PSY 260 Lecture Notes - Lecture 9: Retinal Ganglion Cell, Pineal Gland, Alpha Wave
Document Summary
Biological rhythms: regular uctuation in the living process, types. Circadian rhythms: have a period of about 24 hours: generated by an internal clock. Located in the suprachiasmatic nucleus (scn) in the hypothalamus: pineal gland releases melatonin to inform brain about day length, birds/amphibians. Light reaches scn/pineal gland directly (skull is thin enough: mammals. Suggests humans rely heavily on light and retinohypothalamic pathways. Light information travels to scn via the retinohypothalamic pathway. Damage to this would cause inability to create rhythm without cues (such as light: experiments show. Transplants followed donor"s clock: genetic basis. Gene mutations: tau: shorter than normal, double clock: severe arrthytcmitcity, per and clock are associated with different human chronotypes (morning vs. night person, free-running animal: maintaining its own cycle with external cues (has a constant environment) Periods for these animals are usually a little more than 24 hours: period: time between successive cycles. Ultradian rhythms: repeat more than once a day (hormone release, feeing, activity, etc. )
