Quick questions on Consciousness, Sleep and Dreaming - TCE Psychology (Tasmania)

Normal waking consciousness (NWC) is the state of clear awareness of yourself and your environment when awake and alert, with controlled, selective attention and an accurate sense of time. An altered state of consciousness (ASC) is any state that differs noticeably from NWC, such as sleep, daydreaming, hypnosis, meditation, or states induced by alcohol or other drugs. ASCs typically involve changes in attention, perception, time orientation, emotional awareness and self-control.

Because consciousness is private, psychologists use both objective physiological tools and subjective self-report.

Sleep cycles through non-REM (NREM) and REM stages roughly every 90 minutes. NREM has stages of progressively deeper sleep, with slow delta waves dominating the deepest stage and the body repairing tissue. REM (rapid eye movement) sleep shows fast, awake-like brain waves, darting eyes, near-total muscle paralysis (atonia), and is when most vivid dreaming occurs. Across a night, NREM dominates early and REM periods lengthen toward morning.

Going without sufficient sleep produces a sleep debt. Effects include impaired concentration, slowed reaction time, irritability, poorer memory consolidation and, with severe deprivation, microsleeps and even hallucinations. Partial sleep deprivation (too little sleep) is more common than total deprivation, and its cognitive and emotional effects accumulate over successive nights.