Mazur Chapter 9: Stimulus Control & Concept Learning

Question 1

Probe Trials

Answer 1

Stimuli are presented to measure the responding but no reinforcer is given

Method of measuring generalization gradients

Question 2

What causes generalization gradients?

Pavlov

Answer 2

Innate

Generalization is an automatic byproduct of the conditioning process

Conditioning somehow spreads across to nearby neurons in the cerebral cortex

Question 3

What causes generalization gradients?

Lashely and Wade

Answer 3

Learned through experience

Explicit discrimination training along the dimension in question is necessary before the typical peaked generalization gradient is obtained

e.g. person needs to be reinforced when a certain color is delivered but not when it is absent

Without discrimination the individual would respond just as strongly to all colors

Question 4

nondifferential training

Answer 4

Every trial is the same

Produces a flat generalization gradient

e.g. same response rate for all frequencies

Question 5

presence-absence training

Answer 5

Produces typical generalization gradients

Question 6

Intradimensional training

Answer 6

same stimulus (e.g. tone) just different dimension ( e.g. tone frequency)

Produces narrower generalization gradients
e.g.frequency is only reliable cue.

Question 7

Sensory deprivation and generalization

Answer 7

Sensory deprivation can sometimes produce peaked generalization gradients even when animals have no
prior experience with a particular stimulus dimension

In other words, experience may not always be necessary to obtain

Question 8

Simultaneous discrimination procedure

Answer 8

Present two stimuli together (a dark gray card & a medium gray card) and the animal/human must choose between them

Differences in opinion if learning is absolute or relational [refer to other flashcards]

Question 9

absolute theory of stimulus control

Answer 9

animal has learned about the 2 stimuli separately

e.g. the medium gray gives me food, but the dark gray does not

Question 10

Relational theory of stimulus control

Answer 10

animal learned about the relationship b/w the 2 stimuli

it knows that the lighter gray card is associated with food

Question 11

Transposition

Answer 11

transfer of the relational rule

e.g. if medium gray (which before predicted reinforcer) and lighter gray are presented→ they chose the lighter gray

they realized that the lighter gray always gets the food

Question 12

Peak Shift

Answer 12

Shift in the generalization gradient in a direction away from the S-

Question 13

Spence’s Theory of Excitatory & Inhibitory Gradients

Answer 13

Accounts for both transposition & peak shift

In intradimensional training
excitatory generalization gradient develops around the S+ inhibitory generalization gradient develops around the S-

Spence’s theory does not do a good job predicting the results on a test called intermediate size problem

Some situations respond to the absolute properties of stimuli, however, considerable evidence points to and favors the relational approach to stimulus control

Question 14

Spence: associative strength

Answer 14

The ability of each stimulus to elicit a response

Question 15

Spence: net associative strength

Answer 15

Determined by subtracting a stimulus’ inhibitory strength from its excitatory strength

Question 16

Behavioral Contrast

Answer 16

Phenomenon in which responding to one stimulus changes as a result of a change in reinforcement conditions for another stimulus

Question 17

Gutman and Behavioral Contrast

Answer 17

Gutman’s study used a type of successive discrimination procedure known as multiple schedule: 2 or more reinforcement schedules that are presented at one time, in an alternating pattern, and each schedule is associated with a different discrimination stimulus (light & noise)

1st trial- light & noise were presented alternating on the same VI schedule, and eventually response rates were the same

2nd trial-extinction trial for the noise and eventually response rates reduced for the noise stimulus

surprisingly although the reinforcement schedule did not change for the light, the response rates increased

This is called behavioral contrast

Gutman found a Positive contrast- b/c it involved an increase in responding during the unchanged light component

If the light stimulus had decreased in responding during the unchanged light component it would be called-negative contrast.

Question 18

Behavioral reallocation hypothesis

Answer 18

Rapid responding in the unchanged component is possible because of the slower responding that occurs in the component that is changed to extinction

This gives the subject time to recover from fatigue, and they can respond faster to the unchanged component

Question 19

reinforcer habituation/satiation hypothesis

Answer 19

The more frequently a reinforcer is presented over a short priod of time, the less effective it becomes, because of habituation, satiation, or both

Question 20

Errorless Discrimination Learning

Answer 20

The learner typically makes few or no responses to the S-

Rather than waiting for steady responding to the S+, the experimenter introduces the S- in early in the training

Fading: An effective way to decrease the number of responses to the S – and improving the learners long-term discrimination performance

Question 21

Terrace example of Fading

Answer 21

Terrace knew that pigeons do not usually pack at a dark key, so at first, the S- was not illuminated green key but a dark key

Using a feeding procedure, he gradually progress from a dark to a dimly lit green key, and over trials intensive the green light was increased

In other words, the S- was introduced early in training, presented very briefly at first, and it was initially a stimulus that was unlikely to elicit responding

Question 22

Errorless Learning: education application

Answer 22

Pavlov explains that if we do not want our children to avoid school, then we need to make sure that they do not make incorrect responses b/c it could be aversive

Used fading to teach children with down syndrome shapes

First the cards only had a correct shape and two blank spaces

then very small incorrect shapes were added and over trials the sizes were increased.

