WEEK 8 LECTURE: STIMULUS DISCRIMINATION AND GENERALISATION

Vocabulary flashcards covering key concepts from the Week 8 notes on stimulus discrimination and generalisation.

Stimulus control

The process by which a particular stimulus (or context) comes to regulate whether a conditioned or instrumental response occurs.

Generalisation

Responding to stimuli that are similar to the training stimulus.

Discrimination

Responding differently to two or more stimuli.

Stimulus generalisation gradient

The pattern of responding as a function of how similar a test stimulus is to the training stimulus; the steeper the gradient, the stronger the stimulus control.

Peak-shift effect

A shift in peak response away from the trained stimulus (S+) due to overlap of excitatory and inhibitory generalisation gradients when S− is nearby.

Spence’s theory of discrimination learning

Excitatory generalisation to S+ and inhibitory generalisation to S−; differential responding reflects excitation to S+ and inhibition to S−.

Intrademensional discrimination

Discrimination where S+ and S− differ on a single stimulus feature (e.g., wavelength or pitch).

Elemental processing

Treating stimulus components as separate elements; elements can compete for control of the response.

Configural processing

Representing a stimulus as a configuration of multiple elements; the whole configuration determines the response.

Pearce’s configural processing model

A single configured representation (CS plus context) determines responding by similarity to the training configuration.

External inhibition

Reduced conditioned responding when the training CS is enlarged by adding an extra element.

Generalisation decrement

Reduced conditioned responding when a training CS is altered by removing an element.

Positive Patterning

A+/B+ (or C+/D+) with AB− (or CD−) where the compound predicts the outcome but the individual elements do not; cannot be solved by elemental processing and requires configural processing.

Relative stimulus validity

Discrimination like AB+ / BC− that requires separate representations for A, B, and C with appropriate excitatory or inhibitory associations.

Overshadowing

Competition among stimuli for learning; stronger salient stimuli can suppress learning about weaker ones.

Contextual cues

Environmental cues that gain stimulus control and modulate responses, even without direct reinforcement correlations.

Occasion setting (modulator)

A third cue that modulates the validity of a CS–US association (positive OS or negative OS).

CS+ (excitatory) vs CS− (inhibitory) in conditioning

In classical/instrumental conditioning, CS+ signals reinforcement (excitatory), while CS− signals nonreinforcement (inhibitory).

Acquired equivalence

Training different stimuli to produce the same outcome makes them functionally equivalent and promotes generalisation between them.

Acquired distinctiveness

Training AB− / AC− increases the distinctness between B and C, reducing confusion between similar stimuli.

Contextual cue control in discrimination

Contexts can control discrimination performance and generalisation even when not directly tied to reinforcement.

Discrimination training: simultaneous vs sequential

Discrimination is easier when stimuli are presented simultaneously (especially visually) than when they are presented sequentially.

Masking in discrimination training

Introducing a mask between stimulus presentations makes discrimination more difficult.

Similarity effects in learning

Greater similarity between S+ and S− can influence the rate and gradient of discrimination learning.

Garcia effect (bright and noisy water)

Evolutionarily predisposed associations where certain stimulus–US pairings (e.g., visual vs auditory) are learned more readily.

Acquired Equivalence vs Acquired Distinctiveness (summary)

Equivalence: different cues become functionally interchangeable; Distinctiveness: learning makes cues more distinct from one another.

Patterning discrimination (positive/negative)

Discriminations like AB+ / A− / B− or C+ / D+ / CD− that cannot be solved by analyzing elements alone and require configural representations.

Patterning training impact on processing

Training can push learners toward elemental processing (for some patterns) or configural processing (for others) depending on structure.