Download Sleeping - Psychology

Introduction to Course
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Web Site:
www.psy.cmu.edu/~kotovsky/85102/home.php
Instructor
TA’s
Major Instructional Strategy and Goals
– Depth, higher educ., focus, purpose(s)
Major Activities: highly varied
Methodology
Questions
For the first recitation, bring a significant or “big” and real question
about psychology, one that psychology might (or perhaps might
not) have an answer to, and be prepared to discuss it a bit and also
turn it in to your TA. It should be something that you are genuinely
interested in and curious about. Save a copy for yourself—it might
come in handy when generating a paper topic!
Question Examples
(Including one author’s attempt to answer)
David Brook’s Ex. (NYT 8/24/10)- What are our thinking weaknesses?
“For example, Charlie Munger of Berkshire Hathaway once described “The
Psychology of Human Misjudgment.” He and others list our natural weaknesses:
-We have confirmation bias; we pick out evidence that supports our views.
-We are cognitive misers; we try to think as little as possible.
-We are herd thinkers and conform our perceptions to fit in with the group.
To use a fancy word, there’s a metacognition deficit. Very few in public life habitually
step back and think about the weakness in their own thinking and what they should
do to compensate.
Brooks also more recently wrote about what makes true genius:
the ability to hold two contradictory ideas in your head simultaneously; a kind of self
examining or self-challenging stance we might think of as a thinking strength.
Antietam: Historic battlefield—leads to a question….Why are we so
willing to kill each other?
Methodology: Some Basic Issues
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Why Psychology? (vs. other sources of wisdom)
Focus on actual data
Observation vs. experimentation
Independent and dependent variables
Experimental control-getting rid of spurious
variables
• Correlation and causation
• “Unusualness” of a result: statistics
• Distributions (the statistical nature of our data)
Basic Methodology
• Observational vs. Experimental studies
Causation vs. Correlation
(storks, scz, food)
Experimentation
Independent vs. Dependent Variables
Experimental “Control” & Confounds
(Hawthorne)
Making Observations
• Scientific observations often begin with a
question or hypothesis.
• The hypothesis must be testable.
• This calls for an operational definition of key
terms to specify the study’s dependent
variable.
• Data must also be systematically collected.
• Researchers ignore anecdotal evidence.
Defining the Sample
• Based on observations of a sample,
psychologists want to draw conclusions
about a broad population.
• Random sampling
• All members of the population have an
equal chance of being picked to
participate.
• Researchers also use other procedures,
including stratified sampling and case
The Power of Experiments
• The two groups must be matched at the
outset of the experiment.
• To ensure matching groups,
researchers use:
• random assignment (ex. Clinical trials)
• within-subject comparison.
• taking precautions to address problems created
by the sequence of conditions
The Control Condition
Assessing External Validity
• Researchers want their study to mirror
circumstances of the broader world.
• external validity
• External validity depends on many
factors.
• The study should not change behaviors the
researchers hope to understand.
Assessing External Validity
• One concern here involves the study’s
possible demand characteristics:
• Cues to participants/experiments about
how they’re supposed to behave
(Rosenthal)
• One way of avoiding this problem is to
use a double-blind design.
Measurement
• The Description of Data
– Central tendency
• Mean, median, mode
– Variability
• Variance
• Standard deviation
– Correlation & significance level
Measurement
T
H
HT
TT
T = tails
H = heads
TH
HH
Correlation Coefficients (0 – 1)
Sleeping
The ignored behavior!
Defining/describing sleep
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Decreased awareness & interaction with world
Decreased motility & muscular activity
Characteristic posture
Partial or total decrement in voluntary
consciously directed behavior
• Decreased forebrain activity & cortical input
from lower centers
Sleep as a behavior
• Quietude
• Life span decrease
• Brain activity/EEG & reactivity
Theories of sleeping
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Motivation
Energy conservation
Restorative
Memory consolidation & Learning
Adaptive
Brain Control
Hypothalamus: Rostral/Caudal sleep areas
– Rostral (stimulate --> sleep, extirpate --> wake)
– Caudal (stimulate --> wake, extirpate --> sleep)
– Reticular activating system & monitoring
– Hypothalamus’ superchiasmatic nucleuspineal
glandmelatonin sleep. (light supresses Mel.)
– Kleitman in a cave!
Arguments for
Necessity/Functionality of sleep!
– Regularity
– Motivation/crummy feelings
– Health involvement
-Fatal Familial Insomnia (30+ families/thalamic/death)
-Some linkage to other disorders (depression, cold susceptibility)
(although sleep deprivation helps in depression via activation of serotonin
receptors)
– Hallucination argument
– REM recovery
– Restorative: increase in SWS in sleep-deprived & athletes,
increase anabolic/decrease catabolic activity
– Memory consolidation REM block->poor memory function
– Some rat studies show immune system effectsdeath
Arguments Against Necessity
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Deprivation/human & animal
Exceptional sleepers
Hallucination explanation
Dement study 11 days deprv. Then 16 & 8 hours
REM recovery: limited
Programmatic reduction-->1-2 hr. decline
– 1/2 hr per 2 weeks->4.5-5.5 ok
– One year later slept 1 to 2.5 less!
