chapters 4, 5, & 6
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Chapters 4, 5, & 6. AP Prep Review. Sensation/Perception. Sensation/Perception. Absolute Threshold Minimal amount for a stimulus to be detected Just Noticeable Difference (difference threshold) Minimum amount of distance between two stimuli that can be detected - PowerPoint PPT PresentationTRANSCRIPT
Chapters 4, 5, & 6AP Prep Review
Sensation/Perception
Sensation/Perception
Absolute Threshold Minimal amount for a stimulus to be detected
Just Noticeable Difference (difference threshold) Minimum amount of distance between two stimuli
that can be detected Example: playing pairs of tones of varying volumes
Weber’s Law Size of JND is in constant proportion of the size of
the initial stimulus weight lifting 1/30
Signal-Detection Theory
Involves decision processes as well as sensory processes Hit – signal present, person reports sensing it Miss – signal present, participant did not sense
it False Alarm – signal absent, participant reports
sensing it Correct Rejection – signal absent, participant
did not report sensing it
Transduction
Converted from outward stimulus to the electorchemical signal
The Eye Lens
Focuses light rays on retina Pupil
Light goes through (black part) Retina
Absorbs light, processes images, sends visual info to the brain Rods
Night vision & peripheral vision Cones
Day time vision & color Fovea
Tiny spot in the center of the retina, cones only, visual activity greatest at these spots
Parallel Processing
Simultaneous extraction of different kinds of info from the same input Example: Parvocellular channel handles color
and perception, and magnocellular handles brightness
Color Theory
Young-Helmholtz or Trichromatic Theory The eye has 3 receptors with different sensitivity to different
light waves Blue, red, green
Opponent Process Theory Color perception depends on receptors that make
antagonistic responses to three pairs of colors Red v. Green Yellow v. Blue Black v. White
After image Stair at a red dot, turn to white paper is green
Feature Analysis
Bottom-up processing Individual elements to whole
Top-down processing Whole to individual People perceive the whole world before seeing
the individual letters
Phi Phenomenon
Illusion of movement created by presenting visual stimuli in rapid succession
Separate still pictures projected rapidly one after the other, leads you to believe motion is occurring
Max Wertheimer
Formulating Perception
Distal Stimuli Stimuli that lie in the distance (exists in
environment) Proximal Stimuli
Stimulus energies that impinge directly on sensory receptors (on the retina)
Hearing
Cochlea Fluid filled coiled tunnel contains the receptors
for hearing Basilar membrane
Runs length of spiraled cochlea holding auditory receptors Auditory receptors = hair cells
Theories of Hearing
Place Theory Hermann von Helmholtz Perception of pitch corresponds to the vibration of
different portions, or places, along basilar membrane Different hairs set up by different sounds (wrong)
Frequency Theory Perception of pitch corresponds to the rate, or
frequency at which the entire basilar membrane vibrates
The whole membrane vibrates in unison in response to sound
Senses
Olfactory - smell Habituation – we become accustomed to stimulus
notice it less over time Dishabituation – small change in stimulus causes to
notice it again Gustation – taste Tactile – touch Law of Pragnanz – we see things in its simplest form
Gate-Control Theory
Pain can only be felt if it can pass through a gate in the spinal cord Louisville’s Kevin Ware
Consciousness
Consciousness
Subliminal perception Preconscious processing Presented with a stimulus so rapidly we do not detect
Conscious Pre (sub) conscious Unconscious Repression – forgettabout it Freudian slips - oops!
