key terms

Question 1

stage 1 of sleep

Answer 1

stage 1: .5 - 7.5 Hz
- transition between wakefulness and sleep
- short

Question 2

stage 2 of sleep

Answer 2

stage 2:
- irregular activity and sleep spindles
- longest

Question 3

stage 3 of sleep

Answer 3

• high ampitude low frequency of delta activity <3Hz
• synchronised regular waves - reflect synchrony and coordination in activity of neurons in underlying brain areas
• slowing down of brain activity and bodily functions e.g. heart rate and temperature

Question 4

REM

Answer 4

• increased brain activity and asynchrony in the brain waves
• muscle atonia - not producing action potentials
• rapid eye movement
• deep sleep in terms of muscle activity but light sleep in terms of brain activity - paradoxical sleep
• facial switches, erections, vaginal secretions, dreams

Question 5

activation-synthesis-hypothesis

Answer 5

HOBSON 2004:
BOTTOM-UP

• brain stem is activated during REM and sends signals to the cortex
• THIS creates images with actions and emotions fro memory
• the frontal cortex is less activated during dreaming –> this explains why dreams are illogical and follow no sequence of events

Question 6

coping hypothesis

Answer 6

VALLI 2009

dreams = biologically adaptive > to enhanced coping strategies

• top-down view on dreams
• dream about events they find threatening
• problems solving occurs during sleep - ‘sleep on it’

Question 7

Adenosine

Answer 7

• accumulates during day after prolonged wakeness –> promotes sleep

caffeine antagonises these effects

Question 8

reticular activating system

RAS

Answer 8

• nuclei in brainstem that extend to forebrain to promote arousal

Question 9

orexin/hypocretin

Answer 9

peptide released from lateral hypothalamus
- maintains wakefulness
- implicated in narcolepsy

Question 10

zeitgebers

Answer 10

cues that serve to set our biological clock

e.g. light

Question 11

chronotypes

Answer 11

different patterns of wakefull to alertness - inudviudal differences

Question 12

suprachiasmatic nucleus

Answer 12

• the clock
• SCN

lesions here disrupt circadian rhythms

neurones here are more active during light than dark

–> transplants of SCN into donor = recepient follow donor rhythm

Question 13

how does light reach the SCN

Answer 13

through the retinohypothalamic tract

special ganglion cells PRGCs

Question 14

PRGC

Answer 14

Special ganglion cell with own photopigment - melanopsin - that responds directly to light - no rods/cones required