PSYB64H3 Lecture Notes - Lecture 8: Suprachiasmatic Nucleus, Seasonal Affective Disorder, Non-Rapid Eye Movement Sleep
Document Summary
Week 8 july 6 th , 2015. Circadian rhythms: biological cycles can vary in length. The human menstrual cycle is about a month. Infradian: rhythms that are longer than 24 hours. Zeitgebers: any external cue that synchronizes an organism"s internal clock. Larks: people who wake up early in the morning. Night owls: people who stay up late and sleep in: typical in adolescents, melatonin drops at the onset of puberty. Shift work, jet lag, and daylight saving time: shift maladaptation syndrome, it is easier to adjust to phase-delay than a phase-advance. Daylight saving time in spring requires a phase advance, and can produce symptoms similar to jet lag. The time change in fall is equivalent to a phase delay, and causes little disruption for most people. Free-running period: a rhythm that is not synchronized to environmental time cues (i. e. , natural light). Entrainment: the resetting of internal biological clocks to the 24-hour cycle of the earth"s rotation.
