Chapter 8: Stimulus Control Of Behavior

Stimulus Control of Behavior

Everyday behaviors are influenced by environmental stimuli. For instance, students maintain silence in libraries, individuals seek shelter from rain, and they wear sunglasses in sunny conditions. Instinctively, animals adapt their behavior to changes in their environment for survival.

Definition of Stimulus Control

An organism is under "stimulus control" when its actions are directed by a specific stimulus. Reynolds (1961) demonstrated this with pigeons that displayed differential responding to separate stimuli when only one was present, showcasing stimulus discrimination.

Stimulus Generalization

Stimulus generalization occurs when an organism responds similarly to multiple stimuli. Pavlov first discovered this phenomenon, noting that animals trained with a specific tone would also respond to similar tones, where closer frequencies to the conditioned stimulus (CS) evoked larger conditioned responses (CR).

Generalization Gradients

Generalization gradients, which measure sensitivity to stimulus changes, were studied by Guttman & Kalish (1956). The most potent stimulus controls behavior, leading to a steep gradient that signifies high stimulus control.

Overshadowing and Reinforcement

Pavlov's research indicated that when two stimuli are presented, the more salient one overshadows the lesser one. The control of behavior is also influenced by the type of reinforcement available, which varies in appetitive versus aversive contexts, as demonstrated by Foree and Lolordo (1973) with pigeons.

Instrumental Response Type

The type of response required from an organism can influence stimulus control. Research by Dobrzecka et al. (1966) showed that responses based on location were governed by spatial features, while quality-differentiated responses aligned more with the stimulating quality.

Discrimination Training

Discrimination training is crucial for establishing stimulus control over behavior. In experiments, rats and pigeons can learn to respond to specific stimuli while ignoring others, as shown in studies assessing blink conditioning in rats and lever pressing in pigeons.

Spence’s Theory of Discrimination Learning

Spence (1936) proposed that animals learn about both positive (S+) and negative (S-) stimuli through excitatory and inhibitory conditioning, resulting in generalization gradients that reflect their responses to stimuli based on their relative strength.

Contextual Control of Behavior

Behavior can also be contextually influenced, where contextual cues gain control without signaling reinforcement. Studies demonstrated that varying contexts could modulate stimulus relations, affecting behavior responses.

Conditional Relations in Conditioning

Conditional control requires establishing a modulator indicating when a CS predicts reinforcement. Modulators don't develop excitatory properties themselves but facilitate conditioned responses when paired with stimuli that lead to reinforcement.

Occasion Setting

Occasion setting indicates when reinforcement will occur, contrasting with conditioned inhibition, which signifies absence of reinforcement. This indicates that understanding probabilistic relationships and distinguishing between reinforcement contexts is essential in learning behavior control.