exam 3 Flashcards
What is Consciousness?
• Awareness of internal and external stimuli.
• Almost every human behaviour comes from a mixture of conscious and unconscious processing.
- ex: digestive system
The Nature of Consciousness: Variations in Awareness and Control
Awareness of internal and external stimuli
Different levels of awareness
Attention and consciousness are closely related but you can have one without the other. Example: Mind wandering
James
stream of consciousness
Different Forms of Consciousness
occur spontaneously: daydreaming, drowsiness, dreaming
physiologically induced: hallucinations, orgasm, food or oxygen starvation
psychologically induced: sensory deprivation, hypnosis, meditation
Levels of Consciousness
Consciousness ranges in levels from minimal consciousness to full consciousness to self- consciousness.
full consciousness
self-consciousness
minimal consciousness
Full consciousness
Consciousness in which you know and are able to report your mental state
Self-consciousness
Distinct level of consciousness in which the person’s attention is drawn to the self as an object
Recognition of self in mirrors by humans and other animals
Minimal consciousness
Low-level kind of sensory awareness and responsiveness that occurs when the mind inputs sensations and may output behavior
More on Levels of Consciousness
-Looking at the link: EEG, fMRI, PET scans.
• Hypnosis and anesthesia can teach us about
consciousness.
• Processes in the brain that create consciousness: sensory network and internal consciousness network exchanges information with the thalamus
-comas and brain death
comas
Brain damage. Lasts for a few days or weeks. May open the eyes but not be consciou
Brain death
axons are torn and cannot carry messages.
comas
Unconscious, unresponsive, unarousable (no sleep/wake cycle).
vegetative state
stupor
PVS
locked in syndrome
vegetative state
Unresponsive to psychological and physical stimuli, have a sleep/wake cycle, often eyes open.
stupor
Unresponsive but can be aroused briefly by pain.
PVS
persistive vegetative state
After 30 days, PVS
locked in syndrome
Awakens from coma and is completely conscious but paralyzed and can only blink.
Anesthesia
Used to be thought that ‘going under’ was like a sub going deeper into the ocean
• Problem: Seems like the path downward into unconsciousness is not the same as the pathway coming into consciousness
• Used to be thought that ‘old brain’ comes back before more complex functions
• Different brain patters with stages of anesth
Consciousness and Brain Act
• EEG – monitoring of brain electrical activity
• The electroencephalograph
• Brain waves
• Amplitude (height)
• Frequency (cycles per second) (= correlated)
• Beta (13–24 cps)= alertness/problem-solving
• Alpha (8–12 cps) = resting/relaxation
• Theta (4–7 cps) = low-alertness/sleep
• Delta (< 4 cps) =deep/dreamless sleep
Wandering Mind
• Our minds most often wander when we are engaged in automated, repetitive tasks or in difficult/complex tasks.
• We may be unaware of our minds wandering.
• Similar to under the influence of alcohol
• Effects of driving while ‘wandering’ and drinking while driving – dangerous!
The Default Network Activated During Daydreaming
• An fMRI scan shows that many areas, known as the default network, when mind wandering or daydreaming. More activity at rest than during attention- demanding tasks.
sleep
don’t know why all animals sleep
babies need more sleep
need less sleep as ppl get older
Biological Rhythms and Sleep
circadian rhythms
physiological pathway of the biological clock
melatonin and circadian rhythms
ignoring and realigning circadian rhythms
Physiological pathway of the biological clock
• Light levels > retina > suprachiasmatic nucleus of hypothalamus > pineal gland > secretion of melatonin
Circadian rhythms
– 24 hr. biological cycles
• Regulation of sleep/other body functions
Sleep as a State of Consciousness
When sleeping, are we fully unconscious and “dead to the world”?
Or is the window to consciousness open?
§ We move around in bed but don’t fall out.
§ We sometimes incorporate real- world noises into our dreams.
