brain rhythms and wellbeing Flashcards
brain waves/rhythms
Activity of these neurons is to some extent synchronized in regular firing rhythms
what brain region has many neurones ?
cerebral cortex
how to measure brain waves
Hertz(Hz)
how is the cortical activity measured in EEG?
Electrodes placed on the scalp can pick up variations in electrical potential that arise from this underlying cortical activity
What are EEG signals affected by?
state of arousal of the cerebral cortex and show characteristic changes in different stages of sleep.
what external things are EEG signals affected by?
-stimulation of external environmentand brain waves can become entrained to external stimuli
what is Electroencephalography used to diagnose?
1.epilepsy
2. sleep disorders
3.diagnosis of brain death.
what do EEG result from?
slow changes in the membrane potentials of populations of cortical neurons
what 2 cortical neurones contribute to the result of EEG?
1.excitatory
2. inhibitory post-synaptic potentials (EPSPs and IPSPs, also known as field potentials)
what do EEG’s reflect?
algebraic sum of the electrical potential changes occurring from large populations of cells.
what do large amplitude waves require?
synchronous activity of a large number of neurons
where do rhythmic events that these waves reflect often arise?
thalamus whose activity is in turn affected by a variety of inputs including structures in the brainstem reticular formation
what happens to the alpha levels when eyes are open ?
alpha waves are reduced
what happens to the alpha levels when eyes are closed ?
seen as wakeful relaxation
what underpins higher cognitive functions?
Activation of the cortical circuitry in the pre-frontal cortex
what are examples of activation of cortical circuitry in the pre frontal cortex -which executive functions does this include?
1.planning
2.flexibility
3.working memory
4.task initiation
what does greater cortical activity leads to
lower alpha activity
what area of the brain is associated with reasoning and cognition?
frontal cortex
Polysomnography(PSG)
-evaluation of various behaviours in the lab and sleep conditions in a sleep clinic
-recording/observation of unusual movements during the experimental protocol, or for sleep disorders over an entire night’s sleep
what 5 disorders can PSG be helpful to detect?
1.sleep apnoea; for nocturnal seizure disorders
2.narcolepsy
3.periodic limb movement disorder
4.unusual movements
5. behaviours during sleep (parasomnias)
what physiological parameters included in a PSG
EEG (electroencephalogram)
EOG (electrooculogram)
EMG (electromyography)
ECG (electrocardiogram)
Plethysmography
Pulse oximetry
EEG (electroencephalogram)
record cortical activity
EOG (electrooculogram)
to record eye movement
EMG (electromyography
records muscle activity
ECG (electrocardiogram
record heart rate
Plethysmography
to record respiratory rate from the chest and abdominal walls
Pulse oximetry
to record oxygen levels in the blood
In PSG when the person has been recorded what other 2 things
1.body position
2. record vocal activity.
hypanpopmic episode
sleep to wake
hypnagogic episode
wake to sleep
What stage of the sleep cycle do night terrors generally occur in
stage 3-deep sleep
