Comprehension and imitation of syntax following early hemisphere damage.

Twenty-five children with early left (LL = 16) or right (RL = 9) hemisphere damage and 25 age-matched controls were tested on their comprehension and imitation of complex coordinate, passive, and relative clause structures using a matched experimental design. The predominant deficit exhibited by left-injured children was one of significantly impaired imitation coupled with relatively preserved comprehension. For RL subjects the deficit was less pronounced in either comprehension or imitation. Manipulation of surface and configurational features of sentence structure revealed task differences in the pattern of correct performance; however, error strategies observed across the two methodologies were shown to converge in a number of critical ways, as well as to replicate those previously obtained with adult aphasics. The results are interpreted as consistent with an early and continuous left hemisphere specialization for expressive syntax.