BioPsychCh9

Self generated rhythm that lasts about a year

Self generated rhythm that lasts about a day

• Stimulus that resets circadian rhythms
• Ex: Light, tide, noise, temperature..

Disruption of circadian rhythms due to crossing time zones

• Adrenal horomone
• Prolonged elevation of cortisol damages neurons in the hippocampus which is important for memory

• Introduced idea that the brain generates its own rhythms
• A biological clock

• Provides control of circadian rhythms for sleep/temperature
• Damage leaves rhytm inconsistent/no longer synced to light/dark patterns

• Photopigment from retinal ganglion cells
• Respond to light even without rods/cones
• Receive input from rods/cones
• See toward the periphery
• Respond to light slowly, turn off slowly when light decreases

• Released by pineal gland
• Influences circadian/circannual rhythms
• Is secreted at night- makes us sleepy 2-3 hrs before bed

• Extended period of unconsciousness
• Steady low level of brain activity

• Decreased brain activity
• Periods of sleep/periods of arousal
• Limited responsiveness
• Ex: Increased heart rate to pain

• Decreased brain activity
• Brief periods of purposeful actions
• Limited speech comprehension

• No sign of brain activity for 24+ hours
• No response to any stimulus

EEG + Eye movement records

• Rhythm of 8-12 brain waves per second
• Associated with relaxation

• 12-14 Hz waves during bursts
• Lasts 1/2 second
• Results from interaction between thalamus/cortex cells

• Sharp high amplitude wave
• Followed by small, slow, positive wave
• Most common in stage 2 of sleep

• Stages 3+4
• Slow, large amplitude brain waves

Deep sleep in some ways, light in others

• Light
• Paradoxical sleep
• Regular, low voltage fast waves
• Increased neuronal activity
• Deep
• Head muscles are most relaxed

• Part of reticular formation
• Contributes to cotrical arousal by axons releasing acetylcholine/glutamate in the basal forebrain/thalamus

• Dark blue space
• Small structure in the pons
• Inactive most of the time
• Bursts of impulses in response to emotional/meaningful events
• Silent during sleep

• Produced excitation throughout brain
• Cells that release histamine are active during arousal
• Less active around bedtime/early morning

• Peptide neurotransmitter
• Axons release it from basal membrane
• Necessary for staying awake

• Cells provide axons that extend throughout the thalamus/cerebral cortex
• Some release acetylcholine = exictatory/tends to increase arousal

prevent its axons from spreading stimulation to other areas

• REM sleep is associated with a distinctive pattern of high amplitude electrical potentials
• Waves first detected in pons, thalamus, then occipital cortex

Inadequate sleep

• Impaired ability to breathe while sleeping
• Caused by genetics, hormones..

• Frequent periods of sleepiness during the day
• 1) Sudden attack of sleepiness
• 2) Occasional muscle weakness- cataplexy
• 3) Sleep paralysis
• 4) Hypnagogic hallucinations - dreamlike experiences
• Treatment: Stimulant drugs (Ritalin)

Repeated involuntary movement of the legs/arms

Move around a lot and act out their dreams

• Intense anxiety
• occurr during NREM
• More common in children

Conserve energy

Dream represents the brain's effort to make sense of sparse and distorted information

Dreams begin with arousing stimuli that are made in the brain combined with recent memories and any info the brain is receiving from the senses