David and Goliath-size does matter: size modulates feature-response binding of irrelevant features.

Stimulus and response features are integrated together in episodic traces. A repetition of any of the features results in the retrieval of the entire episodic trace, including the response features. Such S-R bindings have been suggested to account for different priming effects like repetition priming, negative priming and so on. Previous studies on repetition priming have found priming effects to be size invariant. The present study examines whether the size invariance in previous priming studies was due to the absence of size-response binding. In two experiments, size was varied orthogonally to the response, either without varying any other stimulus features (Experiment 1) or while varying another stimulus feature (Experiment 2). A significant size-response binding effect was observed in Experiment 1 but not in Experiment 2. The results suggest that size is involved in feature-response binding and can retrieve the response upon repetition. However, this retrieval is extinguished if another stimulus feature is varied simultaneously. The results are discussed against the background of S-R binding as the mechanism underlying repetition priming.