Abstract
Does the ability to track moving objects through a temporary disappearance depend on how they disappeared? In the target recovery paradigm, participants track multiple targets moving in a display amongst identical distractors and across a momentary blank of the display. Participants must recover the targets after the blank to successfully discriminate them from distractors at the end of a trial. Keane and Pylyshyn (2006) showed superior performance when objects paused during the blank compared to when they continued to move during blank. They suggested this pause-advantage indicated that people do not extrapolate positions of moving objects during tracking. An alternative account of the pause-advantage is that the objects' disappearance causes the positions of the targets to be memorized and then matched to the objects' positions when they reappear. We investigated whether the pause-advantage depended on the strength of the transient produced by the offset of the objects. To increase the strength of the transient, the objects “burned out” by increasing in size just before their offset. To decrease the transient, the objects “faded away” by gradually decreasing in luminance before their offset. The results showed a significant interaction between transient strength (burn out, fade away) and condition (pause, move), F(1,9) = 58.61, p <0.0001. Difference scores constructed by subtracting performance in the move condition from that of the pause condition showed a significantly greater pause-advantage when objects burnt out compared to when they faded away, t(9) = 7.66, p <0.0001. These results demonstrate that stronger transients improve the ability to recover moving objects after they temporarily disappear - burning out is better. Stronger transients may improve the encoding of pre-blank positions to memory. The pause-advantage may stem from processing that occurs because of the blank and may not reflect processing related to tracking.