11
votes
Accepted
What happens in your brain when you see a dinosaur in this stenographic image?
The source I have quoted below gives an example of the following stenographic image:-
Is this perception a particular trick that my eye performs or is it processing the visual data in an alternative ...
- 1,192
9
votes
Accepted
If I think of a checkerboard, is there a similar structure to see in my visual cortex?
Probably. What you mentioned in your question is called retinotopy. There is a mapping between locations on your retina and areas on your cortex. As you go further up the visual processing streams, ...
- 981
9
votes
Accepted
If the optic nerve transmits to both hemispheres, how do split-brain experiments work?
Some of those pop science articles might be simplifying a bit by saying the stimuli are provided to the left or right eyes. In fact, they are actually presented to the left or right visual field which ...
- 7,024
7
votes
Accepted
Why is it easier to see black text on a white background?
The short answer is that it is not necessarily easier to read black on white. Contrast is more important in lightness and colour, it just so happens that black and white is the highest contrast. So ...
- 1,186
7
votes
If the color black reflects no light, how are we able to see it?
Objects are visually perceived when they reflect light. A black object does not reflect any light. In other words, no photons are reflected to be detected by the photoreceptors in the retina. A black ...
- 20.5k
7
votes
Accepted
Do cats exhibit the bouba/kiki effect?
The bouba/kiki effect is the phenomenon that about 95% of subjects assign the name bouba to a blobby form, and the name kiki to a pointy shape (Fig. 1).
Fig. 1. Kiki and bouba, at least in 95% of the ...
- 20.5k
7
votes
Accepted
How to use a QUEST staircase in 2-AFC?
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 ...
- 2,648
6
votes
Accepted
How is saccadic movement managed in the brain?
The superior colliculus can be regarded as the center of saccadic eye movement. It contains a topographically organized representation of the visual space in its upper layers, and saccade-related ...
- 20.5k
6
votes
Is our attention attracted by bright lights?
In general, evidence suggests that we are attracted to contrast rather than brightness (luminance). For example, the onset of a bright light on a dark background is often used as an exogenous cue for ...
- 101
6
votes
Are we able to simulate pain through the brain?
Short Answer
It appears that stimulation of the thalamus would invoke feeling of pain:
Direct deep brain stimulation (DBS) in the VP thalamus from patients without pain typically evoked nonpainful,...
- 12.1k
6
votes
Accepted
When your two eyes disagree sharply
Binocular rivalry refers to a situation where you present different images to each eye (often in the context of an experiment, although you also point out some quick 'at home' ways to achieve this), ...
- 7,024
6
votes
Accepted
Why is the occipital lobe behind instead of in front?
From the retina, visual signals next travel through the lateral geniculate nucleus of the thalamus. This nucleus is quite centrally located, about as much in the middle of the brain as possible, and ...
- 7,024
6
votes
Accepted
What degree of control do we have on eye movements?
Short answer
We have a lot of control over our eye movements, including saccades. We can suppress saccades and make an anti-saccade instead. So can monkeys, our close cousins. Children have a lot more ...
- 20.5k
5
votes
In psychophysics, why are log luminance rather than absolute luminance values reported?
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 ...
- 20.5k
5
votes
To what extent do individuals vary in their ability to mentally visualise?
The phenomenon of not being able to visualise has recently been dubbed "aphantasia" by Adam Zeman at Exeter: see the university's press release Can’t count sheep? You could have aphantasia. They had a ...
5
votes
How is saccadic movement managed in the brain?
I agree with much of AliceD's well-cited answer, but here are a few extras.
What part of the brain is actively controlling saccadic movement?
It is not clear how you would choose just one ...
- 1,103
5
votes
Do direct cortical pathways exist in the visual system, or do they all go via the thalamus?
Short answer
Intracortical projections can be routed directly to other cortical areas (cortico-cortical projections), or via the thalamus (cortico-thalamo-cortical projections).
Background
...
- 20.5k
5
votes
How does the brain structure 3D visual data?
This question cannot be answered in the form in which you asked it both because of the limits of current neuroscientific theories and methodologies when it comes to determining the structures of ...
- 171
5
votes
What is the optimal contrast ratio for best readability?
Short answer
Higher contrast increases readability.
Background
In a series of papers under the umbrella "Psychophysics of Reading" (link is to first paper in the series of five) the authors ...
- 20.5k
5
votes
Accepted
What do you call sensations without stimuli?
Short answer
Visual hallucinations and, more specifically, phosphenes are the terms you are probably after.
Background
I'll basically provide a list of terminologies below, as your question seems to ...
- 20.5k
5
votes
Accepted
How does a person who wears prism glasses through which the world is perceived upside-down experience the transition back to normal?
Short answer
Based on the papers I've found I conclude that visual perceptions are not grossly altered after wearing prism glasses for extended periods. Instead, adaptation to prism glasses is mainly ...
- 20.5k
5
votes
Accepted
What happens in my retina if I press on my eyeballs?
Short answer
Pressure phosphenes are believed to be induced by sensory neurons in the retina downstream from the photoreceptors due to stretch-mediated activation.
Background
You are referring to ...
- 20.5k
5
votes
Accepted
Is V1 involved in visual imagery?
Short answer
V1 can be recruited for visual imagery, but it is not strictly needed for imagery to occur, and it is not sufficient in itself to allow for visual imagery.
Background
Visual imagery is a ...
- 20.5k
5
votes
Accepted
Is there a word that differentiate between image rotation and image translation?
I believe you are talking about recognition part that say if the image is transformed to be flipped one is able to righaway recognize the object, however if the transformation is say 90 degrees then ...
- 212
4
votes
Accepted
What is forward masking
Visual masking has quite a few variations, and the source you've linked is by far the worst explanation I've seen.
In forward masking an early stimuli takes hold over consciousness (resulting in top-...
- 1,115
4
votes
Why vision cannot count things instantly?
You probably mean instant quantity recognition
Counting requires a rather complex high-level process. For an animal to count you'd need:
Memory
Consciousness (to access and manipulate that memory)
...
- 1,115
4
votes
Accepted
Color and shape arriving together in visual system
It is something of an oversimplification to say that
there are separate visual pathways for both color and shape.
There are many cells, even in V1, which are selective for both colour and shape (...
- 1,103
4
votes
What is the source for the W3C's Contrast Ratio formula?
The W3C link provided by Mark in a comment on "Understanding WCAG 2.0" provides the source for the contrast ratio formula under the "Notes on formula" section.
The formula (L1/L2) ...
- 3,503
4
votes
Accepted
How long does it take to learn to cane travel?
Short answer
Generally, a few months of active, guided training.
Background
Based on an article from a guide cane instructor who is a cane traveler himself, I can answer the question as follows:
...
- 20.5k
Only top scored, non community-wiki answers of a minimum length are eligible