AAMC Practice Psych #48

[Okazaki Frag Grenade]

Can someone help me understand why this answer is correct?

Question states: In a study of split-brain patients, patients are presented with a target color only in the left side of their visual field. They then need to identify the color. This procedure would specifically allow researchers to investigate whether: (see picture; CP stands for Categorical Perception)

I get that the brain uses the left side for language comprehension/production/etc, but this question seems like it could be both A and B. If it is necessary to cross hemispheres to produce an answer, then the corpus callosum would be integral in that, and since this is resected in split brain patients, then that would show its importance. I'm just wondering why A is more correct than B. Thanks!

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[chemist16]

Might be semantics, as "processing" is used in a very narrow and specific context in neuroscience. The corpus callosum does not play a role in the actual processing of the information - that happens in the neural circuits in the language areas.

 

[desertrat12]

Might be semantics, as "processing" is used in a very narrow and specific context in neuroscience. The corpus callosum does not play a role in the actual processing of the information - that happens in the neural circuits in the language areas.

I agree. It also helped me to 1st remember that things on our left visual field will be sent to the right hemisphere of our brain, but if I close my left eye and only take in things on the left visual field from my right eye (so skipping the corpus collosum) I can still process the color the same in that I can still see what color it is. With no corpus collosum it would be the same, the color would still be there, the difference would be that you wouldn't have a way to then take that color and go get a name for it.

 

[amy_k]

Agreed, definitely semantics of "processing" versus "perception"... my first thought to this question was that color processing is usually referred to as very early on in the retina via receptor cells and subsequent transmission to the primary visual cortex area (there are 4 or 5 studied areas of the visual cortex, V1 would receive initial sensory information about color from the retina and this is passed to the secondary visual cortex and beyond), whereas perception is the process that occurs via the corpus callosum in the later visual cortex areas (V4 especially is linked to contralateral signals). I.e. they are wanting to contrast that corpus callosum plays a significant role in color perception, a later stage in the brain (rather than processing which is a primary process). After looking through a few real life split brain studies online, they do refer to color processing as retinal sensory information and the perception as the process that occurs in the brain, but the distinction between the two seems a little too specific for MCAT.