Psych: Brain Scans and Sleep

MEG

A brain imaging technique that measures magnetic fields from the brain's natural electrical activity.

MRI

A technique that uses magnetic fields and radio waves to produce computer-generated images of soft tissue. MRI scans show brain anatomy.

CT

A series of X-ray photographs taken from different angles and combined by a computer into a composite representation of a slice of the brain's structure.

PET

A technique for detecting brain activity that displays where a radioactive form of glucose goes while the brain performs a given task.

fMRI

A technique for revealing blood flow, and therefore brain activity, by comparing successive MRI scans. Shows brain function as well as structure.

Lesion

Tissue destruction. May occur naturally, during surgery, or experimentally.

hindbrain

Consists of the medulla, pons, and cerebellum; it controls essential survival functions such as breathing, sleep, and wakefulness, as well as coordination and balance.

midbrian

Found atop the brainstem, it connects the hindbrain with the forebrain, controls some motor movement, and transmits auditory and visual information.

Forebrain

consists of the cerebral cortex, thalamus, and hypothalamus; manages complex cognitive activities, sensory and associative functions.

Association Areas

Areas of the cerebral cortex that are not involved in primary motor or sensory functions, but rather are involved in higher mental functions such as learning, remembering, thinking, and speaking.

Insomnia

Recurring problems with falling or staying asleep.

Narcolepsy

A sleep disorder characterized by uncontrollable sleep attacks. The affected person may lapse directly into REM sleep, often at inopportune times.

Sleep Apnea

A sleep disorder characterized by temporary cessations of breathing during sleep and repeated momentary awakenings.

REM Sleep Behavior Disorder

A sleep disorder in which normal REM paralysis does not occur; instead, twitching, talking, or even kicking or punching may occur, often acting out one's dream.

Dream

A sequence of images, emotions, and thoughts passing through a sleeping person's mind.

REM Rebound

The tendency for REM sleep to increase following REM sleep deprivation.

Consciousness

our awareness of ourselves and our environment

Dual Processing

The brain processes information consciously and unconsciously at the same time.

Parallel Processing

The brain processes multiple pieces of information simultaneously.

Sequential Processing

The brain processes information one step at a time, in a specific order

Sleep

A periodic, natural loss of consciousness characterized by reduced activity and responsiveness.

Circadian Rhythm

The body's 24-hour biological clock regulates sleep, alertness, body temperature, and other functions.

Jet Lag

Fatigue and other symptoms caused by a disruption of the body's circadian rythm after traveling across time zones

EEG patterns

Brain-wave patterns measured by an electroencephalogram(EEG) that change during different stages of sleep.

Alpha Waves

Relatively slow brain waves associated with relaxed wakefulness, often occurring just before falling asleep.

NREM

Non-REM sleep consists of stages of sleep that do not include rapid eye movement.

Hypnagogic Sensations

Vivid sensations or experiences that occur as a person is falling asleep, such as feeling like you're falling or hearing a sound.

Delta Waves

Large, slow brain waves associated with deep sleep.

REM

Rapid Eye Movement sleep. A stage characterized by rapid eye movements, vivid dreaming, and brain activity similar to that of being awake.

REM Rebound

The tendency to experience more REM slep than usual after being deprived of REM sleep.

Suprachiasmatic Nucleus (SCN)

A group of neurons in the hypothalamus that acts as the body's main circadian clock and helps regulate the sleep-wake cycle.

Activation Synthesis Theory

The theory is that dreams result from the brain trying to make sense of random neural activity occurring during REM sleep.

Consolidation Theory

The idea that sleep, especially certain stages of sleep, helps the brian strengthen and store memories.

Somnambulism

Sleepwalking. Performing behaviors while still alseep, usually during deep NREM sleep.