PSYA01H3 Chapter Notes - Chapter Final: Night Terror, Parahippocampal Gyrus, Reuptake
Document Summary
Cells in the retina of the eye relays messages about environmental light levels to the suprachiasmatic nucleus (scn) of the hypothalamus. The scn communicates signals to the pineal gland, causing it to release the hormone melatonin, which peaks in concentration at nighttime and is reduced during wakefulness: circadian rhythms change with age. We need much less sleep especially rem sleep as we get older. People also tend to experience a change in when they prefer to sleep. The stages of sleep: polysomnography refers to a set of objective measurements used to examine physiological variables during sleep, sleep cycles are most often defined by the electroencephalogram (eeg). These waves can be described by their frequency the number of up-down cycles every second and their amplitude the height and depth of the up-down cycle. Beta waves high-frequency, low-amplitude waves are characteristics of wakefulness. They are often interpreted as a sign that a person is alert.
