Brain and Language PDF

Support for Lateralization: Split-brain patients • Split-brain surgery: the patient’s corpus callosum is cut. • The corpus callosum allows information to go between hemispheres, but it also contributes to the spread of seizure impulses from one side of the brain to the other in people with epilepsy....

Support for Lateralization: Split-brain patients • Split-brain surgery: the patient’s corpus callosum is cut. • The corpus callosum allows information to go between hemispheres, but it also contributes to the spread of seizure impulses from one side of the brain to the other in people with epilepsy. • Once the corpus callosum is cut, seizures will not spread from one hemisphere to the other, making them less severe. From: http://www.webmd.com/epilepsy/guide/corpuscallosotomy 18 Support for Lateralization: Split-brain patients • Joe is a split-brain patient, meaning his corpus callosum was surgically severed. • http://youtu.be/ZMLzP1VCANo • Why does Joe draw a saw when he says that he sees a hammer? – Hammer is on right side; this info is passed to left (i.e. language) hemisphere à Joe can say “hammer” – Saw is on left side; this info is passed to right (i.e. non-language) hemisphere à Joe cannot say “saw” (or even think consciously about the word “saw”), but he can draw it with left hand, which is controlled by right hemisphere 19 Getting More Specific: Localization within the left hemisphere • At least two centers of language processing: 20 Localization within the LH • Much of our early knowledge about these areas came from aphasiology: • Aphasia: a disruption in language abilities (production and/or comprehension) due to brain injury. 21 Localization within the LH: Tan’s Brain • Couldn’t produce language. • His utterances were limited to a single syllable, “tan”. “Tan’s brain” 22