Prof. Greg Francis 1/2/12 PSY 200: Intro. to Cognitive Psychology 1 Purdue University Brain parts PSY 200 Greg Francis Lecture 02 What’s the deal with left and right brains? Purdue University The brain The source of cognition (consider transplant!) Weighs about 3 pounds Damage to some parts result in immediate death or disability Damage to other parts seems to have no effect! What brain parts are important to cognition? How do we discover the role of each brain part? Purdue University Fore-brain cortex Hind-brain brain stem) The brain Purdue University Hind-brain (brain stem) Limbic Lobe (sexual behavior, emotional behavior, memory) Cerebellum (muscle control, learning) Thalamus (sensory gateway, except smell) Hypothalamus (appetite, thirst, temperature, hormones) The brain Purdue University Fore-brain Cortex Similar to a thick, crumpled newspaper page Grooves (fissures or sulci) separate regions Purdue University Fore-brain Cortex Similar to a thick, crumpled newspaper page Grooves (fissures or sulci) separate regionsProf. Greg Francis 1/2/12 PSY 200: Intro. to Cognitive Psychology 2 Purdue University Fore-brain Cortex Similar to a thick, crumpled newspaper page Grooves (fissures or sulci) separate regions Purdue University Fore-brain Cortex Similar to a thick, crumpled newspaper page Grooves (fissures or sulci) separate regions Purdue University Contralateral processing Processing in the brain is done on the opposite side of your organs Control of your right arm is from the left side of your brain Information from your left field of view goes to the right side of your brain Purdue University Contralateral processing Neural fibers from the eye cross on way to cortex Purdue University Contralateral processing Brain hemispheres are connected by a mass of neural fibers called the corpus callosum Purdue University Cut corpus callosum Behavior changes very little Subtle effects http://www.youtube.com/watch?v=ZMLzP1VCANoProf. Greg Francis 1/2/12 PSY 200: Intro. to Cognitive Psychology 3 Purdue University Brain sides If “nut” flashes on left screen subject cannot name it subject can pick up nut with left hand If “nut” flashes on right side subject can name it subject cannot pick up nut with left hand until he says “nut” out loud 1981 Nobel Prize for Roger Sperry! Purdue University Brain sides Results led to further study and common belief that Left side: language, analytical, classification, Western rationalization Right side: art, music, recognition of faces and shapes, Eastern mysticism Vast oversimplification in a normal brain, both sides are involved in many tasks Results do support the idea that different parts of the brain are involved in different cognitive tasks (modularity hypothesis) Purdue University CogLab In the CogLab experiment Brain asymmetry You saw a pair of chimeric faces and were asked to choose which one looked younger Time Purdue University Chimeric faces The faces were made by taking a normal face and an artificially aged face Purdue University Chimeric faces Take opposite halves of the faces Purdue University Chimeric faces Put them together, and make the other face by flipping it Thus, both faces are mirror images, they contain the same informationProf. Greg Francis 1/2/12 PSY 200: Intro. to Cognitive Psychology 4 Purdue University CogLab If you stare at the middle of face, the information on the left goes to the right hemisphere which is supposed to be better able to deal with face information than the left hemisphere So the information on the left side of the face should dominate the face decision This face should look relatively young Purdue University CogLab If you stare at the middle of face, the information on the left goes to the right hemisphere which is supposed to be better able to deal with face information than the left hemisphere So the information on the left side of the face should dominate the face decision This face should look relatively old Purdue University CogLab So, we would expect people with brain asymmetries would usually choose as younger, the face that has the younger half on the left side Left handed people typically do not show as much brain asymmetry effects as right handed people Thus, we can look for differences between left and right handed people We expect right handed people to select the face with the younger image on the left more often than left handed people Purdue University CogLab Here is the data average for the class 191 right handed people 15 left handed people In the right direction, but a small effect Left handed Right handed Percentage of choices with younger face on left 50.95 56.13 Purdue University CogLab Here is the data average for the global data set 16,056 right handed people 1676 left handed people Some evidence of a very weak effect Left handed Right handed Percentage of choices with younger face on left 56.4 57.2 Purdue University Anatomy The cortex contains large fissures that separate five major areas Limbic (already discussed) Occipital Parietal Temporal Frontal Each has distinct propertiesProf. Greg Francis 1/2/12 PSY 200: Intro. to Cognitive Psychology 5 Purdue University Occipital lobe Receives information from the eye Most investigated area of the brain Purdue University Parietal lobe Primary sensory area Sensations of pain, temperature, touch, pressure Purdue University Parietal lobe Primary sensory area sensitivity involves disproportionate areas of the brain, relative to size of body part Purdue University Temporal lobe Hearing speech (left) music (right) Memory and attention visual recognition Purdue University Frontal lobe Largest part of cortex planning prediction motor area speech area Purdue University Broadman areas Divide lobes into areas e.g. Broadman Area 1, Area 12, … Area 200 Some special names: V1, V2,
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