3 methods to assess sleep:
- Poly Sonography (EEG Data)
- Actigraphy Watch
- Questionnaires
Stage of sleep characterised by small waves of front-central theta activity (4-7hz) + enhanced Beta activity + Drowsiness + muscle twitching
Stage 1
Stages of sleep characterised by Delta waves (1-4hz)
Stage 3 & 4 => SWS
Sleep stage dominated by theta waves (4-7Hz) + energy burst sleep spindles
Stage 2
Deepest stage of sleep
Stage 4 - SWS
Growth Hormone released in
Stage 4 - SWS
Sleep stage: Fast desynchronised EEG ==> theta/beta activity with brief alpha rhythm
REM sleep/Paradoxical sleep
Body during REM
muscles relax (muscle atonia)
heart increases
breathing is rapid and shallow
% of time in REM sleep
20-25%
% of time in Stage 4
12-15%
Longest sleep stage
Stage 2 - 45-55%
adults sleep cycle
90 minus
infant = 50-60 minutes
SREM
slow rolling eye movemnet - happens in stage 1 and stops in stage 2
K complexes
found in stage 2 alongside theta waves
Which stage of sleep declines as we get older
SWS
no eye movement occurs in
SWS
EEG desynchronization
The EEG background activity changes from that seen in slow wave sleep (stage III or IV)
What happens to SWS in child development
Steep Decline
Stage 2 = stable
SWS in the brain throughout the development
Posterior => Central => Frontal
Matches the course of cortical maturation – possibly contribute to cortical development
In which brain region does SWS occur in 1 and 2 years old?
Occipital region
- coincides with visual acuity
SWS occurs in _ brain region between 17-20 years old
Fronto region - coincides with EF development
Active System Consolidation
Theory on sleep & cognitive development
According to ASC theory what happens to memories in sleep
Memories move from:
Hippocampus (temporary store) ==> Neocortex (Long Term Store)
neuronal reactivation of declarative memory during slow-wave sleep (SWS) promotes the redistribution of representations initially stored in hippocampal circuitry to extra-hippocampal circuitry for long-term storage.
EEG support for ASC
neocortical – slow oscillations
Thalamo-cortical – K complexes (spindles)
Hippocampal ripples
What is synaptic Homeostasis
Sleep & cognitive development Theory
- Sleep allows the brain to normalise and rest
How does sleep promote cognitive development according to SH theory
It provides:
Motor disconnection
Sensory disconnection
the proposed function of sleep is to provide synaptic renormalization, which has important implications with respect to energy needs, intracranial space, metabolic supplies, and, importantly, enables further plastic changes.
What sleep waves potentiate memories?
SWS oscillations
Benefit of sleep & memory consolidation was associated with…
SWS
in Epilepsy patient and TD
What discharges are associated with negaitve impact on memory consolidation
Interictal
