Intellectual and Behavioral Functions

1. 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. 14.22

2. 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

3. Guyton, Medical Physiology cf. Fig.14.25 and p. 558 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

4. categorical hemisphere left hemisphere verbal skills analytical skills representa-tional hemisphere right hemisphere visual, spatial and aural skills emotional perception Hemispheric Lateralization Fig. 14.26 • 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.

5. 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. Dominance and Creativity Fig. 14.16

6. Reasoning Phineas Gage’s injury Fig. 15-1 Ganong • 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 … . cf. Fig. 14.20 http://content.nejm.org/content/vol351/issue23/images/data/e21/DC1/e21v2.mpg 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.

7. Memory and Learning • habituation • decreased response to unimportant stimuli • sensitization • increased response to important stimuli

8. 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. 12.30

9. 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 http://www.sahs.uth.tmc.edu/brainsurf/aplysia1.html

10. 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. Memory and Learning Fig. 14.17

11. 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) Memory and Learning

12. EEG • measures cortical activity • On your own: p. 536 • one or two phrases for each pattern for adults Fig. 14.18