Sleep and the EEG Flashcards
alpha waves
quiet wakefullness with eyes closed 8-13 Hz Occipital cortex disappears during sleep Requires: thalamocortical connection
Beta waves
Alert wakefullness with eyes opened
14-80 Hz
frontal cortex with some parietal cortex
Alerting Response aka Alpha block
sensory input allows the transition from alpha to beta waves
*when you close your eyes alpha waves will reappear
Gamma waves
30-80 Hz
individual is aroused or focused
***planning a motor response
hippocampus
Theta waves
Hippocampus
4-7 Hz
children: parietal and frontal cortex
adults: frustration/disappointment/sleep
Delta waves
biggest and slowest
less than 3.5 Hz
*deep sleep in adults
found in infants
–if found during wakefullness=sign of brain diseas
demonstrates a thalamocortical disconnection
Suprachiasmatic nucleus
Circadian rhythms
-heavy genetic influence
BMAL
Increases at night to increase translation of PER/CRY genes
CLK
Constant throughout the day
-functions to increase translation of PER/CRY genes
PER/CRY
products inhibit the release of BMAL and CLK
Glutamate
released during day light to inhibit the pineal gland to stop melatonin release
Melanopsin
provides light and dark info
***No visual tract input
goes thru the retinohypothalamic tract
Retinohypothalamic tract
relays melanopsin to give info about light/dark
Infancy Patterns
fast beta like activity
slow over the occipital region
What causes a decrease in the frequency of alpha waves?
- hypoglycemia
- low body temp
- low adrenal glucocorticoids
- high PaCO2