Home › AP Psychology › Psychology › Biopsychology › A split-brain patient cannot name a picture show…
A split-brain patient cannot name a picture shown in the left visual field, yet can draw it with the left hand. This is because:
AThe left hemisphere processes both hands but not speech
BThe right hemisphere sees it and controls the left hand
CThe corpus callosum has grown thicker after the surgery
DVision from each eye reaches only the nearer hemisphere
Answer & Solution
Correct answer: B. The right hemisphere sees it and controls the left hand
1. In severe epilepsy the corpus callosum, a band of roughly 200 million axons, may be severed to stop seizures spreading between hemispheres.
2. Information from the left visual field is available only to the largely nonverbal right hemisphere, so the patient cannot name what was shown.
3. Because the brain works by contralateral control, that same right hemisphere controls the left hand, which can therefore recreate the picture.
4. Once the more verbal left hemisphere sees the drawing the hand has produced, the patient can name it.
5. Option C reverses the surgery, which cuts rather than thickens the connection between the hemispheres.
_Source: OpenStax Psychology (1st ed., CC BY 4.0), Ch 3 "Biopsychology", §3.4 The Brain and Spinal Cord_
Related questions
The chapter describes hyperthyroidism as producing which set of symptoms?A researcher needs to track brain activity with millisecond accuracy but does not need to After surgery removed his hippocampus, the patient known as H.M. could still learn new skiWhat caution does the chapter attach to the famous case of Phineas Gage?In the adoption study reported in the chapter, the highest rate of schizophrenia was foundThe idea that a child of a professional athlete is exposed early to that sport, and that tThe epigenetic perspective differs from the range of reaction view because in epigenetics:Why is the sickle-cell allele described as adaptive in regions where malaria is common?