Conciousness Flashcards
Circadian rhythms
Variations in physiological processes that cycle within approximately a 24 hr period
Many physiological systems, including the sleep-wake cycle, feeding, hormone production and cellular regeneration vary on a circadian basis
Generated internally although seem to follow external cycle of day
Free-running rhythms
After a period of days or weeks of living in a time free environment display a free running rhythm of their own biological clock
Ultraradian rhythms
Cycles that are less than a day in length
Ie. rhythmic pattern in the brain during sleep is approximately 90mins
Rapid eye movement
Eyes moving rapidly under the eyelid during sleep
Accompanied by a specific patter of rapid EEG activity as well as low muscle tension
Beta waves
Brain activity characterized by rapid waves called beta waves when we are awake
Alpha waves
Occurs when we are awake but relaxed and drowsy
Also occur during R.E.M. Sleep, which is why it is also called paradoxical sleep
Non-rem sleep
Only 15-20 of our sleep is R.E.M.
Non-rem
Stage 1: brain waves change to theta waves (slower than alpha). Sensory curtains drop and so does responsiveness. Light sleep
Stage 1 of non-rem
brain waves change to theta waves (slower than alpha).
Sensory curtains drop and so does responsiveness.
Light sleep and not much needed to awaken
Stage 2 of non-rem
Occurs after about 7 mins in stage 1
Deeper stage requiring more intense sensory stimulation for arousal than stage 1
Predominantly theta waves
Also includes short periods of extremely fast and somewhat higher energy sleep spindles
Other unique marker is high energy k-complexes
Stage 3 of non-rem
Initially consists of theta waves, then more delta waves appear and fewer sleep spindles and k complexes
Stage 4 of non-rem
Occurs when there is complete absence of sleep spindles and k complexes
Contain highest proportion of slow delta waves
Aka slow wave sleep
Shortly after entering stage 4, go back to sleep spindles and k complexes of stage 3, then theta waves of 2 and 1
When we return to stage one our eyelids start to move again, then in R.E.M. And actively dreaming
Non-rem periods are shorter than rem
4-6 cycles of non-rem and rem every night in 90min cycles
Acoustic arousal threshold
Amount of sound required to awake someone
Largest in stage 4
Dreams
The succession of images, thoughts, and feelings we experience while asleep
Loosely connected by unusual association and not well recalled afterward
Continuity hypothesis
That the content of our dreams is related to events during our waking life
Psychoanalytic theory
Freud: the royal road to the unconscious
Dreams operate on 2 distinct levels of consciousness
Manifest level: the dream that we consciously recall after waking up is only the surface level
Latent level: deeper, unconscious level where the true meaning of the dream lies
Memory consolidation theory
Dreams are not that different from every day thinking
Standard processes such as imagery, memory etc operate in a similar manner during dreaming
Amount of time spent in rem sleep is longer after a period of new learning
Deprivation of rem can impair certain memory tasks, and block synaptic plasticity that accompanies new learning
Restoration theory
That we sleep in order for cells in our body to physically restore themselves
Sleep disorders
Insomnia, sleep apnea, sleep walking, narcolepsy, hypersomnia
Insomnia
Taking longer than 20 mins to fall asleep, having trouble staying asleep or not feeling rested after a nights sleep for 2 or more consecutive weeks
Affects 15-20% of adults
Drug treatments increase GABA activity
Sleep apnea
Temporary blockage of airway during sleep
Rarely fall into deep sleep and are sleep deprived
Narcolepsy
Excessive daytime sleepiness
May also experience cataplexy (weakness of facial and limb muscles)
May come from deficiency of orexin
Show abnormality in sleep spindles and disruption of rem sleeping patterns
Genetic basis
Hypersomnia
When a person sleeps more than 10 hrs per day for 2 weeks or more
Strong urges to nap
Suprachiasmatic nucleus (SCN)
Located in the hypothalamus and regulates physiological activity on daily cycles
Internal timekeeper
Light stimulates retina which stimulates SCN and signals pineal gland to decrease melatonin
Hypnosis
A state of mind that occurs in compliance with instruction and is characterized by focused attention, suggestibility, absorption and local of voluntary control over behaviour and suspension of critical faculties of mind
15% of population hypnotizable
