Task-irrelevant visual motion and flicker attenuate the attentional blink

Our reduced ability to correctly report two sequentially presented targets is seen in the robust effect known as the attentional blink (AB; Raymond, Shapiro, & Arnell, 1992). One recent report (Olivers & Nieuwenhuis, 2005) strikingly reveals the AB to be virtually abolished when non-task-demanding music occurs in the background. The authors suggest that a diffuse attentional state is the mediating factor. Here, we seek to broaden the finding’s generality by determining if task-irrelevant visual motion and flicker also attenuate the AB. In our experiments, the AB task was presented together with a background field of moving dots that could moveaway from ortoward the central AB task, or flicker. In the control condition, the dots remained static. The AB was attenuated—though to different degrees—in all experimental conditions, but not in the static condition. Our findings add to the generality of the previous conclusions, and we emphasize an account based on the overallocation of attention.     

Spatial updating relies on an egocentric representation of space: Effects of the number of objects

Models of spatial updating attempt to explain how representations of spatial relationships between the actor and objects in the environment change as the actor moves. In allocentric models, object locations are encoded in an external reference frame, and only the actor’s position and orientation in that reference frame need to be updated. Thus, spatial updating should be independent of the number of objects in the environment (set size). In egocentric updating models, object locations are encoded relative to the actor, so the location of each object relative to the actor must be updated as the actor moves. Thus, spatial updating efficiency should depend on set size. We examined which model better accounts for human spatial updating by having people reconstruct the locations of varying numbers of virtual objects either from the original study position or from a changed viewing position. In consistency with the egocentric updating model, object localization following a viewpoint change was affected by the number of objects in the environment.