Recent theories of attention have emphasized the role of object-based
representations in visual selection. One defining property of any obje
ct is spatiotemporal continuity. The present experiments show that the
continuity property may underlie two seemingly unrelated perceptual p
henomena: attentional capture by abrupt visual onset and the appearanc
e of bistable apparent motion displays. In Experiment 1, observes carr
ied out two visual tasks. In the first task, they reported the appeara
nce of a bistable apparent-motion (or Ternus) display. Whether group o
r element motion was perceived depended on the duration of the blank i
nterval between successive frames. In the second task, subjects engage
d in visual search for a prespecified target, and on each trial one el
ement was briefly flickered off and back on. The degree to which that
element captured attention also depended on the duration of the tempor
al gap. The time course of the gap duration effect in the visual searc
h task was very similar to that for the Ternus display. In Experiment
2, we ruled out the possibility that die presence of an abrupt offset
caused the results of Experiment 1. It is argued that the apparent mot
ion and attentional capture phenomena examined here may reflect the op
eration of the same underlying mechanism: in both cases, a sufficientl
y long temporal gap disrupts spatiotemporal continuity, thereby fundam
entally changing the perceived organization of the display.