Sleep
Melatonin – chemical associated with sleep Circadian Rhythm
24 hour biological cycle found in humans We fall asleep at certain points of the day Sleep (body temp drops) awake (body temp
rises) Occurs even without time cues
Electroencephalograph (EEG)
Beta 13 – 24 cps – normal waking thought, alert Dreaming
Alpha 8 – 12 cps – deep relaxation, blank mind, meditation
Theta 4 – 7 cps – light sleep
Delta Less then 4 cps – deep sleep Stage 4
Dreaming
REM Stage 5 Paradoxical sleep – brain waves resemble when we are awake
even though we are in a deep sleep Manifest – storyline of dream Latent – symbols underlying meaning
NREM Stages 1 – 4
Sleep Spindles Stage 2 Brief bursts of higher-frequency brain waves
Sleep Disorders
Narcolepsy Sleep apnea Nightmares v. Night terrors Narcolepsy Sleep walking (somnambulism) Insomnia
Activation-synthesis hypothesis of dream
Dreams are a product of our awareness of neural activity due to sensory input while we are sleeping. Neural repair, consolidation of memories, and protein synthesis seem to occur during dreams
Dreaming
Manifest content – Story line of dream Latent content – underlying meaning
Learning
Classical Conditioning
Ivan Pavlov, John Watson & Rosalie Rayner UCS – stimulus creates a unconditioned response
without previous conditioning UCR – unlearned reaction to an unconditioned
stimulus occurs without previous conditioning CS – previously neutral stimulus that has through
conditioning acquired ability to create a CR CR – Learned reaction
Classical Conditioning
Acquisition – initial stage of learning, pairing items
Discrimination – Do not respond to new stimuli as did with the old
Generalization – responds to similar stimuli Extinction – gradual weakening/disappearance
of CR Spontaneous Recovery – reappearance of
extinguished response
Classical Conditioning
Second Order Conditioning Previous CS now used as UCS
Higher Order Conditioning a conditioned stimulus functions as if it were
an unconditioned stimulus New conditioned responses are built on the
foundation of already established conditioned response (Red light paired with bell)
Garcia Effect
Conditioned taste aversion (CTA) Garcia Effect Animals eat food and as a result become
nauseated by drug/radiation will not eat that food again
Highly resistant to extinction
Instrumental Conditioning
(Operant Conditioning) Edward Thorndike
Law of Effect – behavior is more likely to recur if reinforced
Cat and the puzzle box
Instrumental Conditioning
(Operant Conditioning) B.F. Skinner
Shaping – rat near the lever, touching lever, pressing lever Differential reinforcement of successive approximations –
only rewarded for pushing the lever Primary (natural) reinforcement – Events that are inherently
reinforce behaviors because they satisfy biological needs Food, sex, warmth, water
Secondary Reinforcement - Events that acquire reinforcing qualities by being associated with primary reinforcement Examples: Money, good grades, attention, flattery, praise,
cars, jewelry
ShapingTwo Kinds of Stimuli
Positive NegativePositive Reinforcement• Add something that
follows the stimulus• Appetitive (good).
Positive Punishment• Add an aversive (bad)
that follows the stimulus
• Spanking
Negative Punishment• Removal of an
appetitive• Grounded• Timeout
Negative Reinforcement• Removal of an
aversive• Seatbelt noise • Doing chores
Four Basic Methods of Reinforcement
Ratio - # Interval - Time
FixedSchedules
(Regular)
Variable
Schedules
(Irregular)
Reinforced after a fixed number of responses
• Paid for every 10 pairs of jeans I sell at the GAP.
• Two yellow cards = ejected from the volleyball game.
Reinforcement after varying number of responses
• Slot machines• Door to door sales
Reinforcement of first response after a fixed amount of time ahs passed.
• Pick up check every two weeks.
• Cram for a test, but study a lot less afterwards.
Reinforcement of first response after varying amounts of time.
• Surprise quiz in class.• Dialing a friend on the phone
and getting a busy signal.
More Terms . . .
Token Economy Artificial economy based on . . . (you guessed
it) tokens Tokens act as secondary reinforcer and can be
used for purchasing primary reinforcer (food). Learned Helplessness
Consistent effort fails to bring reward Example: Study for test get bad grade
Social Learning (Vicarious Learning)
Bobo Doll Learning from watching others
Cognitive Processes
Edward Tolman Trained rats to run maze to obtain food
(reward) Cognitive Map
Tolman concluded that rats had a “cognitive map” of where the food was and that it was “over there” (not just a series of right-left responses
Latent Learning
Learning that is not expressed until needed Rats in Tolman’s experiment