Constructing representations of spatial location from briefly presented displays

Spatial memory and reasoning rely heavily on allocentric (often map-like) representations of spatial knowledge. While research has documented many ways in which spatial information can be represented in allocentric form, less is known about how such representations are constructed. For example: Are the very early, pre-attentive parts of the process hard-wired, or can they be altered by experience? We addressed this issue by presenting sub-saccadic (53 ms) masked stimuli consisting of a target among one to three reference features. We then shifted the location of the feature array, and asked participants to identify the target’s new relative location. Experience altered feature processing even when the display duration was too short to allow attention re-allocation. The results demonstrate the importance of early perceptual processes in the creation of representations of spatial location, and the malleability of those processes based on experience and expectations.     

A Comparison of Suicide and Undetermined Deaths in Psychiatric Patients

ABSTRACT: Those people who had previously been patients of the Department of Mental Health of Missouri who died in the three year period 1972 through 1974 and whose deaths were designated as suicide or “undetermined whether purposely or accidentally inflicted,” were identified by matching statewide death tapes against the DMH data base. The demographic characteristics of the two groups are compared to ascertain if the members of the undetermined group are essentially similar to the suicides, as has frequently been hypothesized. It is found that, in general, the similarities are in areas which would not have had a direct influence on the medical examiner/coroner's verdict, whereas, the differences do highlight areas which could cause an indecisive verdict. The significance of the undetermined deaths is discussed.     

Virtual struggles?

Resisting the Virtual Life: The Culture and Politics of Information, edited by James Brook and Iain A. Boal. San Francisco: City Lights, 1995, 278 pp. + photos, $15.95 pb.