PSY397H1 Lecture Notes - Lecture 3: Pineal Gland, Master Clock, Zeitgeber
Document Summary
Chapters 10, 11: readings h, i, j, k, review chapter 6, 7. Circadian clocks synchronize with zeitgeber --> selected for precision rather than accuracy. If the clock has a period different of the thing it"s measuring, it will give the wrong answer. It needs to be very accurate or be set everyday. Biological clock cannot be exactly 24h because it needs to be able to shift a little bit if things change --> twilight and dusk is where it is determined (it wouldn"t be able to be settable) Most cases: primary circadian zeitgeber is schedule of ld, providing regular events. Entrainment to l/d allows organisms to anticipate the long term occurrences of important regularly occurring conditions. These are for events that occur on a regular basis. Nonphotic signals produce circadian phase shifts and modulate the circadian system"s responses to light. These are often not chosen as the primary zeitgeber.
