Lecture 4 Flashcards
what is consciousness?
- moment to moment awareness of ourselves and environment
- others cannot directly know our reality
- dynamic is ever-changing
- self reflective - mind is aware of its own consciousness
what is problem of other minds?
fundamental difficulty we have in perceiving the consciousness of others
how do we measure consciousness?
- self reports: direct but not verifiable
- physiological: are objective but cannot indicate what person is experiencing subjectively (ex. EEG)
- behavioural: performance on tasks, need to infer state of mind
what was Benjamin Libet’s experiment?
participant was asked to move fingers at will while watching a dot move around the face of a clock to mark the moment at which the action was consciously willed
what are the 3 levels of psychodynamic views?
- conscious: mental vents we are currently aware of (ex. reading this slide)
- preconscious: outside of current awareness; easily recalled ( ex. what you had for dinner last night)
- unconscious: not brought into conscious awareness under ordinary circumstances (ex. unacceptable urges; traumatic memories tied to anxiety; pain)
what is controlled and automatic processing?
controlled: effortful- voluntary use of attention; conscious effort, difficult or new tasks, slower but more flexible than automatic
automatic: littler or no conscious processing; routine; well- learned, fast but can inhibit finding ‘new’ solutions, facilitates ‘divided atention’
how many things can you do at once?
- we can ‘divide’ attention - otherwise every action would require full attention
- is adaptive but has limits - difficult if tasks require similar resources, impact others (ex. using cell phone while driving)
what is emotional unconscious?
unconscious processes influence emotions and motivations - are influenced by events we are unaware of (classical conditions), mood can be affected by positive or negative words subliminally presented - priming
what is the molecular mind?
- mind consists of separate but interacting info processing modules: sensations, perception, memory, problem-solving, emotion, process info is parallel
- experience of consciousness is integrated output of modules
what is the circadian rhythm?
refers to the body’s natural 24 hr cycle, roughly matched to the day/night cycle of light and dark
what changes during the 24 hours?
- body temp
- arousal/energy
- mental sharpness
Describe the circadian rhythm‘s
- regulated by suprachiasmathic nuclei (SCN)
- SCN neurons link to pineal gland which secretes melatonin
- SCN neurons are sensitive to light only around “dawn” and “dusk”
- Neurons in SCN are active during daytime (inhibits melatonin secretion & raises body temperature and alertness)
- SCN neurons are inactive at night (allows melatonin secretion to increase & melatonin promotemelatonin promotes relaxation and sleepiness)
what disrupts the circadian rhythm?
- jet lag
- shift work
- changing to daylight savings
- seasonal affect disorder (SAD)
what are the stages of sleep?
-cycle through stages roughly every 90 minutes
-BRAC: Basic rest activity cycle
-Brain activity, other physiological responses change
-beta waves occur when awake and alert (15-30cps)
-alpha waves occur when relaxed and drowsy (8-12cps)
stage 1: light sleep, theta waves (3.5-7.5cps), lasts few minutes, may experience body jerks
stage 2: sleep deepens- muscles are more relaxed-harder to awaken, sleep spindles (1-2 second bursts of rapid brain activity)
stage 3: sleep deepens, regular appearance of delta waves (0.5-2cps)
stage 4: sleep deepens, delta waves dominate pattern, stage 4 & stage 3 - together called slow wave sleep
-after stage 4 period, go back through earlier stages -stage 3, then 2 but not 1, instead a new stage appears
-REM sleep: rapid eye movements, High arousal, frequent dreaming
what happens during REM sleep?
- heart rate rises and breathing becomes rapid
- “sleep paralysis” occurs when the brain stem blocks the motor cortex’s messages and the muscles don’t move. this is sometimes known as “paradoxical sleep”; The brain is active but the body is in mobile
- genitals are aroused (not by dreams) and stay this way after REM is over
- REM periods become longer as the night progresses
what is sleep regulated by?
- falling asleep: regulated by basal forebrain & regions of brain stem
- REM sleep: regulated by brainstem (reticular formation), limbic system activity increases, Association areas near visual cortex active, motor cortex active but signals blocked, decreased activity in prefrontal cortex
Why do we sleep?
- restoration model: sleep recharges bodies, sleep allows recovery from mental and physical fatigue
- evidence is mildly supporting: sleep about 10 minutes longer on days we exercise, adenosine (cellular waste product) may play a role in decreasing alertness
what happens when we have sleep deprivation?
-across our lifetime we get about 1 hour of sleep for every 2 awake
-memories deteriorate
unless sleep occurs
-REM sleep deprivation has the most detrimental effects, followed by slow wave sleep (stage3&4)
why do we sleep ?- theories and models
- evolutionary/circadian models: is adaptive, evolved sleep-wake pattern that increased chances of survival (reduces predation & optimizes food acquisition/per calorie expended), mechanism for conserving energy (metabolic rate 10 to 25% slower during sleep)
- restoration and evolutionary theories: contribute to 2 factor model asleep
what are two common sleep disorders?
- insomnia:
- chronic difficulty and falling asleep, staying asleep or experiencing restful sleep
- most common sleep disorder (10 to 40% of population)
- North Americans sleep less than others and less than they used to perhaps because of the use of light bulbs and/or screen time
- pseudoinsomniacs:
- complain of insomnia, but sleep normally
- individuals truly believe they have insomnia
- research in sleep labs show most sleep normally
what are causes and treatments of insomnia?
- multiple causes: biological, psychological, environmental
- several treatments: stimulus control (based on learning principles, associate stimuli in sleep environment only with sleep)
what is narcolepsy?
-Extreme daytime sleepiness and sudden uncontrollable sleep attacks
what is cataplexy?
sudden loss of muscle tone
what is REM-sleep behaviour disorder?
-loss of muscle tone that causes REM- sleep paralysis is absent
• sleeper may act out dreams: kick, punch, move wildly
• many RBD patients have injured self or sleep partner
