LESSON 6 - NEUROSCIENCE: NEUROPHYCHOLOGY AND COGNITIVE NEUROSCIENCE Topic 1: The Central Nervous System . Describe how the structure of the central nervous system influences behaviour TOPIC 1: THE CENTRAL NERVOUS SYSTEM - "equipotential" - every bit of the brain does the same sort of thing in the same way without specialization. (know wrong from looking at differing of effects of brain injuries in different areas, different parts of brain activate for different tasks in imaging techniques) frontal lobe prefrontal lobe Broca's area parietal lobe occipital lobe - Evidence for specialized areas or localization of function = aphasia (loss of ability to speak) cerebellum temporal lobe pons Wernicke's Broca's aphasia (front left part of brain, understands language but can't speak, PATIENT = LEBORGNE (BRAIN LESION)) and Wernicke's aphasia (from left back part of brain, produces language but can't comprehend speech) medulla area - Brain imaging studies allow us to try to define problem (damage to what part = what changes in behaviour) - Ask participants to perform similar tasks differing in only one respect (ex: ask to repeat nouns and then ask to think of associated verb to noun, comparison shows where in brain does activity increase for comprehension rather than just repetition) o Left interior frontal gyrus important for generating verbs How are studies done? - Unintentional brain lesions (destruction of specific brain areas), look at how systems of functional loss relate to different sites of structural damage. Experimental control- make precisely localized brain lesions in animal species, repeat same damage, look at behavioural before/after changes - Brain Stimulation Studies- electrically stimulate brain directly, surgeons use to map cortex, Penfield maps cortex + creates map of mini body parts to represent areas of primary motor cortex and premotor cortex where stimulation caused those parts to move = homunculus (proportion of brain dedicated to certain areas, hands, face, tongue big) - Non - Human Stimulation/Recording microelectrodes placed in different subcortical structures of rats/others to locate structures that drive various behaviours (could result in sexual displays, eating behaviour, aggressive behaviour) - Human Brain Stimulation and Imaging Techniques - recently developed, stimulate subjects' brain and record localized brain activity in several different ways, techniques can be used to generate "maps" of human brain at work
Brain Structure - Motor activities - signals sent from brain/spinal cord through motor neurons to our muscles - Sensory activities Touch = parietal, Sight = occipital, sound= temporal, memory= frontal, limbic system = emotions. Facial Recognition important (way to identify people, convey emotional states, allow to navigate social life, other people = biggest stimulus) - *** Looks like walnut in shell or onion w/ many layers, newer structures at top, brainstem, cerebellum, hypothalamus in middle (only one each) - Left and Right Hemispheres: Together, the two hemispheres control much of your behaviour. The left is relatively more specialized for speech and language; the right, for appreciation of 3D space and spatial relationships. - Hemispheres connected by nerve fibres (axons), including colossal bundle called the "corpus callosum" -