Developmental recall lag in learning-disabled children: perceptual deficit or verbal mediation deficiency?
To investigate the development of mediational deficiencies in verbal and nonverbal visual short-term memory of learning-disabled children, the recall task of Atkinson, Hansen, and Bernback was administered to learning-disabled children in two experimental conditions. In Experiment 1 no significant differences on nonverbal short-term memory recall between normal and learning-disabled children were found. Similar recall responses (e.g., middle response bias, primacy effects, and recency effects) were found for both groups. Nonverbal recall was comparable for disabled and normal children as suggested by stimulus content and association scores. Experiment 2 found that while the effects of overt rehearsal on pretrained labels on learning-disabled children's recall was negligible, labels provided superior recall for normal children. Results suggested that learning-disabled children suffer from a verbal mediational deficiency consistent with Flavell's (1970) mediation deficiency hypothesis.