• Cats in a puddle!
Conclusions
Adaptive theory seems to win!
– The function of sleep is sleep!
– Ungulates sleep much less than meat eaters
• Five hours or less (opossums 19-20 hours)
• Frogs don’t sleep. Dolphins sleep ½ brain at a time!
• Small/defensless animals sleep much more
– Accounts for life span decrease as well
– But still a bit of an open question
One Last Theory About Sleep
“Basic Satisfaction” Theory
– https://www.youtube.com/watch?v=MUw3s4evhTE
Dreaming: What & Why?
Multiple perspectives and much
speculation!
Outline
• Dream behavior
• Theories of Dreaming
• Conclusions
– What can we learn from our dreams?
– Are they meaningful? True / predictive?
Dream behavior & description
• Within sleep
• Amount
• Brainwave activity & bodily quietude:the
paradox
• REM
Dreams & REM sleep
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Aserinsky-REM
Dement & Kleitman-Stages
REM amount & periodicity
Brainstem cholinergic & adrenergic
promoting & inhibiting areas for REM
• A regular activity rooted in the brain
Some Questions:
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Are Dreams meaningful--what do they mean?
Are the predictive or “true”?
How do they differ from other states?
What is their function do they even have one?
Are they primarily brain functions or mind
functions?
Outline
• Characteristics and Descriptions
• Theories of Dreaming
• Conclusions
– What can we learn from our dreams?
• Are they meaningful? True / predictive?
Theories of Dreaming
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Dreams as meaningful events:
Freud (& Jung)
Aserinsky, Dement & Kleitman implications
Hall/Cartright
Dreams as random activity (Hobson +)
Synthesis (perhaps)
Psychoanalytic Theory
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Mental conflict
Unconscious motivations
Two forces: impulses & defenses
Dreams as a release
Dreamwork and its results
– Latent dream
– Manifest dream
– Remembered dream
Dreamwork and forgetting as protective mechanisms
Poetzel Effect
Freud & Neuroimaging
• Michael Anderson- Validates Repression: Forebrain active in
inhibiting hippocampus on repressed items
• Allen Braun: Limbic system-emotion active during REM
• Prefrontal cortex (working mem. Attention, logic & selfmonitoring) inactive during REM
• Above consistent with dream bizarreness & emotional
disinhibition/wish fulfillment
• Visual cortex inactive but higher visual areas active so we see
w.o. visual input- one of the amazing things about
dreaming!
Freud & Neuroimaging (Mark Solms)
Injured Pons vs. injured Forebrain
-Pons-disrupts REM but dreaming goes on.
-Forebrain-lose dreaming but REM goes on.
-Also, some dreaming outside of REM
Role of Motivation (in addition to emotional areas)
-Prefrontal leukotomy (white matter in ventro-medial
forebrain area) decreases dopamine release. It’s a
motivational area “seeking” behavior.
-Hartmann: administering dopamine supercharges
dreaming! Supportive (in a general way) of Freudian
link between motiv. & dreaming.
Variations on Psychoanalytic
Explanation + Challenges
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Aserinsky, Dement & Kleitman: REM & implications
Hall and Cartwright: Dream Series
Challenging Views
Dreams as random activity (Hobson +)
Synthesis (perhaps) as Hobson accepted imaging
results
Other Neuroscience Views
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Crick: Purge extraneous connections
Evans: Sorting function on day’s events
Winson: Sorting for survival
Wilson: Rat Dream article- maze
learning during dreams
• Hobson: random activity & activationsynthesis hypothesis
Hobson: Dream Transformations
From:
To: Inanimate
Animate
Character
Inanimate Animate Character
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Dream Characteristics
Lack of active volition
Absence of ongoing reflective judgment
Limited to phenomena of the immediate present
Diffuse cognitive slippage--dreamlike confusiontransformations of perception, thought, memory, emotion,
relationships, etc.
Gaps in experience: 20%
Confusion of thought & irrational intuitions: 41%
Problems in sustained attention: 5%
Memory deficiencies within the dream: 15%
Overall, even 51% of "clearest dreams" had clouding of cs.
--Usually not radical (scz, psychedelic) but rather more like that of waking life
Can even have hallucinations or psychedelic exper. in
dreams (as in waking life!) ex. flying 4%, bizarre figures,4%,
changed identity 3%, LSD-like transformations of
vision 13%. Mostly visual 47%. Somatic 10%, audit. 14%.
Conclusions
• Can we obtain meaningful insights
about ourselves through our dreams?
• What can we learn from our dreams?
• Are they meaningful? true /
predictive/useful?
• Dream problem-solving (Lowie, Kekule)!