Associative changes in human learning when cues with different learning histories are trained in compound.

The present experiments investigated associative changes during compound training involving cues with different learning histories. Across three human predictive learning experiments using the compound test procedure (Rescorla, 2000), participants learned about the effects of foods (cues) on inflammation, outcome ranging from -10 (or 0) to +10, in a hypothetical patient. Cues A and C were trained as excitatory (AW+10, CZ+10), whereas cues B and D as inhibitory (X+10 XB0 XD0 in Experiments 1 and 3; X+10 XB-10 XD-10 in Experiment 2). Subsequently, participants received compound training with AB+10, followed by a final test in which outcome expectations were assessed for the test compounds AD and BC. Moreover, Experiments 4a and 4b, using a forced-choice confidence test, demonstrated that participants were less certain about A after AW+10 training than about B after X+10 XB0 or X+10 XB-10 training. If cues that generate greater individual prediction error during the compound training undergo larger associative change, BC should receive higher ratings than AD. Alternatively, if participants preferentially attribute the compound outcome to the less certain cue, AD should receive higher ratings than BC. In Experiments 1 and 3, BC received higher ratings than AD, suggesting that the cue with greater individual prediction error, and higher certainty, underwent greater associative change. However, in Experiment 2, AD received higher ratings than BC, indicating greater learning about the cue with lower certainty, and lower individual prediction error. We discuss theoretical implications of our findings for the roles of prediction error and certainty in associative learning. (PsycInfo Database Record (c) 2026 APA, all rights reserved).