Fill in the Diagram

Question 1

1) Split brain patients: what is damaged, what can they say, what would they pick up with what hand, etc.

Answer 1

Damage: the corpus callosum is damaged or cut. General: patients are conscious of left hemisphere activity. Only the left hemisphere can verbalize. The right hemisphere can only demonstrate (pointing, drawing). Patients are unconscious of what their right hemisphere (and thus left hand & left visual field) is doing. Remember: right visual & right hand = left hemisphere. Left visual and left hand = left hemisphere. Right visual field = left hemisphere = can consciously verbalize it and point at it with right hand, but not left hand. Left visual field = right hemisphere = can’t verbalize and not conscious of it, but left hand can pick objects out or draw them. Patients who grab a pencil with their left hand (RH) and an orange with their right hand (LH) will claim they are holding oranges in both hands (since they have conscious access only to their left hemisphere). Cross cuing = one patient would shake head and frown after he made an incorrect answer, then he’d change the answer.

Question 2

Sequence for repeating a spoken word:

Answer 2

1) Auditory analysis (primary audio cortex), transmits to Wernicke’s area. 2) Wernicke’s analyzes sound to determine what word was said. 3) Information is transmitted from Wernicke’s to Broca’s area via the arcuate fasciculus. 4) Broca’s area forms motor plan to repeat word and sends that information to the motor cortex.

Question 3

Sequence for repeating a written word:

Answer 3

1) Visual cortex analyzes image and transmits that information to angular gyrus. 2) Angular gyrus decodes the information to recognize the word and associate this visual form with the spoken form in Wernicke’s area. 3) Information about word is transmitted to Broca’s area via arcuate fasciculus. 4) Broca’s area forms motor plan to repeat word and sends that information to the motor cortex.

Question 4

What are the functions of the different language areas of the brain? What happens if they are damaged?

Answer 4

Broca’s area – Function = language production. Damage = expressive aphasia: (difficulty speaking), particularly GRAMMAR problems, but can still comprehend language. Wernicke’s area – Function = language comprehension. Damage = receptive aphasia: cannot access semantic meaning of words, so problems with comprehension. Their speech sounds normal, but has no meaning. Arcuate Fasciculus – Function = connects Broca’s and Wernicke’s areas. Damage = conduction aphasia: comprehension and speech are normal, but unable to repeat words. Primary visual cortex – Function = analyzes visual input and transmits words to Wernicke’s area. Damage = alexia (can’t read) and agraphia (can’t write). Primary motor cortex – Function = motor formulation of speech. Damage = speech problems. Primary audio cortex: Function = analyzes audio input and transmits words to Wernicke’s area. Damage = pure word deafness (doesn’t understand speech). But ability to speak is intact, and can recognize non-language sounds. Angular gyrus - Function = gateway from visual cortex to Wernicke’s area (written words). Damage = alexia (inability to read) and agraphia (inability to write).