03 Consciousness and Sleep Free Online FlashCards

What is consciousness?

Consciousness is awareness of oneself and the surrounding environment, including sensations, thoughts, memories, emotions, and intentions.

How does consciousness vary?

Consciousness varies in level and content. Alertness, drowsiness, sleep, hypnosis, intoxication, and unconsciousness represent different states or conditions.

What functions does sleep support?

Sleep supports attention, learning, memory, emotional regulation, and normal physical functioning. Sleep loss can impair memory and cognitive performance.

What is Process S?

Homeostatic sleep drive, or Process S, is the pressure to sleep that increases during wakefulness and decreases during sleep. Adenosine contributes to this pressure.

What is Process C?

Circadian process, or Process C, is an internal timing system that promotes wakefulness during the biological day and sleep during the biological night.

What characterizes N2 sleep?

N2 is light but stable sleep marked by sleep spindles and K-complexes on EEG. These patterns are associated with sensory processing and sleep stability.

What characterizes N3 sleep?

N3 is deep, slow-wave sleep dominated by large delta waves. It is difficult to interrupt and is associated with physical restoration and some memory processing.

What happens during REM sleep?

REM sleep includes rapid eye movements, relatively active brain activity, and temporary inhibition of most skeletal muscles. Dreaming is common but can also occur in NREM sleep.

What is known about the function of dreams?

Dreams are sequences of perceptions, thoughts, emotions, and images during sleep. Their exact purpose is not fully known, and no single theory is conclusive.

What controls the central circadian clock?

The suprachiasmatic nucleus (SCN), a group of hypothalamic neurons, is the central biological clock. Light detected by the eyes is its most important environmental resetting cue.

What is melatonin’s main role?

Melatonin is released more in darkness by the pineal gland. It signals biological night and helps coordinate sleep timing; it is better understood as a timing signal than a sedative.

What is an altered state of consciousness?

An altered state of consciousness is a temporary pattern of mental functioning that differs substantially from ordinary waking awareness in areas such as attention, perception, time, or self-awareness.