Journal of Vision - Attentional pursuit is faster than attentional saccade, by Horowitz, Holcombe, Wolfe, Arsenio, & DiMase

Todd S. Horowitz	Visual Attention Laboratory, Brigham & Women’s Hospital, and Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
Alex O. Holcombe	School of Psychology, Cardiff University, Cardiff, Wales, United Kingdom
Jeremy M. Wolfe	Visual Attention Laboratory, Brigham & Women’s Hospital, and Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
Helga C. Arsenio	Center for Women’s Mental Health, Massachusetts General Hospital, Boston, MA, USA
Jennifer S. DiMase	Department of Psychology, Yale University, New Haven, CT, USA

How quickly can we shift the focus of visual attention? We compared the rates of two types of attentional shifts: attentional saccades (shifts between objects) and attentional pursuit (shifts along with a moving object). Instead of measuring the time required for a single shift, which confounds shift time with cue interpretation time, we measured the pace at which observers could make multiple successive shifts in a predictable order. We find that successive attentional saccades between objects are quite slow (300-500 ms). The object-based theory of attention predicts that attention should shift between locations more quickly when in pursuit of a moving object. Our results support this theory. Attentional pursuit is substantially faster - taking only 200-250 ms to cover the same distance. “Indexing” a moving object (keeping track of one object) can be done at even faster rates, supporting a distinction between attending to and indexing objects.