PSYC 1001 Chapter Notes -Electromyography, Human Brain, Oxycodone
Chapter 5 – Consciousness
•Consciousness – the awareness of internal and external stimuli
•Mind wandering – refers to people’s experience of task unrelated thoughts
Freud’s Levels of Awareness
•Conscious – consists of whatever one is aware of at a particular point in time
•Preconscious – contains material just beneath the surface of awareness that can easily be
•Unconscious – contains thoughts, memories, and desires that are well below the surface of
conscious awareness but that nonetheless exert great influence on behaviour
•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
oMeasures brain waves
oHuman brain activity is divided into 4 principal bands
Beta – awake/alert
Alpha – relaxed
Theta – light sleep
Delta – deep sleep
•Biological rhythms – periodic fluctuations in physiological functioning
oOrganisms have internal “biological clocks” that monitor the passage of time
•Circadian rhythms – the 24 hour biological cycles found in humans and other species
oParticularly influenced by sleep
oRhythms persist even when external cues are eliminated
oDaily exposure to light readjusts people’s biological clocks
•Electromyography (EMG) – records muscular activity and tension
•Electrooculograph (EOG) – records eye movements,
•1 – 7 minutes
•Breathing & heart rate slow; muscle tension & body temperature decline
•Alpha waves turn to theta waves
•Hypnic jerks – brief muscular contractions that occur as people fall asleep
•Sleep spindles (brief bursts of high-frequency waves) – appear against a background of
mixed EEG activity
Stage 3 & 4
•Slow wave sleep – high-amplitude, low frequency delta waves become prominent in EEG
•More relaxed – slower heart rate
•Then cycle reverses itself and the sleeper gradually moves back upward through the
Stage 5 – REM
•REM – rapid eye movements
•Deep sleep – hard to wake
•Irregular breathing & pulse rate
•Muscle tone is extremely relaxed
•High-frequency beta waves that resemble those observed when people are alert and
To summarize, REM sleep is a relatively deep stage of sleep marked by rapid eye
movements; high frequency, low-amplitude brain waves, and vivid dreaming.
The other 4 stages of sleep are considered Non-REM (NREM) sleep consisting of stages
1-4, which are marked by an absence of rapid eye movements, relatively little dreaming,
and varied EEG activity.
•People often repeat the sleep cycle about 4 times. As the cycle continues, the REM periods get
longer, and the NREM periods get shorter.
Sleep and the Brain
•Ascending reticular activating system (ARAS) – consists of the afferent fibres running through
the reticular formation that influence physiological arousal.
oInvolved in the regulation of sleeping and waking
Sleep Disorders and Problems
•Insomnia – chronic problems in getting adequate sleep
•Narcolepsy – a disease marked by sudden and irresistible onsets of sleep during normal waking
•Sleep apnea – frequent, reflexive gasping for air that awakens a person and disrupts sleep
•Nightmares – anxiety-arousing dreams that lead to awakening, usually from REM sleep
•Night terrors – abrupt awakenings from NREM sleep, accompanied by intense autonomic
arousal and feelings of panic
•Somnambulism (sleepwalking) – occurs when a person arises and wanders about while
•REM sleep behaviour disorder (RBD) – marked by potentially troublesome dream enactments
during REM periods
•Tend to unfold in familiar settings with a cast of characters dominated by family, friends, &
•Everyone experiences dreams from a first-person perspective
Theories of Dreaming
•Wish fulfillment (Sigmund Freud) – thought that people fulfill ungratified needs from
waking hours through wishful thinking in dreams.
oEx: an unsuccessful person might dream about great accomplishments
oCritic - Wish-fulfilling quality of dreams may not be readily apparent because the
true meaning of dreams may be disguised.
•Cognitive, Problem-solving view (Rosalind Cartwright) – proposed that dreams provide
an opportunity to work through everyday problems.
oThere is a considerable continuity between waking and sleeping thought.
oDreams allow people to engage in creative thinking about problems because
dreams are not restrained by logic or realism.
oResearch shows that sleep can enhance learning
oCritic – just because people dream about problems from their waking life doesn’t
mean they are dreaming up solutions.
•Activation-synthesis model (J. Allan Hobson & Robert McCarley) – dreams are simply
the by-product of bursts of activity emanating from subcortical areas in the brain.
oDreams are side effects of the neural activation that produces “wide-awake” brain
waves during REM sleep.
oDreams are just physiological response, our nerves are impulsive;
oCritic – the model can’t accommodate the fact that dreaming occurs outside of
REM sleep and that the contents of dreams are considerably more meaningful
than the model would predict.