Chapter 6: Consciousness and Sleep Flashcards
Consciousness
- Consciousness is an individual’s awareness of oneself and the environment.
- Throughout the day, mood, alertness, efficiency, and consciousness itself are in perpetual flux.
- Changing states of consciousness are often associated with biological rhythms.
Biological Rhythms
- A periodic, more or less, regular fluctuation in a biological system.
- Rhythms can be synchronized with external Ientrainment) or internal cues (endogenous).
- Biological rhythms influence effectiveness of medication, alertness, job performance.
Circadian Rhythms
- Occur approximately every 24 hours (e.g., sleep-wake cycle)
- Commonly entrained to external time cues.
- Endogenous rhythm averages 24.3 hours.
- Controlled by biological clock in suprachiasmatic nucleus (SCN)
- Regulates levels of melatonin secreted by pineal gland.
Internal Desynchronization
- A state in which biological rhythms are not in phase (synchronized) with one another.
- Change in your normal routines can cause desynchronization
- May also occur in response to jet lag, rotating shift work, daylight savings time.
Seasonal Affective Disorder (SAD)
A disorder in which a person experiences depression during the winter and an improvement of mood in the spring.
- Treatments may involve phototherapy or exposure to fluorescent light.
- Inconsistent findings with respect to prevalence (2-20%) and effectiveness of treatments.
How often do we cycle between periods of REM and non-REM sleep?
~90 minutes. REM lengthens through the night.
Rapid eye movement (REM)
characterized by eye movement, loss of muscle tone, and dreaming.
- Active brain but inactive muscles
Non-REM (NREM) sleep
Characterized by fewer eye movements than in REM.
- Divided into 4 stages with different brain waves.
- Relaxed brain associated with alpha waves.
Alpha waves
Brain activity during a state of relaxed wakefulness
NREM-1
Period when the sleep is on the edge of consciousness, in a light sleep
NREM-2
Sleep stage characterized by short bursts of rapid waves
NREM-3
Sleep stage characterized by very slow waves with high peaks
What certain processes does sleep allow to occur?
- Body eliminates waste products from muscles
- Repairs cells
- Conserves and replenishes energy stores.
- Strengthens immune system
- Recovers abilities lost during the day
- Necessary for normal mental functioning
Chronic sleep deprivation
increases cortisol levels which can impair neurons involved in learning and memory. Higher risk for disease, illness and death.
Chronic insomnia
Difficulty falling or staying asleep; about 3.3 million Canadian adults experience this. May be a modest corellation between lack or amount of exercise and ability to falling asleep. If you excerise it becomes easier to fall asleep.