Chapters 4, 5, & 6

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