Selective effects of division of attention on discrimination conditioning

The contribution of attention to learning was examined in delay, trace, discrimination, and discrimination reversal eyeblink conditioning in young healthy adults. Participants performed either single- or two-cued conditioning paradigms with three levels of distraction: no distraction (full attention), concurrently watching a silent movie, or concurrent verbal shadowing. Conditioning for single-cue delay and trace conditioning paradigms was unaffected by the level of distraction. Conditioning for the two-cue paradigms of discrimination and discrimination reversal was reduced greatly when attention was divided. Silent movie watching allowed for some acquisition (CRs to the CS+) but no discrimination (differential responses to CS+ vs. CS-). Verbal shadowing eliminated both acquisition and discrimination. These results indicate that, in the human, attention makes a critical contribution to the successful acquisition of two-cue eyeblink conditioning tasks that require discrimination and discrimination reversal.