Psyc2650

CHAPTER 2: THE NEURAL BASIS FOR COGNITION EXPLAINING THE CAPGRAS SYNDROME Capgras syndrome: patients with the syndrome are able to recognize people in their world but are convinces that these people are not who they appear to be – they are imposters What is going on? Facial recognition involves two separate systems in the brain (1) cognitive appraisal: I know what my father looks like (2) emotional appraisal: I know you and you trigger a warm response Capgras syndrome: the emotional processing is disrupted; leading to an intellectual identification without familiarity response Neuroimaging techniques: A method for examining either the structure or the activation pattern within a living brain THE NEURAL BASIS FOR CAPGRAS SYNDROME One site of damage is the temporal lobe on the R side of the head – disrupting the amygdala Amydala “emotional evaluator”: An almond-shaped structure in the limbic system that plays a central role in emotion and in the evaluation of stimuli. With a damaged amygdala: pts with Capgras syndrome won’t experience the warm sense of feeling good when look at a loved one’s familiar face Another site of damage: frontal lobe; R prefrontal cortex Prefrontal Cortex: The outer surface (cortex) of the front most part of the brain (i.e., the front most part of the frontal lobe). The prefrontal cortex has many functions but is crucial for the planning of complex or novel behaviors, so this brain area is often mentioned as one of the main sites underlying the brain's executive functions. The damage to the frontal lobe: pts with Capgras syndrome; are less able to keep track of what is real and what is not WHAT DO WE LEARN FROM CAPGRAS SYNDROME? Recognition of all stimuli involves two separate mechanisms; one that hinges on factual knowledge and one that’s more “emotional” Amygdala also plays an important role in remembering the emotional events in their lives; on decisions that require emotional evaluations Our emotional evaluator works in a fashion separate from evaluation of factual information Simple tasks require coordination of different areas in the brain; if this is disrupted than other areas of the brain work to ensure the task is completed. THE STUDY OF THE BRAIN Case study: Phineas Gage – rod went through his frontal lobe – led to personality and emotional problems HINDBRAIN, MIDBRAIN AND FOREBRAIN HIINDBRAIN Hindbrain sits directly on top of the spinal cord – includes structures important for life functions Largest area is the Cerebellum: coordination of bodily movements and balance; spatial reasoning, integration of input MIDBRAIN Coordinates movements; skilled/precise movement of eyes Auditory information from ears to areas of the forebrain FOREBRAIN Largest region Outer surface is the Cortex: The outermost surface of an organ in the body; psychologists are most commonly interested in the brain's cortex and, specifically, the cerebral cortex Convolutions: the wrinkles visible in the cerebral cortex that allow the enormous surface area of the human brain to be stuffed into the relatively small volume of the skull Longitudinal Fissure: The separation dividing the brain's left cerebral hemisphere from the right. Frontal Lobe: Form the front of the brain right behind the forehead. Central Fissure: The separation dividing the frontal lobes on each side of the brain from the parietal lobes. Parietal Lobe: The lobe in each cerebral hemisphere that lies between the occipital and frontal lobes and that includes some of the primary sensory projection areas, as well as circuits that are crucial for the control of attention. Lateral Fissure: The separation dividing the frontal lobes on each side of the brain from the temporal lobes. Temporal Lobe: The lobe of the cortex lying inward and down from the temples. The temporal lobe in each cerebral hemisphere includes the primary auditory projection area, Wernicke's area, and, subcortically, the amygdala and hippocampus. Occipital Lobe: The rearmost lobe in each cerebral hemisphere, and the one that includes the primary visual projection area. SUBCORTICAL STRUCTURES