Maintaining Visual Attention over Time: Effects of Object Continuity

Maintaining visual attention in dynamic environments is an important function of the visual system. The visual system appears to modulate attentional state to identify a target embedded in a rapid sequence of nontargets; typically, target identification gets better as the number of preceding items increases and is maintained at this increased level. We examined the temporal characteristics of the visual system that contribute to maintaining attentional state. Inserting one-second temporal gap in the sequence reset the elevated attentional state. However, the results also suggested that the attentional state was maintained as long as the sequence was interpreted as a single event (i.e., the object continuity was maintained). It has been proposed that ‘object files’ keep track of visual items and accumulate information as they move and change. It is also known that objects' features (shape and/or color) affect the distribution of attention within objects. In a separate set of experiments, we examined whether the change detection of feature-location binding in moving visual objects would affect the attentional distribution within objects by using a probe-detection paradigm. The results showed that the performance of irregularity detection did not influence the attentional distribution within objects. This finding implies that attentional distribution within objects occurs independent of object continuity.