Stimulus Control of Operant Behavior Discrimination Generalization Generalization Gradients Peak Shift Concepts Overview of stimulus control of operant behavior

I. Operant Discrimination Known as the study of discrimination learning or stimulus control Discriminative stimulus - Signals that reinforcement will be forthcoming if the response occurs (S+ or S d ) Signals that reinforcement will not be available, even if the response occurs (S v )

Discrimination Animals learn to demonstrate differential patterns to responding to different stimulus conditions

Response Pattern Add info of your choice here Add text, graphic or photo at left S+ S- Resp/Min

II. Generalization Similar patterns of responding to similar stimulus conditions The opposing qualities of discrimination

III. Generalization Gradients CS+ Early in discrimination training

Generalization Gradients CS+ Later in discrimination training

Generalization Gradients CS+ Excitatory Pattern of Responding

Generalization Gradients CS- Inhibitory Pattern of Responding % CR

Generalization Gradients CS+ Excitatory of Responding % CR to tone 1 KHz

Generalization Gradients CS- Inhibitory Pattern of Responding % CR to tone 570 nm

Predictiveness and Redundancy Conditioning will occur to the stimulus which most predictive An especially salient CS may overshadow the other stimuli

Overshadowing Depends upon nature of the environment, the past history of the animal and similar issues Highly salient stimulus qualities often overshadow other stimuli Specific features of the stimulus may be attended to

Attention Training Relevance must be learned Behavior must be demonstrated Transfer of training studies –Paying attention is a separate part of the discrimination learning

Attention Training Dimensional shift learning paradigm –Intradimensional shift - Train to CS+ quality, shift to different type of same dimension (e.g. shift from red to blue for CS+) –Extradimensional shift - Train to CS+ quality, shift to different dimension (e.g. from color to shape for CS+)

Attention Training Extradimensional shift is more difficult

IV. Process of Generalization Extinction builds to CS+ and inhibition builds to CS- Early work of Spence 1936, 1937; and Hull 1943, 1952 According to Spence’s theory, excitation and inhibition add together in an algebraic fashion

Peak Shift Phenomenon CS+ CS- Response Strength

Peak Shift Phenomenon CS+ CS- Response Strength

V. Natural Concepts Concepts are related by unifying or common properties Abstract concepts –“Same” or “different” –Often not limited to specific concrete qualities

V. Natural Concepts Some processes –Matching to sample R Peck GR Reinforce

V. Natural Concepts Some processes –Oddity responding R Peck GR Reinforce

V. Natural Concepts Wittgenstein in 1953 It is not clear what specific features or qualities are being responded to What is a dog? What are the qualities of “dogginess?”

V. Natural Concepts Herrnstein work in the 1980s Demonstrated discrimination of natural objects by pigeons Sort stimuli by water, trees or a particular person Organisms as simple as pigeons can reliably demonstrate this discrimination

Learning Theory and Memory Are there behavioral ways to describe remembering and knowing? Some procedures include delayed matching to sample –Matching accuracy decreases as a function of time

Matching Accuracy Over Time Percentage Correct Seconds

Matching Accuracy Over Time and Sample Duration Percentage Correct Seconds sec sample 8 sec sample 4 sec sample

Working Memory Memory is an active process –Susceptible to interference Retroactive interference - interfering stimulus comes after the stimulus to be remembered Proactive interference - interfering stimulus comes before the stimulus to be remembered

Working Memory Symbolic matching works as effectively as direct stimulus matching –For example, red to vertical lines is remembered as well as red to red –Directed forgetting - stimulus learning is followed by a signal that the stimulus is to be remembered or not –It appears memory is an active process

Spatial Memory and Cognitive Maps Memory for places –Maze learning studies –Little indication of decay over time –Tends to be accounted for by a cognitive representation of space