Question 23

Drawbacks of errorless learning

Answer 23

children may have difficulty learning discrimination reversal in which the S+ and S- are reversed.

may also have trouble generalizing

Question 24

Learning Set

Answer 24

If an animals is given many discrimination tasks, one after another, each of which have a different pair of stimuli as the S+ and S-, they get faster and faster at solving the problem

Different species vary on their ability to develop new learning sets

Animals higher on the phylogenetic scales develop stronger learning sets.

Higher species have the ability to acquire more abstract info and can recognize similarities btw problems at developing a behavior strategy that improves performance on subsequent problems.

A learning set can also develop in discrimination reversal procedures- subject first acquires one discrimination and then the S+ and S- are switched. they learn quickly to switch to other stimulus

difficulty doing this may be indicator of brain damage (schizophrenics have trouble).

Question 25

Exemplar Theory of Concept Learning

Answer 25

Category such as bird consists of the memory of many individual examples of birds the person has seen

If a novel instance occurs that is similar to the examples it will be judged to be a member

Question 26

Prototype Theory of Concept Learning

Answer 26

A person develops a prototype–an idea of what an ideal or typical bird is like

If a new instance is similar to the prototype it becomes a central instance

If it is only moderately similar to the prototype then it becomes a peripheral instance

If it is not it will not be considered a member

Question 27

Feature Theory of Concept Learning

Answer 27

Person judges whether a given instance is a member of the category by checking for specific features

e.g. wings, feathers, beak, 2 legs, it sings, flies…etc

Question 28

The Structure of natural categories

Answer 28

People tend to judge category members as either typical (central instances) or atypical (peripheral instances)

Question 29

Animal Studies on Natural Concept Learning

Answer 29

Hernstein (1979) conducted a study using pigeons and their ability to discrminate between trees and nontrees

Pigeons are able to also do concept formation with: people, water, fish, artificial objects., and even ABC letters

Other animals such as monkeys, dog are also able to do this

Pigeons can also recognize that the view they are seeing (2 dimensional) is a 3 dimensional object

Able to categorize Monet’s paintings which depicted 3D objects

Question 30

Some similarities between animal & human concept learning

Answer 30

Animals differentiate b/w central & peripheral instances of a category ( they respond slower for an item that contains less positive features to the category)

Animals do not categorize complex stimuli simply on the basis of which individual features are present, but on how features are arranged into a whole

Concept learning is flexible→ animals can classify stimuli according to a variety of different criteria depending on the what the task demands

There is still speculation on whether animals are able to learn concepts that involved abstract relationships

Question 31

Developing stimulus Equivalence

Answer 31

situation in which subjects learn to respond to all stimuli in a category as if they are interchangeable even though they have been taught only a few relations between stimuli, not all possible relations

Researchers believe that Development equivalence sets is closely related to the ability to learn language

This would also mean that animals should not be able to learn equivalence sets b/c they do not hold language

Vaughhan (1988) demonstrated that pigeons do have an ability to learn equivalence sets

Question 32

Stimulus Control in Behavior Modification

Answer 32

Stimulus equivalence training

e.g. teaching children how to read
telling them to write a word down, and matching it to a spoken word

learning equivalences between ⇒ hearing a spoken word, seeing the written word, and reading the word out loud

Can also be used to teach college students a difficult topic

Question 33

Stimulus Control and Study Habitss

Answer 33

Fox (1962) explained that poor studying is due to ineffective stimulus control

The procedure involved the students establishing a particular time, place as a strong stimulus for studying a particular subject by repeatedly pairing this time/place with nothing but study behavior.

if they were getting distracted they were asked to read one more page and go home

the students grades eventually approved, however it is unknown if the improvement is due to specifically to this type of procedure as they also received training in other areas ( recite, review.. etc)

Question 34

Stimulus Control And Health Habits

Answer 34

Stimulus control techniques has also been done to improve eating habits/fighting obesity

Also is helpful in increasing physical activity
e.g. limiting the amount of hours of tv one watches → method called narrowing

Question 35

Stimulus Control and Insomnia

Answer 35

Although some cases may be due to medical concerns, some are due to inappropriate stimulus control

Individuals would be instructed to :

get out of bed if you are not falling asleep within a few minutes

do not do anything other than sleep in your bed ( no reading, TV)

These instructions are used to make the proper associations so that you may fall asleep in your bed.

These procedures for training stimulus control may hinge on the reduction of incompatible behaviors to eliminate an undesirable behavior

Question 36

Summary

Answer 36

Pavlov proposed generalization is an automatic by product of the conditioning process

Lashley & Wade said that experience is necessary for typical gradients to occur

stimulus control : absolute or relational?

spence’s theory accounts for peak shifts in generalization gradients (excitatory gradients around S+, inhibitory gradients around S-)

but does not explain intermediate size problem

Terrace developed an errorless discrimination training procedure which has been used in behavior modification programs with children

Concept formation-occurs when we treat one class of stimuli as either positive or negative

Pigeons can learn categories

Humans can learn equivalence sets, but some psychologists have found that some animals can too

Stimulus control techniques are used in behavior modification when a desired response seldom occurs in the presence of the appropriate stimulus
e.g. insomnia, studying