§ Some noises (our own baby’s cry) wake us more easily than others
How Do We Learn About Sleep and Dreams?
§ We can monitor EEG/brain waves and muscle movements during sleep.
§ We can expose the sleeping person to noise and words, and then examine the effects on the brain (waves) and mind (memory).
§ We can wake people and see which mental state (e.g. dreaming) goes with which brain/body state.
Measuring the Sleep and Waking Cycle
• Instruments:
• Electroencephalograph – brain electrical
activity
• Electromyograph – muscle activity
• Electrooculograph – eye movements
• Other bodily functions also observed
Cycling Through the Stages of Sleep
stages 1-4
stage 1
brief, transitional (1–7 min.)
• alpha > theta
• hypnic jerks
stage 2
sleep spindles and K-complexes (10–25 min.)
stages 3 & 4
slow-wave sleep (30 min.)
stage 5
REM, EEG similar to awake, vivid dreaming (initially a few minutes, progressively longer as cycle through the stages)
• Developmental and cultural differences in REM sleep
REM sleep
Fast brain wave activity: alpha/theta like awake state. Also beta waves.
• ‘Paradoxical sleep.’
• Breathing rapid/irregular.
• Needed for learning, but different kinds of sleep may relate to different kinds of learning
EEG Patterns during the Stages of Sleep
awake - beta waves
drowsy, relaxed - alpha waves
stage 2 sleep - sleep spindles, K complexes
stage 3/4 sleep
delta waves
REM sleep
fast, random
Age Trends
• 15-24 greatest sleep time
• 33-44 least (time stress)
• Newborns—sleep 6-8 times in 24hrs or 16-17 hours per day. In some cultures where babies are carried sleep less.
• Have only 2 types—REM and NREM and spend more time (50%) in REM than adults but not dreaming—brain connections
• Age; ethnicity
Sleep Over the Life Span
§ Shorter sleep cycles in infancy. Sleep 17 hours a day 50% REM § 90-minute cycle emerges by age 5
§ From childhood to late adulthood, total sleep time decreases §15-20 year olds sleep average of 8.5 hours aday and the elderly
average under 6 hours.
§ Time spent into stages 3 and 4 declines and by late adulthood we get little stage slow wave sleep.
Why Do We Sleep?
§ Protective role in human evolution
§ Brain restoration and repair of damaged neurons
§ Store and rebuild memories of day’s experiences
§ Promotes creative problem solving
§ Encourages growth through pituitary gland secretion of growth hormone
§ Memory consolidation–synaptic changes associated with recently stored
memories become durable and stable, causing memory to become more
reliable.
§ May also enhance problem-solving abiliti
The Neural and Evolutionary Bases of Sleep
• Brain structures:
• Ascending reticular activating system
• Pons, medulla, thalamus, hypothalamus, limbic system
• Neurotransmitters:
• Acetylcholine and serotonin
• Also norepinephrine, dopamine, and GAB
Sleep Needs and Deprivation
• Across our lifetime, we get about one hour of sleep for every two awake.
• Memories deteriorate unless sleep occurs.
• REM sleep deprivation has the most detrimental effects, followed by slow- wave sleep (stage 3).
The Effects of Sleep Deprivation
§ Fatigue
§Impairment of concentration,
creativity, communication
§Can lead to obesity, hypertension, suppressed immune system
§Can lead to irritability and slowed performance
§Affects attention, memory, reaction time, decision making, motor coordination, immune system, emotional regulation.
Doing Without: Sleep Deprivation
Complete deprivation – 3 or 4 daysmax
Partial deprivation or sleep restriction
-Impaired attention, reaction time, coordination, and decision making
-Accidents: Chernobyl, Exxon Valdez
Selective deprivation
-REM and slow-wave sleep: rebound effect
Sleep loss and health
sleep disorders
insomnia
sleep apnea
somnambulism
narcolepsy
sleep paralysis
night terrors