Intellectual and Behavioral Functions Cerebral Cortex –frontal lobe: somatic motor cortex –primary sensory areas: first part of cortex to receive sensory.
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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
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,Guyton,Medical Medical PhysiologyPhysiologycf. Fig.14.25cf. Fig.14.25and p. 558and 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. 14.26
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. 14.16
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. 15-1Ganong
cf. Fig. 14.20
http://content.nejm.org/content/vol351/issue23/images/data/e21/DC1/e21v2.mpg
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. 12.30
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
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. 14.17
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 adultsFig. 14.18
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