From tusk till horn: Modulating feature boundaries in action control.

In the literature on action control, it is assumed that all stimulus features that occur in an action episode are integrated together with the response features into an event file. Any ensuing repetition of a feature stored in this event file leads to the retrieval of the entire event file, causing stimulus-response (S-R) binding effects because of the relation between repeated and changed features. However, the retrieval depends on the extent to which a particular feature is actually repeated and thus touches the question of what constitutes a feature. Since not only perceptual but also conceptual features are assumed to be bound, the boundaries between feature representations might not only be fluid but also modulable. In this study, we evaluated whether a direct manipulation of feature boundaries is possible. In three experiments (cumulative n = 217), by adding additional counting tasks to a distractor-response binding task, we either merged or separated feature categories, causing a significant difference in S-R binding effects-merged feature categories caused weaker S-R binding effects compared to separated feature categories. The results indicate that merged features were actively brought to be processed as more similar to each other. We interpret our data under the broader and old question of what a feature actually is and suggest that feature boundaries are task dependent. Human agents are highly flexible in controlling the internal representation of objects they interact with. (PsycInfo Database Record (c) 2025 APA, all rights reserved).