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 ...
- 7,735
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 ...
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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 ...
- 2,633
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,...
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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), ...
- 7,735
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 ...
- 7,735
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 ...
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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 ...
- 20.7k
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 ...
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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 ...
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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
...
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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 ...
- 20.7k
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 ...
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4
votes
How do mammals estimate the speed of moving objects?
@AliceD gave a great answer on the bottom up pathway. Let me add some top-down processing bits into the picture, since that's what you are asking.
First of all, at a perceptual level, motion ...
- 850
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) ...
- 3,522
4
votes
Accepted
Do we perceive contrast colour patterns easily because of adaptation?
Short answer
Contrast is hardwired in the visual system and can be explained by retinal and brain connectivities without the need for adaptive processes. My answer pertains to adaptation at the ...
- 20.7k
4
votes
How to use a QUEST staircase in 2-AFC?
Start here: Adaptive Psychophysical Procedures (Treutwein, 1995) [PDF]
If you want to get fancy, I suggest a more contemporary approach for the staircase called accelerated stochastic approximation. ...
- 628
4
votes
How to use a QUEST staircase in 2-AFC?
There are numerous studies that reveal contradictory data about face-to-face in autism. Continues the research paradigm that contrasts faces and objects.
https://www.ncbi.nlm.nih.gov/pmc/articles/...
- 1,069
4
votes
Accepted
Learning In Retina
It is not immutable. There are many studies on retinal plasticity, for example using laser coagulation and showing that after selective lesions new connections can be formed even in the adult retina, ...
- 156
4
votes
The interactions between hallucinations and reality in people with schizophrenia
Unfortunately hallucinations of visual type seldom occur with schizophrenia. When visual hallucinations occur in schizophrenia or more frequently (but still uncommon) in other disorders they are ...
- 401
4
votes
Accepted
The interactions between hallucinations and reality in people with schizophrenia
Short answer
Visual hallucinations in psychotic disorders like schizophrenia are typically not simple transformations of an inanimate lifeless object into another state. They are not a car turning ...
- 20.7k
4
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 ...
- 202
3
votes
Accepted
What is the difference between apparent motion and apparent movement?
There is no difference between the two; illusionary movement and motion are interchangeable terms. For example, a definition of apparent motion is (Oxford Index):
A sensation of movement in the ...
- 20.7k
3
votes
Is the Rubin Vase illusion an example of inattentional blindness?
Short answer
The Rubin Vase is a visual illusion, which can be traced down to the way the visual system analyzes visual scenes in terms of objects and background. Inattentional blindness is not an ...
- 20.7k
3
votes
What does the visual feed from the retina look like before it is processed by the visual cortex?
There is a LOT more to "your eye doesn't 'see' images, your brain reconstructs them" then what is shown in that picture. After the image is flipped and distorted, contrast information at various ...
- 407
3
votes
How is the focal point determined when looking into a clear sky?
Accommodation is the process where the lens in the eye changes shape to focus on an object. The eyes have a default accommodation distance, called the resting point of accommodation (RPA). The RPA is ...
- 20.7k
3
votes
Accepted
How do mammals estimate the speed of moving objects?
Two areas in the visual cortex are associated with the perception of velocity, namely:
The primary visual cortex (V1) and
The middle temporal area (MT or V5).
Both V1 and MT contain neurons that ...
- 20.7k
3
votes
Can color blindness be treated with image filtering technology?
Short answer
Lost spectral sensitivity in bichromats or monochromats cannot be made up for by technology. The only thing technology can do is to process the visual image and shift its spectral content ...
- 20.7k
3
votes
Accepted
Is habituation responsible for inaccurate airport security screenings?
The main reason for these failures is mental fatigue and lost of concentration, in conjuction with the weak target signals.
Vigilance decrement is defined as "deterioration in the ability to
...
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