An integrated theory of attention and decision making in visual signal detection.
The simplest attentional task, detecting a cued stimulus in an otherwise empty visual field, produces complex patterns of performance. Attentional cues interact with backward masks and with spatial uncertainty, and there is a dissociation in the effects of these variables on accuracy and on response time. A computational theory of performance in this task is described. The theory links visual encoding, masking, spatial attention, visual short-term memory (VSTM), and perceptual decision making in an integrated dynamic framework. The theory assumes that decisions are made by a diffusion process driven by a neurally plausible, shunting VSTM. The VSTM trace encodes the transient outputs of early visual filters in a durable form that is preserved for the time needed to make a decision. Attention increases the efficiency of VSTM encoding, either by increasing the rate of trace formation or by reducing the delay before trace formation begins. The theory provides a detailed, quantitative account of attentional effects in spatial cuing tasks at the level of response accuracy and the response time distributions.
Smith
Philip L
PL
Department of Psychology, University of Melbourne, Victoria, Australia. philipls@unimelb.edu.au
Ratcliff
Roger
R
D001288:Attention / Q000502:physiology; D003463:Cues; D003657:Decision Making; D006801:Humans; D011582:Psychological Theory; D011930:Reaction Time; D017603:Signal Detection, Psychological / Q000502:physiology; D014796:Visual Perception / Q000502:physiology