VSS 2008 - Vision Science Society 2008 Conference Abstracts

Haladjian & Pylyshyn (2008). Object-specific preview benefit enhanced during explicit Multiple Object Tracking. Vision Sciences Society 2008, Naples, FL.

Object file theory provides a framework for object representations and is demonstrated by an object-specific preview benefit (OSPB) (Kahneman, Treisman & Gibbs, 1992). This framework supports object-based attention by showing that a priming effect for object identity travels with the object in which information initially appeared. The present study explores OPSB effects during Multiple Object Tracking (MOT).

In Experiment 1, four identical circles moved unpredictably in MOT and a preview letter appeared in one circle during the trial. At the end of the trial a test letter appeared and subjects had to indicate whether or not the test letter matched the preview letter (ISIs between preview and test letters varied at 1, 2, and 4 seconds). Subjects’ reaction times in matching letter conditions (i.e., same preview object versus different object) showed a significant OSPB effect of 85 ms (p=.013) for the 1-sec ISI, and this benefit was reduced with longer ISIs. In Experiment 2, two preview letters were presented in two objects. The results exhibited similar patterns as Exp 1 but with a smaller preview effect (63 ms; p=.007). To explore the effect of explicit tracking in Experiment 3, two preview letters were shown within two circles prior to object movement (constant 4-sec ISI). In Block 1, no explicit tracking was required. In Block 2, subjects tracked and identified the circles that had contained letters in addition to judging whether a test letter was one of the preview letters. There was no OSPB effect in the non-tracking condition (replicating the 4-sec ISI results in Experiment 2), but there was a significant preview effect of 108 ms (p=.001) in the explicit tracking condition.

These findings replicate the original OSPB experiments but using the dynamic MOT framework and suggest that explicitly tracking objects extends the OSPB effect.

Kahneman, D., Treisman, A., & Gibbs, B. J. (1992). The reviewing of object files: Object-specific integration of information. Cognitive Psychology, 24(2), 175-219.