Sleep Flashcards
What does an EEG measure?
β The combined activity of a large number of similarly orientated neurons
What does an EEG require?
β synchronous activity across groups of cells
What does the amplitude of an EEG signal depend on?
β how synchronous the activity of the neurons are
What is a large summed signal caused by?
β tiny signals summed up to generate a large surface signal
What is a small summed signal caused by?
β the same amount of excitation as a large signal
β but at irregular intervals
What do EEG rhythms correlate with?
β States of behaviours
What is high frequency and low amplitude associated with?
β Alertness and wake
What is low frequency and high amplitude associated with?
β Non dreaming sleep or coma
What are the two theories of how rhythms are generated during sleep?
β There is a pacemaker that acts as a conductor (conductor telling everyone to clap)
β mutual excitation and inhibition and neurons sync to what other neurons are doing (people clapping at random and syncing to each other)
What is theorised to be the pacemaker in the brain and why?
β Thalamus
β thalamic nuclei communicate with every cortical brain structure
Describe the hypothesis for slow frequency and high amplitude rhythms during sleep?
β Thalamus acts as a gatekeeper it stops information getting to the brain during sleep
(like a spinning arm in an obstacle course)
Describe the hypothesis for fast frequency and low amplitude rhythms during wakefulness
β the brain is attention grabbing to bind together regions needed for task execution
What is sensation like in non REM sleep?
β dull or absent
What is thought like in non REM sleep?
β logical
β repetitive
What is movement like in non REM sleep
β occasional
β involuntary
What is sensation like in REM sleep?
β vivid
β internally generated