Temporal coding in Pavlovian conditioning: Hall-Pearce negative transfer.

The Hall-Pearce (1979) negative transfer effect in rats was used to examine whether temporal relationships are coded as part of the informational content of associations that results from CS-US pairings. The transfer effect consists of a deficit in conditioned responding following CS-USstrong pairings in Phase 2 that results from prior CS-USweak pairings in Phase 1. Using conditioned bar-press suppression, we found that gaps of different duration between CS termination and US onset in the two training phases resulted in less of a Hall-Pearce negative transfer effect than did an equivalent gap in the two training phases. The results are discussed with respect to the temporal coding hypothesis (Matzel, Held, & Miller, 1988), the Pearce and Hall (1980) model, and Bouton's (1993) interference model.