In split-brain patients, presenting a visual stimulus to the left visual field would most likely be reported by the patient as:

• A. Unable to name the object but able to draw it with the left hand
• B. Able to name the object aloud
• C. Able to point to the object with the right hand
• D. Able to describe the object verbally

Answer: (A)

Left visual field information is processed by the right hemisphere. In split-brain patients, the severed connection to the left hemisphere prevents language centers there from accessing what the right hemisphere perceives. The right hemisphere, though, is adept at visuospatial tasks and controls the left hand, so the patient can express the seen object by drawing it with the left hand but cannot name it aloud. If the stimulus were shown in the right visual field, the left hemisphere would process it and the person could typically name it verbally.