Abstract
To make sense of the world we must track objects as the same persisting individuals over time and motion. Such processing may reflect mid-level ‘object file’ (OF) representations, which track objects over time on the basis of spatiotemporal information while also storing some of their visual features. OFs can be explored via ‘object reviewing’ (OR) effects, which yield ‘object-specific preview benefits’ (OSPBs): discriminations of a dynamic object's features are speeded when an earlier preview of those features occurs on the same object, beyond general priming. Here we ask what information is stored in OFs. OR intrinsically requires storing some features, but previous work has suggested that this information may be abstracted, such that changing low-level features of the probe information (e.g. the font of a letter) has no effect. We explored the limits of such abstraction in a modified OR task with more complex stimuli, asking whether the features stored in OFs are always separable (such that irrelevant features can be changed without cost) or may sometimes be integral (such that varying even irrelevant features yields interference). Two faces appeared briefly on objects which then moved, after which a single probe face (rotated to a partial profile) appeared on one of the objects. Observers judged whether the emotion of the probe face matched either of the initial faces' emotions. These judgments yielded robust OSPBs — but only when the identity of the face itself (independent of the emotion) was also maintained. Identical results were observed with inverted faces, suggesting that these results reflect visual properties, and are not related to specialized categorical processing. In contrast, experiments with simpler stimuli yielded no such differences in OSPBs. We conclude that in some cases OFs store features which are integrally related, such that changes even to task-irrelevant features of the object will foil the maintenance of object-specific information.
Supported by NSF #BCS-0132444