Object-based eye movements: the eyes prefer to stay within the same object.

The present study addressed the question of whether we prefer to make eye movements within or between objects. More specifically, when fixating one end of an object, are we more likely to make the next saccade within that same object or to another object? Observers had to discriminate small letters placed on rectangles similar to those used by Egly, Driver, and Rafal (1994). Following an exogenous cue, observers made a saccade to one end of one of the rectangles. The small target letter, which could be discriminated only after it had been fixated, could appear either within the same or at a different object. Consistent with object-based attention, we show that observers prefer to make an eye movement to the other end of the fixated same object, rather than to the equidistant end of a different object. It is concluded that there is a preference to make eye shifts within the same object, rather than between objects.