[Are there differences in processing times of variously complex rules in differential eyelid conditioning?]

Two logical relations, conjunction (AND) and exclusive disjunction (XOR) differ in formal complexity as well as in observable difficulties. AND results in less errors, fewer trials to criterion, and shorter processing time per trial than XOR. Two paradigms of differential classical conditioning are based on these rules. Negative patterning (A+, B+, AB-) equals XOR, and positive patterning (A-, B-, AB+) equals AND. We studied experimentally whether or not differences in processing time per trial are reflected in different optimal interstimulus intervals in human eyelid conditioning. Results of four groups (AND/XOR x 400/1200 ms; each group n = 10) suggest that differential conditioning could be observed in positive patterning (800-1000 ms) earlier than in negative patterning (1000-1200 ms).