Practice question · Put in order
Order the causal chain explaining why a split-brain patient cannot name a word shown in the left visual field.
- Because speech is produced in the left hemisphere, the patient cannot say the word.
- Yet the left hand, controlled by the right hemisphere, can point to the matching object.
- With the corpus callosum cut, the right hemisphere cannot pass it to the left.
- A word is flashed only in the patient's left visual field.
- The image is routed to the right hemisphere only.
Hints
- Trace the image from visual field to hemisphere, then to the blocked crossing.
- The naming failure and the successful left-hand pointing are two SIDES of the same disconnection.
Show the answer
- A word is flashed only in the patient's left visual field.
- The image is routed to the right hemisphere only.
- With the corpus callosum cut, the right hemisphere cannot pass it to the left.
- Because speech is produced in the left hemisphere, the patient cannot say the word.
- Yet the left hand, controlled by the right hemisphere, can point to the matching object.
Why
Left visual field -> right hemisphere -> blocked at the severed callosum -> left (speech) hemisphere never gets it, so no naming; but the right hemisphere still drives the left hand to point. Naming fails and pointing succeeds for the same reason: the disconnection.
Practise Hemispheric Specialization
The app has 6 more questions on this lesson, and keeps your place in the course. Psychology I is free to start.
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