PSYC 1100 Exam 2

Split brain studies

- corpus callosum is severed - no communication between hemispheres

- left visual field to right hem (spatial abilities), right visual field to left hem (language)

- image on right goes to left hem, patient able to say what it is

- image on left goes to right hem, patient unable to say what it is

- however, left hand can pick out correct object

- when asked what it is, right hem still doesn't know and guesses incorrectly

Classical conditioning: US

- unconditioned stimulus

- input to a reflex

- ex. food

Classical conditioning: UR

- unconditioned response

- output of a reflex

- ex. salivation to food US

Classical conditioning: CS

- conditioned stimulus

- initially means nothing, but during learning process becomes associated with the US

- results in production of CR

- ex. bell

Classical conditioning: CR

- conditioned response

- response to CS, thing that is actually produced

- able to be measured for amplitude, probability, latency

- ex. salivation

Habituation

- decrease in response to a repeated stimulus with no actual effect

- ex. before we give the dog any food, we ring the bell a few times. The dog receives no reward, and eventually stops paying attention to the bell - it doesn't mean anything

- in other words, you get used to something that has no meaningful consequence

UR vs CR

- UR is a natural, unlearned behavior

- CR is learned, triggered behavior

Measures of a conditioned response: Amplitude

strength of CR ex. how much saliva

Measures of a conditioned response: Probability

how often CR occurs ex. 3 out of 10 trials

Measures of a conditioned response: Latency

time for CR to occur ex. how many seconds until heart rate increases

Acquisition

- period of learning when CS is paired with US

- more reinforcement makes CR stronger

Extinction

- extinguishing of CR until it goes away completely

- due to giving CS without US

Spontaneous recovery

- after 24 hours of rest following extinction, CR is recovered without any re-learning.

- not as strong as before

- extinction happens faster now

- eventually spontaneous recovery stops happening after many trials

Reacquisition

- after full extinction and no spontaneous recovery, dog can re-learn CR faster than the first time

Spontaneous recovery takeaways

- learning never truly goes away - even after extinction

- even after spontaneous recovery, re-learning happens quickly

How does spontaneous recovery work?

- with each reinforced trial, excitatory association is built up

- when it reaches maximum, acquisition phase is complete

- this is permanent!

- during extinction, separate inhibitory association is learned

- gets stronger with each extinction trial

- when it matches strength of excitatory, extinction occurs

- strength of CR = excitation - inhibition

- inhibitory dissipates during rest periods (after extinction)

- but each time a little bit remains permanent

- process repeats: extinction occurring every day, but each day a little bit more inhibitory is permanent

- after 8,9,10 days of extinction trials, all inhibitory is permanent and there is NO SPONTANEOUS RECOVERY

Contiguity

closeness in time between presenting CS and US

Optimal time interval

best time between presenting CS and US to get strongest CR

Stronger CS creates stronger CR

louder bell = more salivation

Second order conditioning

- Using an established CS CR relationships (can opener, food)

- pair CS with a new CS (cabinet door + can opener)

- take out the US (don't need it since animal already salivates)

- now the new CS (cabinet door) can make the cat salivate just like the original CS (can opener)

- US acts as a reinforcer to remind the cat of the original relationship

- original CS (can opener) now acts like the US, aka becomes a secondary reinforcer

Sensory pre-conditioning

- reversal of order of steps

- first, new CS is paired with old CS (no US) (tone + bell)

- then we establish original CS to US (reinforcement given) (bell = food)

- now with new CS, dog salivates (tone)

Generalization

similar stimuli create similar responses

Discrimination

- different stimuli create different responses

- less similar stimuli, less similar response

- can train the dog to only respond to high pitch tone if you only reinforce that high pitch and don't reinforce a low pitch

Preparatory CS response

- rabbit hears tone CS and receives shock US

- heart rate increases UR

- now because CS could be dangerous...

