Chapter 4 Definitions Flashcards
(23 cards)
alpha waves
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
amplitude
in terms of brainwaves, the height of the peaks and troughs of the curved graph that represents brain wave activity
beta waves
typical brainwave pattern (high frequency (fast) and low amplitude (small)) during normal waking consciousness, associated with being alert, active, anxious and paying (selective) attention
cataplexy
the total relaxation of muscles to the point of paralysis when in REM sleep.
also known as muscle atonia
circadian rhythm
biological rhythms that occur approximately once every 24 hours, for example the sleep-wake cycle and body temperature
deep sleep
collectively stage 3 and 4 NREM sleep
delta waves
the typical brainwave pattern (a steady pattern of low frequency (slow) and high amplitude (large)) associated with NREM deep sleep.
frequency
in terms of brainwaves, the number of brainwaves per second
hypnogogic (hypnic) jerks
involuntary muscle twitches that causes us to jolt are common; usually experienced in Stage 1 NREM sleep (part of hypnogogic state)
hypnogogic state
the relaxed state that occurs during the transition from being awake to being asleep, considered to be part of Stage 1 sleep
hypnopompic state
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
K-complexes
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)
muscle atonia
the total relaxation of muscles to the point of paralysis when in REM sleep.
Also known a cataplaxy
non-rapid eye movement (NREM)
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
rapid eye movement (REM)
one of two phase (REM and NREM) of sleep, characterised by rapid eye movement
restorative (restore and recover) theories of sleep
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
sawtooth waves
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
sleep spindles
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
slow wave sleep
collectively stage 3 and stage 4 NREM sleep
somnambulism
sleep walking
survival (adaptive and evolutionary) theories of sleep
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
theta waves
the typical brainwave pattern (medium frequency and mixed amplitude [some high, some low]) during the early stages of sleep
ultradian rhythm
a biological rhythm that is shorter that 24 hours, such as NREM/REM sleep cycle
