The effect of retention interval on stimulus over-selectivity using a matching-to-sample paradigm.

Reed (2006) asked adults without disabilities to play a matching game. A sample picture popped on screen, then disappeared. After a wait of zero, four, or twelve seconds, two comparison pictures appeared. The adults had to pick the one that matched the sample.

The computer quietly counted which part of the sample—color, shape, or pattern—the adults used to make their choice.

When the wait was zero, adults looked at most parts of the sample before choosing.

When the wait grew to twelve seconds, they looked at only one part and ignored the rest. Longer gaps made their focus narrow, a pattern called overselectivity.

Parsons et al. (1981) saw the opposite trend in children. They taught kids to say the sample name aloud during the wait. Those kids stayed accurate even after long delays.

Reed (2006) shows adults without such coaching grow more overselective as delays lengthen. The two studies seem to clash, but the gap is in coaching. Kids who learn a mediating trick keep broad stimulus control; adults without the trick lose it.

Rojahn et al. (1987) used the same adult matching setup, but they swapped in new pictures and added mild penalties. Their work confirms the procedure is solid; Phil simply turned the lens from punishment effects to delay effects.

If you run matching tasks, memory games, or conditional-discrimination programs, shorten the delay or teach the learner to rehearse out loud. A four-second pause may look harmless, yet it can shrink stimulus control. Add prompts, songs, or labels during the wait to keep attention wide.