PS263 Chapter Notes - Chapter 8: Slow-Wave Sleep, Non-Rapid Eye Movement Sleep, Thalamus
Document Summary
State that the brain actively produces, characterized by decreased response to stimuli. Extended period of unconsciousness caused by head trauma, stroke or disease, low level of brain activity and little or no response to stimuli. Alternates between periods of sleep and moderate arousal. During aroused state person shows no awareness of surroundings and no purposeful behaviour. Brain activtity less than relaxed wakefulness but higher than other sleep stages. 12-14hz waves during burst, last at least half a second. Result from oscillating interactions between cells in thalamus and cortex. K complex: sharp wave associated with temporary inhibition of neuronal firing. Heart and breathing rate and brain activity decrease. Some view these 2 stages as 1 single stage called slow wave sleep. Slow waves indicate neuronal activity is highly synchronized. Sensory input to cerebral cortex is greatly reduced and many cells can synchronize their activity. Irregular, low voltage fast waves that indicate increased neuronal activity (light sleep)
