Stimulus Equivalence Overview

Stimulus Equivalence

• Stimulus equivalence involves accurate responses to untrained stimuli, allowing individuals to treat different stimuli as interchangeable based on limited training.
• Reflexivity, symmetry, and transitivity are core components defining stimulus equivalence classes, all representing emergent behaviors.

Types of Stimulus Equivalence

• Key types include:
  • Reflexivity
  • Symmetry
  • Transitivity

Reflexivity

• Reflexivity is when an individual matches a stimulus to itself (A=A) without prior training, e.g., matching two pictures of an apple.

Symmetry

• Symmetry allows for bidirectional matching (A=B, B=A) without training, such as matching an object to a previously seen picture after training with the picture.

Transitivity

• Transitivity refers to the ability to match untrained examples based on prior learning: if A=B and B=C, then A=C.

Murray Sidman

• Sidman noted the significance of equivalence relations in language and social interactions, observing that individuals often react to symbols as if they were the actual objects or events.

Higher Order Classes of Behavior

• Higher-order classes encompass multiple operant classes that can influence behavior.
• These classes allow for novel behaviors and may interact differently with contingencies arranged for them than their component classes, resulting in behaviors that persist even without reinforcement.

Generalised Operants

• Generalised operants apply contingencies to entire behavior classes rather than specific instances, reinforcing the overall behavior of imitating instead of individual acts.

Types of Concepts

• Two main categories of concepts exist:
  • Perceptual
  • Associative

Perceptual Concepts

• Perceptual concepts are divided into:
  • Dimensional categories (e.g., color, size)
  • Natural categories that encompass groups sharing certain abstract properties, such as "birds."

Associative Concepts

• Associative concepts are relational and lead to functional equivalence classes, which align with stimulus equivalence classes.

Functional Equivalence Classes

• Functional equivalence classes consist of arbitrary stimuli that elicit the same response or function.

Herrstein's Experiment

• Herrstein's experiment demonstrated concept development by teaching pigeons to peck at trees, with trees designated as S+ (positive stimuli) and absence of trees as S- (negative stimuli).

Vaughan's Test

• Vaughan utilized a similar methodology as Herrstein using arbitrary stimuli without shared features, successfully teaching pigeons to learn the trained sets and demonstrating that the stimuli's functions could shift after just one trial.