Span of apprehension in mentally retarded children: an initial investigation

The present investigation is the first to apply Estes' (1965) span of apprehension task to the study of attentional functioning in mentally retarded persons. Detection accuracies of 25 children diagnosed as mildly mentally retarded and 25 non-retarded children were compared under conditions of 100-ms exposure duration, and either two, four, six or eight distractor letters. Significant main effects of subject group and distractor number were found, with no interaction. These results provide converging evidence in support of previous positions that posit a structural deficit in mentally retarded individuals with respect to centrally mediated processing.