how do you measure brain waves on the surface of the skin?
using an electroencephalogram (EEG)
what are the 4 different types of brain waves?
- beta (2 types)
when does an EEG record alpha waves?
just before a person falls asleep
when are BETA 1 waves recorded?
- during average consciousness, normal wakefulness
- during REM sleep
- (high freq waves)
when are BETA 2 waves recorded?
- during a state of extreme wakefulness, high levels of excitement from elation, anger, etc
- highest freq wave
when are delta waves recorded?
- deep sleep
- (slow waves, almost straight lines)
when are theta waves recorded?
- not normal for these to be recorded in adults
- can be normal in the developing brain of a child
what is sleep?
- a disconnection btwn the thalamus and the cortex, the cortex falls asleep as a result
- not considered a vital function
what are the theories behind why we sleep?
- 1. fatigue - use up transmitters during the day
- 2. brain accumulates delta sleep peptide which shuts down the brain at a certain threshold
- 3. restore natural balances among the neuronal centers
what is wakefulness?
- a state of coordinated brain activity
- (means seizures occur in a non-wakeful state
what are the sleep cycle phases?
- 1st: Deep Sleep, compromises most of the sleep, lasts about an hour after first falling asleep, some dreams but no memories of them (no connection w/ thalamus)
- 2nd: REM, lasts 5-30 mins, dreams, uncontrolled activity
- repeats (aka paradoxical sleep), reoccurs every 90 mins or so, info from the thalamus is getting through
if a person is more tired than usual, will the duration of REM inc or dec?
true or false, a person is more easily awakened by sensory stimuli during REM sleep than deep sleep?
true or false, muscle tone is exceedingly depressed during REM sleep?
- true - strong inhibition of spinal muscle control areas
- but irregular muscle contractions will occur
by how much does brain metabolism inc during REM sleep?
as much as 20% - but activity is not channeled in the proper direction for person to be aware of surroundings, so they are asleep
by how much does BP, HR, and basal metabolism decrease during deep sleep?
true or false, most of the time brain waves are regular?
false, most of the time no specific pattern can be discerned