PSYC 211 Lecture Notes - Lecture 28: Amygdala, Periaqueductal Gray, Fluoxetine

• School: McGill University
• Department: Psychology
• Course: PSYC 211
• Professor: Yogita Chaudasama

Document Summary

If the cs is presented alone repeatedly by itself, the cr, that is the emotional response of freezing, will eventually disappear o this is known as extinction: extinction is not the same as forgetting. In extinction, the animal learns that the cs is longer followed by and aversive stimulus o o therefore, the cr expression is inhibited. The memory of the association between the cs and the aversive stimulus is not erased; it can be reactivated. Neural correlates of aggressive behaviour: stimulating the periaqueductal gray matter (pag) in the midbrain of a cat, elicits predatory and defensive behaviour. The pag has excitatory and inhibitory connections with the hypothalamus and the amygdala which influence the overall expression of the emotional response. In humans, a depressed rate of serotonin release (indicated by low levels of 5-h1aa) is associated with aggression, assault and arson: drugs that increase the amount of serotonin in the synapse (e. g. prozac) decreases irritability and aggressiveness.