Spoken words and manual signs as encoding categories in short-term memory for mentally retarded children.

The release from proactive inhibition paradigm was used to test differential encoding of manual signs and spoken words by six severely retarded children. Scores for shift conditions were significantly different from scores for nonshift conditions on the last trial, indicating that manual signs were encoded differently from spoken words for short-term memory storage. Implications of separate encoding categories for the investigation of language processes were discussed.