States of consciousness

Your awareness of everything that is going on around you and inside your own head at any given movement, which you use to organize your behavior.

• Consciousness

• Circadian Rhythm

• Insomnia

• Hypnosis

Much of people’s time awake, in which their thoughts, feelings, and sensations are clear and organized, and they feel alert.

• Waking Consciousness

• Altered State of Consciousness

• Hypnosis

• Dissociative State

Occurs when there is a shift in the quality or pattern of your mental activity. Thoughts may become fuzzy, disorganized and you may feel less alert, or your thoughts may take bizarre turns, as they so often do in dreams.

• Altered State of Consciousness

• Waking Consciousness

• Hypnosis

• Narcolepsy

The sleep-wake cycle.

• Circadian Rhythm

• Sleep Deprivation

• Microsleep

• Rapid Eye Movement (REM) Sleep

Loss of sleep.

• Sleep Deprivation

• Microsleep

• Narcolepsy

• Non-REM Sleep

Brief bursts of sleep lasting only seconds.

• Microsleep

• Circadian Rhythm

• Rapid Eye Movement (REM) Sleep

• Sleep Apnea

A relatively psychologically active type of sleep when most of a person’s dreaming takes place; voluntary muscles are inhibited, making the person move very little.

• Rapid Eye Movement (REM) Sleep

• Non-REM Sleep

Spans from lighter stages to a much deeper, more restful kind of sleep; the person’s body is free to move around in this stage.

• Non-REM Sleep

• Rapid Eye Movement (REM) Sleep

A machine that allows scientists to record the brain-wave activity as a person passes through the various stages of sleep and to determine what type of sleep the person has entered.

• Electroencephalography (EEG)

• Positron Emission Tomography (PET) Scan

• Computed Tomography (CT or CAT) Scan

• Magnetic Resonance Imaging (MRI)

The inability to get to sleep, stay asleep, or get a good quality of sleep.

• Insomnia

• Sleep Apnea

• Narcolepsy

• Microsleep