Coding processes in normal and learning-disabled children: evidence for modality-specific pathways to the cognitive system.

Abstract

In Experiment 1, normal 10-yr.-olds and 10-yr.-olds diagnosed as learning disabled (LD) were presented with items in visual and auditory modalities for free and cued recall. The LD children had deficits in auditory and/or visual memory. Recall by LD children was worse than for nonimpaired peers only on tasks in the impaired modality, and on cued recall the deficit was confined to recall given a semantic category cue: Recall given perceptual cues was unimpaired. In Experiment 2, presentation-time tasks were used to create a bias toward either perceptual or semantic encoding. The semantic-encoding task removed the modality-specific deficit between LD children and controls. We conclude that deficits in semantically cued recall for children with only one impaired modality had their origins at presentation time. The most parsimonious explanation of these results involves separate pathways linking the auditory and visual modalities to the semantic system.