Chapter 4 Definitions

Question 1

alpha waves

Answer 1

the typical brainwave pattern (reasonably high frequency (but not as high as beta waves) and low amplitude (but slightly higher than beta waves)) that occurs when awake but very relaxed

Question 2

amplitude

Answer 2

in terms of brainwaves, the height of the peaks and troughs of the curved graph that represents brain wave activity

Question 3

beta waves

Answer 3

typical brainwave pattern (high frequency (fast) and low amplitude (small)) during normal waking consciousness, associated with being alert, active, anxious and paying (selective) attention

Question 4

cataplexy

Answer 4

the total relaxation of muscles to the point of paralysis when in REM sleep.

also known as muscle atonia

Question 5

circadian rhythm

Answer 5

biological rhythms that occur approximately once every 24 hours, for example the sleep-wake cycle and body temperature

Question 6

deep sleep

Answer 6

collectively stage 3 and 4 NREM sleep

Question 7

delta waves

Answer 7

the typical brainwave pattern (a steady pattern of low frequency (slow) and high amplitude (large)) associated with NREM deep sleep.

Question 8

frequency

Answer 8

in terms of brainwaves, the number of brainwaves per second

Question 9

hypnogogic (hypnic) jerks

Answer 9

involuntary muscle twitches that causes us to jolt are common; usually experienced in Stage 1 NREM sleep (part of hypnogogic state)

Question 10

hypnogogic state

Answer 10

the relaxed state that occurs during the transition from being awake to being asleep, considered to be part of Stage 1 sleep

Question 11

hypnopompic state

Answer 11

the period between being asleep and waking up, a time when the the brainwaves are predominantly alpha waves. Vivid images (hypnopompic images) are often seen during the phrase

Question 12

K-complexes

Answer 12

brain wave patterns that consist of a sharp rise and fall in amplitude, lasting for about 2 seconds on the EEG. Indicative of stage 2 NREM sleep, occuring about once a minute although can be triggered by external stimuli (such as a loud noise)

Question 13

muscle atonia

Answer 13

the total relaxation of muscles to the point of paralysis when in REM sleep.

Also known a cataplaxy

Question 14

non-rapid eye movement (NREM)

Answer 14

one of two phases of sleep, characterised by little or none rapid eye movement, and often divided into our four stages of NREM sleep that are determined predominately by predominant brain wave patterns

Question 15

rapid eye movement (REM)

Answer 15

one of two phase (REM and NREM) of sleep, characterised by rapid eye movement

Question 16

restorative (restore and recover) theories of sleep

Answer 16

sleep allows us to recharge our bodies, recover from the physical and psychological work during the day and allow our body’s growth processes to occur

Question 17

sawtooth waves

Answer 17

associated with REM sleep; a special type of theta-like brainwave pattern that resemble the blade of a saw that may be found amongst the random and fast beta-like waves, especially when there is a burst of rapid eye movement

Question 18

sleep spindles

Answer 18

brain wave patterns that consist of rapid bursts of high frequency, often associated with stage 2 NREM sleep but can be found in stage 3 and 4 NREM sleep

Question 19

slow wave sleep

Answer 19

collectively stage 3 and stage 4 NREM sleep

Question 20

somnambulism

Answer 20

sleep walking

Question 21

survival (adaptive and evolutionary) theories of sleep

Answer 21

sleep serves as a means to increase an animals chances of survival in its environment - it allows us to adapt to our environment and depends on how much food we need, how available it is (we may need to conserve energy) and how safe it is when we need sleep. These sleep requirements have evolved over time in order for species to hunt food , hide and conserve energy

Question 22

theta waves

Answer 22

the typical brainwave pattern (medium frequency and mixed amplitude [some high, some low]) during the early stages of sleep

Question 23

ultradian rhythm

Answer 23

a biological rhythm that is shorter that 24 hours, such as NREM/REM sleep cycle