EYE-MOVEMENTS DURING PARALLEL-SERIAL VISUAL-SEARCH

Two experiments (one using O and Q-like stimuli and the other using co lored-oriented bars) investigated the oculomotor behavior accompanying parallel-serial visual search. Eye movements were recorded as partici pants searched for a target in 5- or 17-item displays. Results indicat ed the presence of parallel-serial search dichotomies and 2:1 ratios o f negative to positive slopes in the number of saccades initiated duri ng both search tasks. This saccade number measure also correlated high ly with search times, accounting for up to 67% of the reaction time (R T) variability. Weak correlations between fixation durations and RTs s uggest that this oculomotor measure may be related more to stimulus fa ctors than to search processes. A third experiment compared free-eve a nd fixed-eye searches and found a small RT advantage when eye movement s were presented. Together these findings suggest that parallel-serial search dichotomies are reflected in oculomotor behavior.