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.     

Will Julia Roberts harm Nicole Kidman? Semantic priming effects during face naming

Three experiments are reported, which examine whether face naming is vulnerable to semantic competition in a similar way to object naming. Previous experiments with object naming have shown that a related prime picture presented 3 trials before a target picture results in an increase in error rate and naming latencies when compared to unrelated prime conditions. The experiments here use the same paradigm, with errors as the main dependent variable. In Experiment 1, the prime and target faces were from the same occupational category (e.g., politicians, actors), and in Experiment 2, the primes and target faces were also associated to each other. In Experiment 3, the prime was presented as a name to be read aloud. Unrelated filler stimuli intervened between prime and target. In all experiments, there was a reduction in target-naming errors in the related conditions, and in Experiment 3 this was shown to be largely a reduction in naming failures. The results suggest that related name representations for famous people are not activated in parallel and in competition, and that there is some evidence for a relatively long lasting facilitatory effect. These results require some modification to any serial account of face naming to differentiate it from the generally well-established serial account of object naming.     

Understanding spatial diagram structure: an analysis of hierarchies, matrices, and networks

diagrams are powerful tools for comprehension and problem solving in diverse contexts. Two studies examined the structural properties of (i.e., applicability conditions for) three interrelated spatial diagrams—hierarchies, matrices, and networks. College students from two groups with distinct educational backgrounds and learning histories—advanced computer science students and representative undergraduates—rated the diagnosticity of the hypothesized applicability conditions for each of the 3 diagrams. The results validated 24-26 of the 30 hypothesized applicability conditions and provided evidence regarding the relative importance, or diagnosticity, of the validated properties for each type of diagram. A different set of properties was identified as most highly diagnostic for each type of diagram, indicating that the three spatial diagrams are optimized to serve different representational functions: The matrix stores static information about the kind of relation that exists between pairs of items in different sets, the network conveys dynamic information by showing the local connections and global routes connecting the items being represented, and the hierarchy depicts a rigid structure of power or precedence relations among items. The quantitative and qualitative differences in representational knowledge due to educational background are discussed.