Abstract
Objects and ensembles have independently been the focus of much investigation, but it remains to be determined how they are related. We have been investigating the possibility that ensembles function as single units for visual attention and memory – similar to single objects. Here, using one-shot change detection, we find that multiple ensembles can be stored and multiple features can be retained for each ensemble group. We find similar results for individual objects (a replication of Luck & Vogel, 1997). This pattern of results is consistent with the suggestion that an ensemble group behaves as a single item for VWM. Luck & Vogel (1997) demonstrated that memory for items with four features (conjunction) is equivalent to memory for items with a single feature. We replicated this result and adapted this experiment to test the nature of ensembles. Participants were presented with a memory display consisting of either 2 or 4 items (or 2 or 4 ensembles). Both items and ensembles varied on multiple dimensions (e.g., orientation, number, color, size). In the single feature condition, subjects were instructed to attend to a particular feature (e.g., only orientation could change). In the conjunction feature condition, subjects were instructed to attend to all features. After a consolidation period, a test display appeared and participants had to determine whether a change had occurred. The results replicated those of Luck and Vogel (1997) for items with similar results for ensembles. That is, subjects remembered both single features and conjunctions for both individual items and ensembles. We take these results to support the proposal that ensembles are treated in the same manner as individual objects for visual working memory.
Meeting abstract presented at VSS 2013