Abstract
Instruction-based learning (IBL) is an essential human skill, enabling flexible and efficient application of novel rules. Previous studies focused on instructions specifying affirmative (or positive) stimulus-response (S-R) rules (i.e., if condition A, then execute action X). Despite their frequent occurrence in our daily lives, negative instructions (i.e., if condition B, then do not execute action X but execute alternative action Y or Z) remain underrepresented in IBL research. In the present study, we conducted three experiments in order to assess the basic behavioral characteristics of this particular instruction type. Experiment 1 revealed reduced implementation efficiency relative to positive instructions as indicated by persistently prolonged response times, suggesting a continued impact of the negated 'instruction-related' S-R (B-X) association. At the same time, a distinct affirmative 'implementation-related' S-R (B-Y or B-Z) association gained strength over the course of repeated rule implementation, as evidenced by a decreasing tendency to alternate between correct response options. This pattern was replicated in Experiment 3. Experiment 2 employed neutral S-R instructions for which type information (positive or negative) was available only during later implementation. The comparison between Experiments 1 and 2 revealed an implementation benefit of advance instruction type information for negative instructions. This suggests that the negation is proactively integrated into the task model for the benefit of upcoming implementation. Overall, our results highlight the unique properties of negative instructions in the context of IBL. In particular, the dual representational nature could enable disambiguation of functional states in rule transformation processes crucial to rapid, novel learning.