalt laws of grouping. However, different Gestalt principles will divide the set into different groups, e.g. ...
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71 views

Optical illusions : human universal vs environmental influences [closed]

It's well known today that the susceptibility to optical illusions are influenced by the environment: multiple studies with the Müller-Lyer illusion conducted in Zambia proved this environmental ...
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2answers
122 views

How does this illusion - that I just inadvertently created - work?

As I was working on a basic chess application for Android, I loaded some chess clip art into my imageviews. Then this happened. Look closely at the top two rows. At first I was startled. My ...
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76 views

Does the retina encode visual information like a Bitmap or an SVG?

I heard recently that a scientist has developed a retina prosthesis. So I think this is a question that has an answer. Does the retina encode information like a Bitmap image or an SVG image? (A ...
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99 views

Is there a difference between visual short term memory and visual working memory?

As far as I can tell the two terms are used interchangeably. Do these two separate terms exist for historical reasons, or is there a distinction I'm missing?
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1answer
73 views

Visual acuity and offset stimuli

I'm currently setting up and experiment that utilises a visual search task that contains a circular array of target letters and a distractor that falls outside the circle. Obviously the further away ...
6
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2answers
70 views

Do the colour blind have a distinct visual cortex structure?

Studying the structure of the visual cortex, it seems there are many neural structures specifically dedicated to detecting and interpreting colour. For example, parvocellular cells are particularly ...
6
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1answer
70 views

Relationship between oculometry/pupillometry and disorders of consciousness

I recently got to wondering whether certain eye movements or pupillary responses were correlated with disorders of consciousness (coma, VS, MCS, or even locked-in syndrome). I know that the pupillary ...
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1answer
75 views

What is the meaning of “little efferent input” to retina?

Gollisch & Meister (2010) state that "the retina receives little efferent input from the brain" (p. 157). Could anyone describe what exactly this "little efferent input" (where it originates, ...
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61 views

The accuracy & malleability of memory for color

How accurate is colour memory for the standard person? It would seem most people are quite good at remembering the colour of objects by visualising the object. But in some cases peoples visualisation ...
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1answer
80 views

Effective sampling rate in human visual system

The [stroboscopic effect][1] is often explained as one of the problems of sampling. If sample rate is too low, you might have the impression of the signal frequency being low or even reverse. There ...
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1answer
1k views

How do the blind dream?

Lately, a friend of mine has been telling me that he's been having recurring dreams involving a certain rabbi, who died around a hundred years ago. Since there's been some controversy surrounding the ...
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98 views

Has there been a neuroscientific explanation of the color phi phenomenon?

The color phi phenomenon is a perceptual illusion in the visual domain which was demonstrated in an experiment by Kolers and von Grunau (1976). The experiment is as follows. A sequence of coloured ...
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54 views

Is there a difference between the time/effort it takes for the blind and the sighted to learn to read Braille?

The visually deprived brain undergoes extensive remodeling due to cross-modal plasticity. This leads to increased areas of the cortex being available for other purposes such as tactile processing. Now ...
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1answer
49 views

A subtle test for color-blindness

Is there a test method of proving a person being color-blind, without letting the test subject know, that he/she is being tested? E.g. showing the person cards with colored dots like depicted here is ...
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1answer
63 views

Does the brain stop processing data when the eyes move?

I was reading this question and remember back to the 70s when our local newspaper changed formats. In an article about why they made the changes that they did, one of the points they mentioned was ...
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1answer
28 views

What is the relationship between neurotransmitter release and resting potential in retinal bipolar cells?

Retinal bipolar cells are known to have resting potentials from which they can become more or less polarized. What I'm wondering is whether a bipolar cell's neurotransmitter-release rate is zero when ...
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1answer
91 views

Are some facial features more important than others in human facial recognition?

I'm often surprised by the human ability to correctly identify other individuals despite significant modifications due to ageing, hairstyle, injury etc. But, sometimes the addition of a beard and a ...
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1answer
45 views

Pupillometry: how long needs the pupil to respond towards an cognitive stimuli?

I would like to know if somebody could give me some literatur advice about the latency response of the pupil after a cognitive stimuli. I know that the light reflex response is quiet fast compared to ...
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1answer
48 views

Number of presynaptic inputs per cell in primary visual cortex

I have been digging in the literature lately, but I haven't found a nice answer with clear cut numbers (avg +- std) to this question: How many presynaptic inputs receives a pyramidal cell in primary ...
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64 views

What functions does the brain perform to recognize a familiar object unconsciously?

