PSY 120 Lecture Notes - Lecture 5: Circadian Rhythm, Seasonal Affective Disorder, Chronotype
Document Summary
Body rhythms and mental states: biological rhythms: the tides of experience. Understanding biological rhythms: biological rhythms, a periodic, more or less regular fluctuation in a biological system, rhythms can be synchronized with external (entrainment) or internal cues (endogenous, biological rhythms influence effectiveness of medication, alertness, job performance. Endogenous biological rhythms: circadian rhythms, occur about every 24 hours, example:the sleep-wake cycle. Infradian rhythms: occur less often than once a day, examples include birds migrating, bears hibernating, menstrual cycle, ultradian rhythms, occur more frequently than once a day, about every 90min, examples include stomach contractions and hormone levels. Circadian rhythms: occur in plants, animals, insects and people. To study circadian rhythms, scientists isolate volunteers from time cues: what has been found, supraciasmatic nucleus (scn) Located in the hypothalamus, responsible for circadian rhythms by regulating melatonin, a hormone secreted by the pineal gland.
