SEMANTIC PROCESSING IN RETARDED READERS AND NON-READERS USING A STROOP COLOR NAMING PARADIGM

A Stroop color naming paradigm was used to examine the level of semantic processing in retarded adults in two experiments. The Stroop test has been found a sensitive measure of automaticity of reading and spontaneous semantic processing. Subjects chosen were either readers or non-readers. In Experiment 1, printed words and arbitrary signs were taught for the colors red, green and blue to examine the differential effects on each group of training a three item vocabulary. Each group was tested for Stroop effects at three stages of sign and word training: untrained, trained, and overtrained. It was assumed that readers would show Stroop effects for words without training and that non-readers would not. Neither group was expected to show Stroop effects for untrained signs but were expected to show more Stroop effects in later stages of training. Based on previous studies of retarded individuals learning sign word vocabularies, it was predicted that learning signs would produce semantic processing. The results of Experiment 1 showed a substantial Stroop effect for readers with words in all stages of training. Readers also showed a Stroop effect for signs but not until the overtraining stage of training. Non-readers showed no Stroop effect in any condition for words or signs. Experiment 1 contained arbitrarily mixed congruent and incongruent trials. Experiment 2 was designed to provide a more sensitive measure of Stroop interference. Whereas in the first experiment, congruent and incongruent trials were presented in a randomized order, in Experiment 2 the two types of trials were presented in blocks, a method that has been found to increase Stroop effects. Experiment 2 results differed from those of Experiment 1 in demonstrating significant Stroop effects in both readers and non-readers.