PSY 1101 Lecture Notes - Lecture 8: Hypopituitarism, Twin, Orexin

• School: University of Ottawa
• Department: Psychology
• Course: PSY 1101
• Professor: Kenneth Campbell

Document Summary

Drive increases vs drive reduction (provide sweetness but fewer calories: what triggers the feeling of hunger? although the hunger drive is decreased. Hypothalamic regions for hunger: lateral, ventromedial, homeostasis, lower set point. Lateral hypothalamic: food deprived: release orexin, stimulation results in massive overeating, lesions result in animal refusing to eat. Ventromedial hypothalamus: stimulation results in starvation, lesions cause animals to eat huge quantities, several hormones may be released by the stomach and intestines signaling fullness, other sites (stomach and intestines) Problems central signal: (cid:498)set point(cid:499) in lateral hypothalamic animals of force-fed, (cid:498)set point(cid:499) in ventromedial animals energy, metabolic rate. Animals on a semi-starvation diet reduce activity to conserve. Some preferences are universal & thus genetic (for sweet and salty) Other tastes are conditioned (learned: ecology of eating. We tend to eat more with other (facilitation) Unit bias we"ll eat more if presented with large compared to small portions.