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P/S SB

Posted: Tue Aug 06, 2019 2:27 pm
by cr1123
Can you explain how one with a severed corpus callosum will say the word "ball" if the word is presented to the right visual field? My understanding is that with a severed corpus callosum information presented on one side will not be able to be perceived by the other side.

Re: P/S SB

Posted: Tue Aug 06, 2019 4:18 pm
by NS_Tutor_Mathias
The optic nerve crosses over at the optic chiasm, not through the corpus callosum. Even though it's not 100.00% precise, you can just think of the right visual field as landing in the left hemisphere and vice versa.

In more detail: The medial portion/fibers decussate (cross over) at the optic chiasm. Since the right visual field is made up of the lateral portion of the left eye and the medial portion of the right eye, and the lateral portion of the optic nerve does NOT decussate, ultimately both portions of the right visual field end up being processed in the left hemisphere. Additionally, language centers are (usually) localized to the left hemisphere - meaning this person is highly likely to produce the word 'ball'.