3: The role of discriminative stimulus on behaviour

Question 1

Define extinction. It is observed in which types of conditioning?

Answer 1

The reinforcer (Rft) is removed, resulting in decrese/ceasing of the R

Question 2

What are discriminative stimuli? What type of conditioning does it operate with? Give an example

Answer 2

Discriminative stimuli are stimuli paired with a R so that Rft is only received when that pairing is present. This operates with operant/instrumental conditioning.

Eg a rat is only given Rft when it presses the lever when a light is on.

Question 3

What is the result of partial Rft (PRF) and continuous Rft (CRF) on extinction rate? This effect is known as:

Answer 3

CRF results in more rapid extinction. This effect is known as PREE (partial reinforcement extinction effect).

Question 4

What is the result of partial Rft (PRF) and continuous Rft (CRF) on extinction rate? This effect is known as:

Answer 4

CRF results in more rapid extinction. This effect is known as PREE (partial reinforcement extinction effect).

Question 5

Define SD (S+) and S-delta (S-)

Answer 5

SD= Discriminative stimulus (S+): This is the S that will lead to Rft of behaviour, it indicates what the Rft will be.

S-Delta (S-) is a stimulus that will not lead to Rft.

Question 6

‘Setting the occasion’ is otherwise known as

Answer 6

Discriminative stimuli (SD)

Question 7

what is a critique of SD theory

Answer 7

It may be too simplistic. Responding in the presence of SD is sensitive to the value of the Rft.

Question 8

Context (environmental cues), emotional/physialogical states and the passing of time could all act as….

Answer 8

S+ (SD) or S- (S delta) , indicating whether or not their actions will be reinforced.
S+–>R=Rft
S—>R=no Rft

Question 9

Define spontaneous recovery and name the 3xRs which demonstrate it

Answer 9

Original R due to association reemerges following extinction

• Reinstatement- When Rft returns the R is reinstated ?? /R reappears when US is reintroduced
• Rapid re-acquisition- It’s easier to retrain the R a 2nd time
• Renewal- the R may return in a different environment eg Rft and therefore tantrums have ceased (extinction) at home but in a new environment such as the supermarket the tantrums are renewed

Question 10

Extinction is a form of what kind of learning?

Answer 10

Discriminative learning: Extinction acts as an SD because the context teaches the animal to change their behaviour

Question 11

What is the ABC of instrumental learning? Otherwise known as Stimulus–>Response–>Reinforcer

Answer 11

Antecedence–>Behaviour–>Consequence

Question 12

How would an experimenter ascertain which features of a stimulus are salient?

Answer 12

By varying the features

Question 13

What does the steepness of a line on a generalisation graph display?

Answer 13

The subjects level of discrimination to the generalised stimuli

Question 14

Define stimulus control and give an example

Answer 14

The effect of SD to on behaviour (R): R is observably different in the presence of diff stimuli.

An example is environmentally controlled (env as SD) eg workmate is not anxious at work but is anxious at the pub. There are common stimuli (eg me) and contrasting S (work/pub)

Question 15

A lack of stimulus control would result in…whereas a biological sensory limitation would result in…

Answer 15

A lack of stimulus control would result in the organism failing to discriminate, whereas a biological sensory limitation would result in an inability to discriminate

Question 16

Define autoshaping (classical conditioning) and the difference compared to shaping.

Answer 16

Autoshaping is a R displayed by an animal when that R is not directly associated with Rft, only the S is associated w Rft. eg pigeon begins pecking at light when light signals food Rft. Previously food would appear without light, but the association is learnt. Shaping EDITTTTTT

Question 17

Define differential Rft, and what it facilitates acquiring

Answer 17

Rft is delivered only for the appropriate R. Extinction is applied for other Rs. This process facilitates discrimination.

Question 18

The rate at which a rat licks at the tube which has previously delivered water is thought to correlate with…

Answer 18

the rate at which the rat expects to receive water

Question 19

Define discrimination and generalisation: 2 sides of the same coin

Answer 19

Generalisation: learning generalises to similar S which created R, whereas discrimination refers to S which will cause different Rs

Question 20

What is the difference between sensory limitation and lack of stimulus control in generalisation?

Answer 20

Sensory limitation: organism is incapable of discriminating

Lack of stimulus control: Organism doesn’t discriminate

Question 21

Give an example of discrimination learning producing biases in generalisation to other stimuli

Answer 21

When a child tells a joke in different environments they receive different rewards or punishments. They therefore learn to discriminate the appropriateness of the context.

Question 22

Describe the effects of S+ and S- in peak shift on the generalisation gradient between the control group and discrimination group of pigeons tested between 2 similar shades of green

Answer 22

The control group were only given the S+shade of green and their R generalised around that shade of green.

The group who were given the S+ shade as well as the S- shade of green showed a bias FURTHER towards the S+ gradient direction, surpassing the exact shade of S+ and exaggerating it’s difference to the S- shade.

Question 23

Define peak shift in simple terms, using S+ (SD) and S- (S delta) to illustrate.

SD = Discriminative stimulus
S- = The stimulus which doesn't reinforce the behaviour

Answer 23

Peak shift is the generalisation shift AWAY from the S+ (SD) stimulus in the direction of the S- (S delta)

Question 24

What is a prototype in the context of categorisation?

Answer 24

eg pigeons can learn to discriminate between photos with and without trees. To do this takes them 1000s of trials, but eventually they have formed prototypes of the images w trees to compare against.

Question 25

What is the difference between shaping and autoshaping, and how does autoshaping challenge Skinner’s principle of Rft?

Answer 25

Shaping: Animal is rewarded incrementally for increasing approximations of desired R.

Autoshaping: Animal is rewarded regardless of R, eg. food is delivered to pigeon regardless of whether it pecks at the light or not, but the pigeon nonetheless begins the R of pecking the light.

This challenges Skinner’s theory that behaviour needs Rft to develop.