Search Termination When the Target is Absent: The Prevalence of Coarse Processing and Its Intertrial Influence

The visual system can flexibly distribute attentional resources to search areas, with this reflected in the spatial scale of information processing. Visual processing can be either coarse at a global level, or fine at a local level. Previous studies showed the transition between these 2 modes, from coarse to fine, but it has been unclear when and how this occurs. The current study investigated how processing modes change depending on target presence and distractor heterogeneity. In our experiments, participants searched for a uniquely oriented target. Experiment 1 showed that toward search termination, targetabsent trials revealed larger saccadic amplitudes with shorter fixation durations, compared with targetpresent trials. This suggests that the coarse processing mode appears reflecting the tendency to reject multiple distractors at a broad spatial scale in target-absent trials, if all the items are deemed to-berejected. On the other hand, in target-present trials, the transition toward focal processing is provoked by a target. Moreover, Experiment 2 showed decreased search durations when preceded by a target-absent trial. This implies that processing modes can be transferred between trials and that maintaining the coarse mode from a previous target-absent trial can be advantageous for starting a new search trial.