Contributions of phonological and semantic short-term memory to sentence processing: Evidence from two cases of closed head injury in children

This paper reports the short-term memory and sentence processing performanc e of two head-injured children who were approximately 10 years of age at th e time of test. The two children were found to have similarly reduced memor y span on a variety of short-term memory tasks relative to age-matched cont rol children, but differing patterns of performance. One child showed reduc ed (or absent) effects of phonological variables, and the other showed redu ced effects of semantic variables. A dissociation in their performance on s entence processing tasks was also observed, with one child showing preserve d comprehension but impaired repetition, and the other child showing the re verse. The results are consistent with previous findings from brain-damaged adults supporting a multiple-components model of short-term memory in whic h phonological and semantic components play different roles in sentence pro cessing. Contrary to our initial hypothesis, the phonological component did not appear to play a more important role in sentence comprehension for chi ldren than for adults. (C) 2000 Acadcmic Press.