Chapter Five - Consciousness Flashcards
What is consciousness?
the subjective experience of the world, resulting from brain activity
What are variations of the normal conscious experience?
- sleep/wake cycles
- automatic tasks: done without awareness
- controlled processing: conscious awareness
Persistent Vegetative State
- full coma lasting over a month
- loss of almost all cognitive function
- lower level brain functions only (ex. breathing)
- no recovery possible
Minimally Conscious State
- deliberate movement and communication are possible
- some improvement possible
Brain Death
no brain activity
Locked-In Syndrome
- normal activity in cortex, inactivation of part of brain stem
- higher level processing intact, total awareness yet unable to communicate
- damage: motor control areas in brain stem
- result: paralysis of all muscles, except possible eyelids
- -> “Ghost Boy”
Could someone in a coma be aware?
depends on remaining brain activity
Imaging Studies in Coma Patients
- told to visualize playing tennis or walking through rooms of a house
- fMRI scans during instruction to determine activity in brain compared to non-coma patients
- -> Mont, et al (2010): pts able to respond through communication scans
What is the corpus callosum?
connecting fibers between halves of brain
-help coordinate walking, make right/left side work together
Visual System Organization
- both eyes see same thing
- everything in left visual field ends up in right occipital cortex/vice versa
- info shared between both sides (unless corpus callosum is gone)
Left Hemisphere vs. Right Hemisphere
Left: -access to language (Broca's/Wernicke's) -conscious -sequential Right: -better with spatial relationships -face processing -emotional processing
What part of the brain is the interpreter?
- left hemisphere comes up with explanations for behavior in right hemisphere
- right hemisphere simply “experiences” the world
What is the minimum amount of sleep we need?
4.5 hours
What are microsleeps?
falling asleep for a few seconds without realizing it
What happens when we don’t get enough sleep?
- deficits in mental performance
- lack of sleep –> accidents
- poor decision making/more impulsivity
- decrease in activity in frontal lobe
- increase in weight/crave fatty foods - impacts mood/anxiety
- amydala is more active - cognitive/memory deficits
- sleep debt
- lack of sleep builds up –> increased lapses of attention
What are negative health consequences of not getting enough sleep?
- obesity
- type 2 diabetes
- cancer
- increased inflammation –> cardiovascular disease
- suppressed immune system - function better while we sleep
- sleep debt
What is the interpreter?
a term specific to the left hemisphere; refers to the left hemisphere’s attempts to make sense of actions/ongoing events
What is subliminal perception?
the processing of information by sensory systems without conscious awareness
what are circadian rhythms?
the regulation of biological cycles into regular patterns
What is REM sleep?
the stage of sleep marked by rapid eye movements, dreaming, and paralysis of motor systems
What is insomnia?
a disorder characterized by an difficulty getting or staying asleep
What is obstructive sleep apnea?
a disorder in which a person, while asleep, stops breathing because his/her throat closes; the condition results in frequent awakenings during the night
-in non-REM sleep
What is narcolepsy?
a sleep disorder in which people experience excessive sleepiness during normal waking hours, sometimes going limp and collapsing (cataplexy)
-rapid REM onset (5 min): something wrong with restricting REM to sleep only
what is manifest content?
according to Freud: the plot of a dream/the way a dream is remembered
what is latent content?
according to Freud: what a dream symbolizes; the material that is disguised in a dream to protect the dreamer from confronting a conflict directly
what is the evolved threat-rehearsal theory?
the idea that dreams sometimes stimulate threatening events so that people can rehearse strategies for coping
What is hypnosis?
a social interaction during which a person, responding to suggestions, experiences changes in memory, perception, and/or voluntary action
what is meditation?
a mental procedure that focuses attention on an external object or on a sense of awareness
results of imaging studies with coma patients
told to visualize playing tennis OR walking through a house
fMRI scans during instruction were given to determine brain activity of coma patients compared to non-coma patients
results: same regions were activated (however doesn’t prove awareness)
what is subjective experience?
?
controlled vs automatic tasks
controlled: conscious awareness (ex. driving a city at rush hour)
automatic: done without awareness (ex. driving a familiar route)
Joe and the “interpreter”
?
flowerpot technique
method to selectively limit REM sleep in mice - placing them on a pedestal over water so that if they fell into REM sleep they would be quickly awakened
REM Pressure
increased attempts to enter REM during deprivation
REM Rebound
increased #/ intensity of REM episodes after deprivation
Peter Tripp vs. Randy Gardner
Tripp: 45 yr old radio show host went 10 days no sleep –> hallucinated, unable to function
Gardner: high school student wanted to make world record for most amount of no sleep, went 11 days –> no big consequences
Difference: drugs vs. sleep lab (controlled setting)
Familial Autosomal Insomnia
stop sleeping in middle age, just can’t sleep
–>usually die in 1.5 years
Activation Synthesis
dreams are a by-product of random brain activity –> brain synthesizes activity with memories (creates a story)
emotion centers = active: intense emotions
prefrontal cortex = inactive: acceptance of illogical events
REM vs. Non-REM dreams
REM: affect brain structures for motivation, emotion, reward, vision –> all active, frontal cortex is not (bizarre, intense emotions, imagery, acceptance of illogical events)
Non-REM: deactivation of many brain structures (dull dreams)
Freudian View
emphasis on subconscious entertaining our wishes
manifest content: the plot of the dream, the way the dream is remembered
latent content: what a dream symbolizes, the material that is disguised in a dream to protect the dreams from confronting direct reality
*no scientific evidence (not a theory)
Glial cell functions during sleep
shrink so toxins can flush out
Facilitation of Learning: Non-REM vs. REM tasks/types of learning
Non-REM: spatial learning, simple/memorization
REM: complex/conceptual learning
–> students spend more time in REM sleep during exam periods
Somnambulism: Case of Mr. A and sleepwalking violence
sleepwalking
- happens in stages 2-3 (deep sleep)
- inability to recognize people
Mr. A
- lots of work stress, sleep deprivation, caffeine
- wife asked him to fix pool filter
- wife found stabbed 44 times and in pool
- -> Mr. A unable to recognize wife in sleepwalk
- found guilty
REM Behavior Disorder
acting out dreams due to damage to areas in brain stem that normally inhibits muscles during REM sleep
cataplexy
sudden loss of muscle tone, often triggered by emotions
brain activity and consciousness
different type of sensory information are processed by different brain areas: the particular type of neural activity determines the particular type of awareness
findings from split brain studies
- left hemisphere controls speech (can only talk about image on right side)
right hemisphere is mute (unable to talk about image on left)
2.
left hemisphere is not good with spatial relationships (cannot put blocks in a square shape with right hand)
right hemisphere is better with spatial relationships (cannot talk about an image but can pick that object up with left hand)
Stages of Sleep
Stage One: light sleep, easily aroused
Stage Two: breathing regulated, less sensitive to outside, K-complexes (occasional bursts of activity)
Stage Three/Four: large regular delta waves = slow wave sleep, hard to wake, disoriented
REM Sleep: beta waves like alert/awake mind, rapid eye movements, brain active-body paralyzed, dreams
Sleep as Adaptive Behavior
restorative theory: allows brain to rest/repair
circadian rhythm theory: sleep evolved to keep animals quiet/inactive during times of day during greatest danger
what is flow?
optimal experience in that the activity is completely absorbing and completely satisfying
what is atonia?
lack of muscle tone, gradually decreases during sleep
