Chapter 5 Definitions

consciousness

The awareness of internal and external stimuli

electroencephalograph (EEG)

A device that monitors the electrical activity of the brain over time by means of recording electrodes attached to the surface of the scalp

biological rhythms

Periodic fluctuations in physiological functioning

circadian rhythms

The 24-hour biological cycles found in humans and many other species

electromyograph (EMG)

A device which records muscular activity and tension

electrooculograph (EOG)

a device which records eye movements

electrocardiograph (EKG)

A device which records the contractions of the heart

REM sleep

A deep stage of sleep marked by rapid eye movements, high brain waves and dreaming

non-REM sleep

consist of sleep stages 1 to 3, which are marked by the absence of rapid eye movements, modest amounts of dreaming and varied EEG activity

insomnia

A sleep disorder characterised by chronic problems in getting adequate sleep that result in daytime fatigue and impaired functioning

narcolepsy

A disease marked by sudden and irresistible onsets of sleep during normal waking periods

sleep apnea

a sleep disorder involving frequent, reflexive gasping for air that awakens a person and disrupts sleep.

somnambulism (sleepwalking)

a sleep disorder, which occurs when a person arises and wonders about while remaining asleep

REM sleep behaviour disorder (RBD)

A sleep disorder marked by potentially troublesome dream enactments during REM periods

hypnosis

A systematic procedure that typically produces a heightend state of suggestibility

dissociation

A splitting of mental processes into two separate, simultaneous streams of awareness

Meditation

A family of practices that train attention to heighten awareness and bring mental processes under greater voluntary control

Psychoactive drugs

Chemical substances that modify mental, emotional or behavioural functioning

narcotics/opiates

drugs derived from opium that are capable of relieving pain

Sedatives

sleep-inducing drugs that tend to decrease central nervous system activation and behavioural activity

stimulants

drugs that tend to increase central nervous system activation and behavioural activity

Hallucinogens

A diverse group of drugs that have powerful effects on mental and emotional functioning, marked most notably by distortions in sensory and perceptual experience

cannabis

The hemp plant from which marijuana hashish and THC are derived

Alcohol

Encompasses a variety of beverages containing ethyl alcohol

tolerance

A progressive decrease in a person’s responsiveness to a drug as a result of continued use

physical dependence

when a person must continue to take a drug to avoid withdrawal illness

psychological dependence

When a person must continue to take a drug to satisfy intense mental and emotional craving