Consistent practice of a stimulus-response (S-R) mapping is assumed to establish corresponding S-R associations that facilitate processing when the mapping is retained and produce interference when the mapping is reversed. In addition, previous research using EEG recordings in a conflict task found alterations in brain activity associated with action monitoring and error adaptation following the reversal of S-R mappings.
To assess the costs of reversing S-R mappings in a conflict task independent of practice, we used a four-choice Stroop task in which the response assignment for two of the colors was reversed after the first half of the experiment. For the other two colors, however, the initial S-R mapping was retained. This partial reversal procedure allowed us to compare performance for reversed and retained stimuli in the second half of the experiment. We found persistent reversal costs throughout the experiment, which were specifically limited to trials in which the stimulus category was switched (i.e., from a retained stimulus to a reversed stimulus). Notably, Stroop interference and conflict adaptation, as indicated by the (confound-minimized) Congruency Sequence Effect (i.e., a reduction in the Stroop effect after incongruent compared to congruent predecessor trials), remained unaffected by the reversal.
Taken together, our results demonstrate substantial costs of partially reversing S-R mappings in a conflict task. These costs, however, were context-dependent (not present when the mapping was also reversed in the preceding trial) and did not affect conflict processing, underscoring the nuanced impact of established S-R associations on different aspects of cognitive processing.