Naked Science Forum
Life Sciences => Physiology & Medicine => Topic started by: dgt20 on 16/03/2018 10:43:19
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How do the optic nerve and occipital lobe relate to the reaction time of a human?
Also, are there any type of physiological differences between photoreceptors (rods and cones) that could result in a different reaction time?
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Do you mean the rate of information transmission along the nerve and then the rate of processing through the visual cortex?
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Do you mean the rate of information transmission along the nerve and then the rate of processing through the visual cortex?
Yes, how does the two relate to the time of human reaction?
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How does reaction time depend on photoreceptors?
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Human reaction times to simple visual stimuli take around 250-300ms.
- If the stimulus is faint or has a low contrast ratio, it takes longer to recognise
- If the stimulus is complex, it takes longer to recognise
- Response times can improve with practice, moving into the unconscious mind
- Human visual processing is very complex, with signals passing through many layers of neuronal processing in the brain - and even a considerable amount of processing in the retina itself.
- Auditory processing is much simpler, with response times of around 100ms
- It is part of the mystery of consciousness that we perceive sight and sound to be happening simultaneously, even though they have quite different processing times
- The human brain unconsciously takes the speed of sound into account - if the sound and the picture are "out of sync", your brain is somewhat tolerant of the image happening before the sound; when the sound happens even slightly before the picture, it feels "wrong".
See: https://en.wikipedia.org/wiki/P300_(neuroscience)