Guided Visual Search in Individuals With Mental Retardation

The ability of individuals with mental retardation to focus on task-relevant elements of complex visual arrays and increase visual-search efficiency was investigated. Initial assess-ments of visual-search efficiency were conducted to identify pairs of features for the form and size dimensions for which each participant demonstrated serial search. Subsequently, color was added as a defining feature that could guide search to a subset of the elements in the array. Results indicated that all of the individuals with mental retardation were able to limit attention to the task-relevant items on the guided search task, thus greatly reducing overall target identification times. Results show that individuals with mental retardation can demonstrate sophisticated visual selective attention skills when visual arrays are struc-tured appropriately. The structure of visual arrays is a critical factor that affects not only the detection of similarities and differences among stimuli, but also the acqui-sition of rule-based behaviors (Serna & Carlin, 2001; Soraci, Carlin, & Wiltse, 1998). Although most studies of intelligence-related differences on attentional and cognitive processing tasks are based on the assumption that the sensory information available for higher processing is identical in qual-ity and quantity across groups, our studies have involved no such assumption. Rather, we have em-phasized how the structure of visual arrays facili-tates the detection of relevant stimulus relations, an approach that highlights perceptual/attentional variables rather than cognitive mediation (Soraci, Carlin, & Chechile, 1998). Our general contention is that differential sensitivities to structural prop-erties of visual arrays may underlie a wide range of intelligence-related differences, affecting perfor-mances on tasks considered preattentional in na