Spatial Attention Is Attracted in a Sustained Fashion toward Singular Points in the Optic Flow
Figure 7
Expansion but not contraction influences the speed of change detection
. (A) For Experiment 2, a 0.6 sec movie expanded or contracted with the associated FOE or FOC located either at the corner of the same quadrant as the change or at the opposite corner (in this example, the car on the bottom right disappeared). After a 0.28 sec blank period, a stationary image with a single noticeable change from the last frame of the movie was presented for 0.6 sec, followed by another 0.28 sec blank. This loop was repeated until subjects responded. (B) The cumulative detection probability as a function of RT (log scale). When the FOE was close to the location of the change, detection was facilitated, while when the FOE was far away, it interfered with change detection. Contraction did not affect change detection, compared to the control stationary condition. (Inset) Mean RT (error bars are for s.e.m.).