- tone CS tells body to slow down heart rate as a PREPARATORY RESPONSE for the incoming US

Theories on what gets learned during classical conditioning

- Pavlov: CS to CR is a conditioned reflex coming from the organism

- Modern view: CS provides important info about the US, there is an association between them (not a reflex)

Backward conditioning

- US before CS

- doesn't work - no association can be made

Operant conditioning - Thorndike

- under the subjects' control!

- cats in a puzzle box - must hit lever to be released

- learning is incremental, trial and error

Law of Effect

- response is strengthened when followed by reinforcement (satisfying state of affairs)

- response is weakened when followed by punishment (annoying state of affairs)

Reinforcement (operant)

- depends on (is contingent on) the response of the organism, in this case pushing a lever

- the reinforcement is getting out of the box

- anything that increases rate of responding

Behavior (operant)

- behavior of pushing lever is being learned

Mechanism (operant)

Law of Effect: consequences of cat's response

Delay (operant)

similar to contiguity - delaying reinforcement weakens response

Operant vs classical: reinforcement

O: depends on response of animal

C: US comes regardless of response

Operant vs classical: behavior

O: emitted and voluntary

C: elicited and involuntary

Operant vs classical: Mechanism

O: Law of Effect

C: contiguity

How are both classical and operant forms of conditioning?

- changes in the experiment affect the response frequency, whether that response is voluntary or not

- both depend on contiguity and contingency

Parallels to classical conditioning

- CR (salivation) = operant response (pressing of bar)

- US (food) = reinforcement (food or any other good thing)

- CS (tone) = discriminative stimulus (light)

Only change is order:

- classical: 1. stimulus CS 2. reinforcement US 3. response CR

- operant: 1. stimulus (light) 2. response (bar pressing) 3. reinforcement (treat)

Conditioned secondary reinforcer

- a stimulus paired with a reinforcer has the same effect as a reinforcer

- stimulus becomes a reinforcer through classical conditioning

- ex. once a bell is connected with food, it can be used like a US

Positive reinforcement

- increasing response by giving something desirable to subject

- ex. lollipop to a child for good behavior

Negative reinforcement

- increasing response by taking something bad away from subject

- ex. if rat presses lever, shocking stops

Positive punishment

- decreasing response by adding something negative to subject

- ex. when rat presses bar, gets shocked

Negative punishment

- decreasing response by taking something good away from subject

- ex. taking lollipop away from child if misbehaving

Operant conditioning example: rat pressing bar

- a rat presses a bar and when the light is on, received reinforcement

- when light is off, does not receive reinforcement

- operant response = pressing the bar

- positive reinforcement = giving food to rat after pressing bar - food does not appear unless pressing of bar occurs

Discriminative stimulus

- a signal that tells an individual what to do in a situation

- ex. light being on tells the rat to press the bar. Light = discriminative stimulus

- does NOT cause the response, only signals when response will be reinforced

Partial reinforcement effect

- reinforcing subject only sometimes, as opposed to continuously (every trial)

- extinction takes longer to occur

- stronger learning takes place

Schedules of reinforcement: interval

- reinforce a response after a period of time

Fixed interval

when rat presses bar, every 30 seconds rat is reinforced.

looks like a scallop design on graph because rat is waiting about 30 seconds to press the bar

Variable interval

- time is averaged. When rat presses bar, receives reinforcement every 30 seconds on average

- this makes it unpredictable, creating a straight slope on graph - rat is pressing the bar constantly bc it isn't sure when reinforcement will come

Schedules of reinforcement: ratio

- reinforcement after some number of responses

Fixed ratio

- ratio is the same - every 10th bar press receives reinforcement

- post reinforcement pause on graph - rat presses 10 times, takes a break to eat its food, and continues

Variable ratio

- ratio is averaged

- about every 10th bar press, receive reinforcement

- unpredictable

- straight slope on graph - rat presses constantly

Shaping - operant conditioning

- getting the subject to do one specific behavior by shaping its responses

- ex. if cat has to press a lever, reinforce if it turns towards lever, steps towards lever, etc. until it presses the lever

