Effect of a changing stimulus on the performance of learning disabled and normal children

The effect of stimulus complexity on the performance of 30 learning disabled and 30 normal Caucasian children (age range 10- to 11.6-year-olds) was compared. Reaction time and response patterns were analyzed separately using a three-factor analysis of variance design, with repeated measures over the last factor. The dependent variables were analyzed over both changing and constant conditions. Under the changing condition, colored squares of the 3 by 4 stimulus matrix were assigned at random on every trial. Under the constant condition the colored squares remained in the same position on every trial. The results support the notion that stimulus complexity affects reaction time for both learning disabled and normal children. No response patterns were shown.