L09 - Consciousness & Sleep Flashcards
What is consciousness?
A state of awareness of self and of the environment
What is Gestalt organisation?
Perceptions are interpreted into meaningful (familiar) information
What are the 3 steps from normal consciousness to coma?
1 - Clouding = drowsiness/agitation with memory disturbance and disorientation; impaired attention, concentration, recognition, comprehension, understanding and judgement
2 - Drowsiness = tendency to drift into sleep without sensory stimulation; slow actions, slurred speech, reduced reflexes and muscle tone
3 - Coma = reduced eye opening, verbal response and motor response
What is the difference between illusions and hallucinations?
- Illusion = abnormal perception of external stimulus
- Hallucination = perception in absence of external stimulus without subjective control
What are the 3 types of illusions?
- Completion illusions – you fill in the missing
gaps - Affective illusions – these are dependent upon an
individual’s mood state - Pareidolic illusions – these illusions arise due
to excessive fantasy thinking
What are the differences between a coma, minimally conscious state, and vegetative state?
- PVS - wakefulness with absent awareness
- MCS - wakefulness with minimal awareness
- Coma - absent wakefulness and absent awareness
What are the 3 types of dissociative disorders?
1 - Depersonalisation-derealisation disorder
2 - Dissociative amnesia
3 - Dissociative identity disorder
What is the behavioural definition of sleep?
Recurrent regular reversible state characterised by quiescence & diminished responsiveness to external cues
- Lack of mobility
- Closed eyes
- Reduced response to external stimulation
- Characteristic sleeping posture
- Reversible unconscious state
Which neural pathways are responsible for sleep and wakefulness?
- Wakefulness - aminergic (RAS) & orexin/hypocretin (LH)
- NREM - GABA (VLPO)
- REM - ACh (LDT & PPT)
What are the age-related changes to sleep?
- Total sleep time & sleep efficiency decreases
- Slow-wave sleep (NREM 3; deepest part) decreases; ? more in men
- Reduction in REM sleep
How are declarative and procedural memory consolidated?
Declarative memory (explicit – conscious recall of facts & knowledge) -> episodic, semantic:
- Consolidation in SWS if info simple & emotionally neutral
- Consolidation in REM if info complex & emotionally charged
Procedural memory (implicit – unconscious remembering ‘how’ to do something)
- Consolidated in REM
What are parasomnias?
- Slow-wave sleep disorders – stage 3 NREM sleep -> characterised by sleepwalking & night terrors
- REM sleep behaviour disorders – associated with presence of tone during REM sleep with active complex behaviours in absence of epileptiform activity
