Feature type modulates priming in visual search

When target features are repeated across consecutive search trials, response times (RTs) are faster compared to trials in which target features change (eg Maljkovic and Nakayama, 1994 Memory & Cognition 22 657 ^ 672). To investigate how feature type and the roles that features play in target definition affect priming, we manipulated the roles of colour and orientation in defining the search target, while participants responded to the orientation of a `T' inside this target. In experiment 1, the target differed from distractors in orientation, while target colour was irrelevant to the search. Repeating irrelevant target colour produced significantly faster RTs, but repeating target-relevant orientation slowed RTs. In experiment 2, the roles of colour and orientation were reversed: the target now differed from distractors by its colour, while target orientation was irrelevant. Again, a significant RT advantage was found for repeating target colour, but not for repeating target orientation. Thus, it seems that repetition priming is at least partly dependent on feature type, rather than the role of feature type in target definition. Further- more, these data are not consistent with suggestions that an episodic representation of the target (Huang et al, 2004 Memory & Cognition 32 12 ^ 20) is stored across trials. [Supported by a BBSRC postgraduate studentship.]