Enhancing Visual Search Efficiency in Individuals with Mental Retardation
The purpose of this project is to provide information about the basic visual processing skills of individuals with mental retardation. Findings will inform the design of remediation procedures that rapidly establish appropriate observing behaviors and stimulus control. Our previous studies of visual search indicated that individuals with mental retardation searched more slowly than individuals without mental retardation, sometimes serially searching for targets that were immediately evident to individuals without mental retardation. Our recent completed studies have indicated that the search efficiency of individuals with mental retardation can be improved dramatically by targeted manipulations of the structure of visual arrays. Two Guided Search studies have shown that individuals with mental retardation can limit attention to task-relevant elements in a visual array while inhibiting attention to task-irrelevant stimuli. This goal-directed allocation of attention indicates sophisticated control of observing behaviors by individuals with mental retardation that leads to significant decreases in target identification times. In a series of Attentional Capture tasks, we found that individuals with mental retardation are more susceptible to distraction by highly-salient stimuli in the very early stages of visual processing than individuals without mental retardation. Further, results indicated that the magnitude of the attentional capture effect varied depending upon the disparity between the target and distractor stimuli and the perceptual strength of the "capture" stimulus.
In followup work, we will augment our behavioral studies of these processes through utilization of eyetracking technology. This technology will allow us to assess observing behaviors in real time such that we can test inferences regarding the basis of the observed intelligence-related differences. Further, we will expand our work to include analysis of visual search behaviors in real-life scenes. The outcomes of these studies will inform the design of training procedures that "guide" attention to critical stimuli in visual arrays and decrease distraction by irrelevant elements such that stimulus control, and subsequent learning, can be established more rapidly and successfully.