Intellectual and Behavioral Functions Cerebral Cortex –frontal lobe: somatic motor cortex –primary sensory areas: first part of cortex to receive sensory information parietal lobe: somatic sensory cortex occipital lobe: visual cortex temporal lobe: auditory cortex –association areas / interpretive areas: perception of patterns of sensation lines, edges, and color associated into an image sounds associated into a word Fig

Intellectual and Behavioral Functions –common integrative area / general interpretive area somatic, visual and auditory association areas meet together sensory patterns coordinated into a thought Guyton, Medical Physiology

Example of Cortical Pathways word seen –visual cortex word understood –visual and general interpretive area thought develops to speak the word –Wernicke’s area [left cerebral hemisphere] speech coordinated –Broca’s (motor speech) area [left cerebral hemisphere] signals sent to cortical areas that control muscles of speech Guyton,MedicalPhysiology cf. Fig and p. 558

Hemispheric Lateralization These general patterns are true for nearly all right-handed people and two-thirds of left-handed people. Sex differences exist: e.g., lateralization is more pronounced in males, whereas verbal skills are more broadly distributed in females. categorical hemisphere –left hemisphere –verbal skills –analytical skills representa- tional hemisphere –right hemisphere –visual, spatial and aural skills –emotional perception Fig

Dominance and Creativity It is incorrect to call the left hemisphere “dominant.” The 2/3rds of left handed people whose left hemisphere is categorical show that motor control and verbal/categorical skills can exist on different hemispheres. Creativity, if it’s to be effective, also needs planning and analysis. Therefore, creativity is not a specialized “right- brain” function, but requires good function of and good communication between both hemispheres. Fig

Reasoning Prefrontal Area: control and elaboration of thought –planning, problem solving, concentration, delayed gratification, social control –Lesions cause loss of ambition, inability to perform complex tasks, rapid changes in emotions, loss of embarrassment …. Phineas Gage’s injury Lobotomies used to be performed on psychotic persons (fewer signals sent to limbic system / less aggression). The patients became more docile; the price - loss of their previous personality. Fig Ganong cf. Fig

Memory and Learning habituation –decreased response to unimportant stimuli sensitization –increased response to important stimuli

Memory and Learning short-term memory –temporary (seconds to hours) –quickly recalled / quickly replaced –possible mechanisms reverberating circuits parallel circuits relatively long lasting EPSPs and IPSPs Fig

Memory and Learning long-term memory –hours to years –due to structural change in neural circuitry changing the number of synapses changing the quality of synapses –protein synthesis required »receptors: changing type, number, function »channels: adding or deleting e.g., to change [Ca ++ ] cytosol –Aplysia

Memory and Learning consolidation –conversion of short term to long term memory –requires rehearsal –hippocampal function medial portion of temporal lobe –Alzheimer Disease includes a loss of cholinergic stimulation of the hippocampus. anterograde amnesia: inability to store new memories; past memories remain cf. retrograde amnesia: inability to recall past events –Trauma can cause loss of recently stored memories. Fig

Memory and Learning Memories are stored throughout the cortex. For rats –sensory-rich environment  thicker and more convoluted cerebral cortex more cortical area for memory storage? –mobiles over baby cribs (cf. detrimental effects of television)

EEG measures cortical activity On your own: p. 536 –one or two phrases for each pattern for adults Fig