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?
alpha
beta (2 types)
delta
theta
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)