Negative priming for target selection with saccadic eye movements.

We conducted a series of experiments to determine whether negative priming is used in the process of target selection for a saccadic eye movement. The key questions addressed the circumstances in which the negative priming of an object takes place, and the distinction between spatial and object-based effects. Experiment 1 revealed that after fixating a target (cricket ball) amongst an array of semantically related distracters, saccadic eye movements in a subsequent display were faster to the target than to the distracters or new objects, irrespective of location. The main finding was that of the facilitation of a recent target, not the inhibition of a recent distracter or location. Experiment 2 replicated this finding by using silhouettes of objects for selection that is based on feature shape. Error rates were associated with distracters with high target-shape similarity; therefore, Experiment 3 presented silhouettes of animals using distracters with low target-shape similarity. The pattern of results was similar to that of Experiment 2, with clear evidence of target facilitation rather than the inhibition of distracters. Experiment 4 and 5 introduced a distracter together with the target into the probe display, to generate a level of competitive selection in the probe condition. In these circumstances, clear evidence of spatial inhibition at the location of the previous distracters emerged. We discuss the implications for our understanding of selective attention and consider why it is essential to supplement response time data with the analysis of eye movement behaviour in spatial negative priming paradigms.