Effects of a dynamically changing response set overlap on n - 2 repetition costs.

N - 2 repetition costs are a marker for inhibition processes during task switching that are supposed to reduce interference from currently irrelevant information. The present study aimed at elucidating effects of response set overlap on n - 2 repetition costs while keeping stimulus set overlap constant. For this purpose, each task was associated with two different response sets. The relevant response set was visually cued in every trial. N - 2 repetition costs were present when the response set overlapped from trial n - 2 to trial n - 1. In contrast, they were abolished when the response set switched. This result is interpreted in terms of stronger interference for overlapping response sets that need to be inhibited to a high degree, resulting in large n - 2 repetition costs. Furthermore, the present results support the notion that two means for interference reduction, task inhibition and task shielding, are deployed in a flexible way depending on environmental demands.