Let's say a person's brain experiences how a vehicle/object looks for the very 1st time. It would require lot of attention/focus/processing to analyse the object, extract features and train its neural ...
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2answers
250 views

What's the explanation of this optical illusion where many coloured arcs radiate from a central point?

I saw the image below on facebook. At first, I thought it's a GIF animation since it doesn't appear static but it turned out to be a static JPEG image and the apparent motion is caused by the brain. ...
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43 views

What is the source for the W3C's Contrast Ratio formula?

The Word Wide Web Consortium (W3C) has a formula for the contrast ratio of any two arbitrary colors, which they use to set minimum standards for text legibility: ...
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2answers
172 views

What is the minimum angle off horizontal before a line visually appears inclined at first glance?

Here is a straight line, which visually looks like a straight line: At first look (lets say minimum 2–3 sec.) the line below looks straight, but after some time you can see that it is actually an ...
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0answers
67 views

What would happen if you saw no form of light for a year?

It's proven that low levels of dopamine result in depression, anxiety, etc. And low levels of dopamine just means a lack of production or intake by the dopaminergic receptors. If the lack of happiness ...
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31 views

Grating orientation & frequency which induces highest gamma

I am doing some research on perception and gamma activity in V1 area. To check some of my results I need to find an experimental result, from which I would know which orientations and frequencies of ...
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1answer
29 views

What study showed that humans can successfully detect objects within images once they are able to recognize those objects?

A professor in an online lecture I was watching referenced a study which he said showed that our ability as humans to detect objects within scenes (especially complex scenes) was very much connected ...
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2answers
42 views

Do we have a predisposition to view visual stimuli in a clockwise pattern?

I understand that we typically view the center of the image first and then are likely to move on a horizontal axis, but is there evidence that we tend to follow a clockwise path when viewing more ...
5
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1answer
120 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 ...
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1answer
41 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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2answers
103 views

How fast is the visual system?

I've heard that the visual system is one of our slowest sensory systems. How fast is the visual system, and how does it compare to other sensory systems (auditory, mechanosensory, pain, etc.)? For ...
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1answer
70 views

Binocular rivalry in animals?

Are there any experiments on binocular rivalry in animals? (In humans, brain responses to Rubin's vase are for example well studied.)
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2answers
149 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
846 views

How does the brain read rotated text?

Suppose a human ran across a letter written at a 45 degree angle. How does the brain read this text? Most people don't often see text written at an angle, so it seems safe to assume that the brain ...
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1answer
50 views

3D Glasses Aftereffect

I am wearing a pair a 3D glasses. The left lens is red and the right lens is cyan. However, when I take them off, my left eye sees in cyan and my right eye sees in red, the complete opposite of the ...
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1answer
55 views

What is the metabolic load of the visual system?

The brain consumes energy at eight times the rate that would be predicted from mass alone (20% of total organismic load). How much of this is drawn from the visual system? How does the metabolic load ...
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62 views

Evidence for a 2-component framework of visual attention distribution

As part of my bachelor thesis on eyetracking-based gaze guidance, I've done quite a bit of reading (again) on visual attention and visual attention distribution. What caught my attention (haha) ...
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85 views

Progress on Arnheim's perceptual forces in vision

In the second edition of Rudolf Arnheim's Art and Visual Perception: A Psychology of the Creative Eye, published in 1974, the opening chapter on "balance" begins with a discussion of "perceptual ...
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1answer
59 views

How do hallucinations appear through reversing goggles?

If one is experiencing elaborated visual hallucinations, what will happen when one puts on reversing goggles? Will hallucinations change their orientations as well? Links to relevant papers will be ...
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2answers
105 views

What is the difference between spike-triggered averaging and reverse correlation?

I'm interested in the difference between spike-triggered averaging and reverse correlation. In some papers (i.e., Schwartz, Odelia, et al) I see the term 'Spike Triggered Averaging'. In others, (ie ...
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2answers
298 views

Does perception have a “frame rate”?

Are the objects of visual perception processes divisible into individual, still frames, like video is? If so: Are the perceptions from different senses synced to the same frequency? Are these ...
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2answers
106 views

Sensitivity of human eye to luminance

I heard once that the human eye has a logarithmic scale for luminance, e.g. to "feel" that a surface is three times as luminous compared to another, the former emits a light 8 times more powerful than ...