Chaining - operant conditioning

- getting subject to do a sequence of responses

- can be backwards or forwards (starting at response 10 or response 1)

- ex. training a dog to do an obstacle course

Contingency - classical conditioning

- likelihood of US depends on CS's presence or absence

- ex. the probability of getting shocked US depends on if tone CS is playing or not

Robert Rescorla experiment

- contingency matters more than contiguity

- 3 groups of rats

- when tone is on, all groups are shocked about 40% of the time period

- when tone is off: group 1 gets shocked 40% of time. group 2: 20% of time, and group 3: 10% of time

- fear responses to the tone: group 1: no fear conditioning = no fear of the tone. Doesn't matter if tone is playing or not, they will get shocked equally regardless. Group 2: considerable fear response. Group 3: associates the tone with significantly more shocks, and therefore is more fearful of the tone - their conditioned fear response is strongest out of all groups

Belongingness - classical conditioning

- a CS and a US could belong together - they work better together

Equipotentiality - classical conditioning

- all associations are arbitrary - putting any CS with any US

- the opposite of belongingness

Garcia and Koelling light/tone + shock experiment

- 4 groups of rats, 2 different CS and 2 different US

- Group 1: light/tone CS with shock US- DID avoid water with light/tone

- Group 2: light/tone CS with illness US - did not avoid water with light/tone

- Group 3: saccharin taste CS with shock US - did not avoid water with saccharin taste

- Group 4: saccharin taste CS with illness US - DID avoid water with saccharin taste

- what we learn: different CS and US's work better together (light/tone + shock and saccharin taste + illness)

Garcia Effect - Taste Aversion

- organisms learn to avoid food/drink after it was associated with feeling sick as a mechanism for survival

- contradicts classical conditioning:

- associations between CS and US happen in just ONE trial

- extinction is less likely to occur

- CS and US don't need to be presented within seconds - can be hours or even days before US

Garcia Effect - Rats

- make associations between taste and illness

- if presented with blue water with no sour taste or clear water with sour taste...

- rats avoid the CLEAR water with sour taste

- probably due to the fact that rats eat a variety of things and have to learn quickly which ones cause illness

Garcia Effect - quail

- make associations between color and illness

- if presented with blue water with no sour taste or clear water with sour taste...

- quail avoided BLUE water with NO sour taste

- probably due to hunting tactics when perched high up - have to discriminate between visual stimuli

Encoding

process of transforming what we perceive, feel, or think into an enduring memory

Storing

process of maintaining information in memory over time

Retrieving

process of bringing to mind information that has been previously encoded

Stage theory: long term mem

- duration = longer than one minute

- permanent

- infinite storage capacity

Stage theory: short term mem

- duration = seconds to minutes

- storage = 7 +/- 2 items "chunks"

- not permanent

Childhood amnesia

- can't form memories before the age of 2, therefore we don't remember them

- due to:

- lacking a fully developed hippocampus

- lacking fully developed language

- lacking remembering strategies

Flow of information in memory

- receive info / a stimulus

- goes into short term memory

- IF you rehearse this info...

- Goes into long term memory

Two types of rehearsal

- Maintenance: hold info in STM

- Elaborative: move info into LTM by thinking about it, questioning, etc.

Serial position effect

- participants told to listen to 20 words at a time and recall them in any order

- what we found: the position of the words in that order matters a lot

Primacy effect

- early part of the list is recalled better than the middle

- these words are recalled from LTM

- to reduce primacy, present the words faster to take away the chance to move words into LTM

Recency effect

- last part of list is recalled better than middle

- recalled from the STM

- to reduce recency, have a delay or activity in between 20th word and recall (STM will forget words)

Psychological code: short term memory

- phonological - based on sounds

- during recall, might mistake "boat" for "coat"

Psychological code: long term memory

- semantic - based on meaning

- during recall, might mistake "boat" for "ship"