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Flashcards in Brain Rhythms/EEG/Sleep Deck (16)
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3.6 Behavioral States

Conscious: alert to drowsy
Sleep: NREM (EEG synchronized) and REM (desynchronized)
Unconscious: comatose and persistent vegetative



Partial or nearly completely unconscious in which person can be aroused only briefly and with very strong repeated stimuli


Reticular Activating System

Runs from reticular formation in brainstem to diffuse thalamocortical projections to control level of excitability in cerebral cortex by delivering EPSPs. Afferent input (like medial lemniscus) stimulates it


Primary vs. Secondary Response

First, from somatosensory specific projection systems vs. second from reticular formation and diffuse projection systems


Blocking Primary and Secondary Responses

Only by lesioning specific projection nuclei of thalamus vs. anesthesia



Anesthetic agents that make IPSPs longer and EPSPs shorter


Synchronous vs. Asynchronous Brain Waves

When not thinking or w/e, dendrites just run at rate of RAS so brain waves are larger. When are thinking, neurons firing at different rates so they cancel out and brain waves smaller


Alpha and Beta Rhythms

8-13 Hz, larger rhythm when awake but eyes closed vs. when eyes open or thinking about problem


Brain Waves of Sleep

REM is in alpha or beta, deep sleep is in Delta (largest jumps, most disconnected from RAS)


3 Kinds of Epilepsy

Tonic-Clonic Seizures: overactivity of RAS causing everything to go off
Absence Seizures: maybe overactivity of inhibitory circuits causing blackout for few seconds
Focal Epilepsy: from injury to one side of brain, spreads waves of excitability and contracts contralateral muscles


Sleep Progression

Go from N1/N2 to N3/N4 (light to deep sleep), then return back through to N1 where you go to REM sleep


Sleep Spindles

Bursts of alpha rhythm activity in N2 that might be bursts of RAS or to inhibit it?


3 Functions of Sleep

Memory consolidation
Reduce dominant circuits to maintain stability
Work underused circuits so they aren't lost


Suprachiasmatic nucleus (SCN)

Pacemaker for circadian rhythm


Persistent Vegetative State

Higher cortical centers are nonfunctional, but brain stem still is so reticular formation keeps them in states of arousal and sleep


Difference between Coma and Persistent Vegetative State

Sleep/wake cycles