Sources of Stimulus Control in Tests for Emergent Stimulus Relations

The team taught two kinds of equivalence classes. One group learned tact first, then intraverbal. The other group got the reverse order.

After training, the researchers added "disruptors." They blocked verbal mediation for some tests and blocked visual imagery for others. They wanted to see which training path leaned on which hidden skill.

Blocking talking to yourself hurt both groups the same. Blocking pictures in your head only slowed the kids who got intraverbal-first training.

That means the training order decides what private tool you later need. Tact-first students stored the links in a way that did not need mental pictures.

Allen et al. (2001) showed that naming the items does not shield equivalence from later conflict. McGee et al. now add that naming is not the only weak spot—visual imagery can be shaken too.

Layton et al. (2022) used extra reinforcement as a disruptor and found context matters for DRA persistence. The same logic applies here: add the right disruptor and you see which cues the learner was really using.

BOWER et al. (1963) proved that blocking silent counting wrecks fixed-interval timing. Sixty years later, McGee shows the same trick works to expose the hidden props behind emergent relations.

If you run equivalence-based instruction, start with tacts. That small switch builds classes that survive when a learner's mental pictures fade. You get tougher, maintenance-ready emergent relations without extra teaching time.