Abstract
Purpose. Priming has been shown to produce facilitation and inhibition in at least two frames of reference (e.g. Tipper & Weaver, 1998). Location-based priming is associated with the location to which attention is oriented while object-based attention is associated with moving objects independently of the location they were primed. Usually these separate effects are attributed to differences in the underlying representations activated by visual attention. Alternatively, object-based priming may reflect a spatial process that dynamically updates the successive locations occupied by the activated object. We investigate this distinction by measuring object-based priming for objects moving at different velocities. Method. Participants (N=8) responded to a pair of moving targets that were validly or invalidly primed by their features (colour and shape). Four object velocities were used and location and object-based effects were disambiguated using four prime conditions: (i) features valid, location valid, (ii) features valid, location invalid, (iii) features invalid, location valid and (iv), features invalid, location invalid. Results. The results demonstrate a distinction between priming associated with the cued location and that associated with the moving object. Location-based priming persists despite changes in target velocity while object-based priming declines linearly as the target's velocity increases. Conclusion. The data support a process that dynamically updates the successive locations of a moving object that has been primed by non-spatial features. Priming associated with slow moving objects is equivalent to that associated with the location at which the object was primed. As velocity increases and the spatio-temporal coherence of the selected object is disrupted, priming reduces as the allocation of attention to successive locations becomes more difficult.