IS THE PHONOLOGICAL LOOP RESPONSIBLE FOR INTELLIGENCE-RELATED DIFFERENCES IN FORWARD DIGIT SPAN

Children with mild mental retardation were compared with CA-matched an d verbal-age-matched children without mental retardation on a forward digit span task. Forward digit span is typically used as a measure of the phonological loop (Baddeley, 1986). We hypothesized that intellige nce-related differences in forward digit span are largely due to centr al executive functioning rather than phonological loop functioning. Re sults showed that the highly significant group difference in forward d igit span was reduced to nonsignificance when a measure of central exe cutive functioning was covaried out.