PSC 154 Chapter Notes - Chapter 6: Cerebral Cortex, Limbic System, Motor Coordination
Brain mechanisms & emotion
● Human brain has about 100,000,000,000 neurons
● Noninvasive imaging
○ PET
○ fMRI
●
○ Medulla - regulates cardiovascular activity
○ Pons - controls sleep & breathing
○ Cerebellum - motor coordination & automatic movements
○ Forebrain includes thalamus, hippocampus, & hypothalamus
■ Thalamus - integrates sensory info
■ Hippocampus - critical for memory processes
■ Hypothalamus - involves important biological functions like eating, sexual
behavior, aggression, & bodily temperature
■ Forebrain also includes limbic system
● Includes amygdala & cerebral cortex
● Cannon & Bard
○ Found that cats deprived of their cerebral cortex made sudden, inappropriate, &
ill-directed attacks
○ Called “sham rage”
● MacLean
○ Argued that the human forebrain includes 3 distinct systems, that evolved at
different times & that each fulfill a certain function
○ Striatal region
■ Became enlarged w/ the evolution of reptiles
■ Devoted to scheduling & generating basic behaviors (ex: preparing a
home, patrolling territory)
■ When striatal areas are damaged, ppl are unable to organize daily
activities
● Ex: Huntington’s chorea
● Ex: encephalitis lethargica
○ Patients w/ this also hade damaged striatal region
○ Argued mammals have maternal caregiving w/ infant, vocal signaling, & play
■ All of these are served by limbic system
○ Argued mammals diverged from reptiles in evolution & the limbic system
developed
○ He removed parts of limbic system from wild monkeys
■ Results - monkeys (normally aggressive) beame docile, hypersexual,
disinhibited, & approached everything w/o fear
○ Argued limbic system is centrally involved in emotion
● 6 brain regions involved in emotional response (Kober and Wager)
○ Hypothalamus, amygdala, periaqueductal gray, visual cortex, regions to the back
of brain involved understanding others and bodily awareness, & regions in frontal
cortex
