Evidence of precurrent responses expanding equivalence classes in a delayed matching-to-sample task

Area of Science:

• Cognitive Psychology
• Behavioral Science
• Learning and Memory

Background:

• Delayed matching to sample (DMTS) is known to improve stimulus equivalence formation.
• Precurrent responses, often verbal, can mediate retention intervals and comparison selection in DMTS.
• These precurrents may link experimental stimuli to pre-existing meaningful concepts.

Purpose of the Study:

• To investigate if precurrent responses expand learned equivalence classes by acting as nodes between experimental and meaningful stimuli.
• To test the hypothesis that mathematical problem-solving during DMTS intervals can serve as a precurrent response that expands classes.

Main Methods:

• A delayed matching to sample (DMTS) procedure was employed with human undergraduates.
• Participants learned simple stimulus-response relations (A1B1, A2B2).
• During DMTS trials, participants solved mathematical problems (e.g., yielding 12 or 9) that were linked to specific stimuli (C1, C2).
• Response-as-node and parity tests were used to assess class expansion.

Main Results:

• Ten out of eleven participants demonstrated that their mathematical problem-solving responses expanded the equivalence classes.
• Participants successfully related stimuli B1/C1 to the number 12 and B2/C2 to the number 9.
• Parity tests using 'even' and 'odd' further supported the class expansion hypothesis.

Conclusions:

• Precurrent responses, specifically those involving mathematical problem-solving, can function as nodes that expand learned stimulus equivalence classes.
• This mechanism helps explain why DMTS procedures enhance performance in stimulus-equivalence studies.
• The findings have implications for designing effective stimulus-equivalence training paradigms.