PSY374H5 Lecture Notes - Lecture 6: Positron, Hemoglobin, Magnetic Resonance Imaging
Document Summary
Background: higher cognitive functions related to cerebral cortex (layer covering the surface of the hemispheres) Different cortical regions are coarsely associated with different cognitive functions (vision, motor planning, etc. ) Are there specific brain regions associated with language abilities? (language is not modality specific) Starting point: is language associated with a specific hemisphere? (the lateralization of language ability) traditional methods used to answer this question: (1) dichotic listening task (2) wada test (3) tachistoscopic methods (4) commissurotomy patients. Comparatively easy task to compare that gives robust results. Stimulating each ear differently or the same. Have to say back what they hear. Wada test: inject barbiturate into carotid artery, on one side then the other. Common to be studied on patients with severe epilepsy before they go in for surgery. Most right-handed people show left-hemisphere dominance for language, left-handers show less lateralization. Used to determine the position of speech in the brain before operating.
