Abstract
The binding mechanism evaluates incoming information and can integrate several features/objects into a single representation, update existing representations, or create novel object representations. Here, we evaluated the moment-by-moment operations of this mechanism by monitoring the contralateral-delay-activity (CDA, an ERP component indicative of the number of maintained objects). Participants performed the change-detection paradigm, in which colors moved for 1 sec before the retention interval. Motion cues were used in order to indicate either "objecthood" (i.e., 2 colors that moved together) or that the objects were separate (i.e., 2 colors that moved in different directions), creating 4 conditions: two separate objects, four separate objects, 2 color-color conjunction objects, and four separate colors that "met" and became 2 color-color conjunction objects. Across 3 experiments, the results indicated that the color-color conjunction objects were rapidly integrated into bound representations (so that their CDA amplitude was similar to that of two separate colors). In Experiment 1, colors in the "meeting" condition stayed stationary for 100 ms one on top of the other, and the results indicated that the binding mechanism did not integrate them (so that the CDA amplitude was similar to the condition with 4 separate colors), although perceptually these items were identical to the color-color conjunction objects that were integrated into bound representations. In Experiment 2, the meeting colors stayed stationary for 600 ms, one on top of the other after they met, and only high working memory (WM) individuals integrated the items. In Exp 3, the colors met and then moved together for 400 ms. The results indicated that this time, the four colors were integrated into two bound representations (regardless of WM capacity). This demonstrates that the binding mechanism is sensitive to both recency and primacy object information, and that high WM individuals are more likely to override primacy object information.
Meeting abstract presented at VSS 2012