Treatment and generalization of complex sentence production in agrammatism

The present study applies single-subject experimental design to examine (a) the acquisition and generalization of complex sentence production in agram matism using linguistic Specific Treatment (LST) and (b) the utility of syn tactic theory in guiding hypotheses of treatment effects. LST trains constr uction and production of complex sentence structures. Four sentence types w ere selected for study: object clefts and object-extracted matrix and embed ded questions (which are noncanonical with wh-movement), and embedded activ es (which are canonical with no overt movement). All sentences contain over t material in the complementizer phrase (CP) of the syntactic tree. Three o f five participants (1, 2, and 3) demonstrated generalization from object c left treatment to production of matrix questions. Thus, LST was effective i n improving their ability to generate less complex sentences with wh-moveme nt. Once production of object clefts and matrix questions was acquired, all 5 participants demonstrated generalization from treatment to improved prod uction of embedded questions and/or embedded actives. This generalization i nvolved improved ability to generate embedded clausal structure to form com plex sentences but continuing inability to express overt material in CP. Fi nally, direct treatment for embedded questions did not result in accurate p roduction of embedded actives or vice versa. There were no trends across pa rticipants toward improved production of morphosyntactic behaviors in narra tive. Persons 1,2, and 3 showed generalization to increased informativeness and efficiency of expression and were judged by independent listeners to i mprove in content, coherence, and Fluency of spontaneous production. The re maining two participants showed no change or a decline in performance in na rrative language production (4 and 5, respectively). These participants dem onstrated more severe Broca's aphasia at pretesting compared to Persons 1, 2, and 3, with greater impairments in auditory comprehension, naming, and r eading. Etiology and size of lesion did not appear to account for the diffe rent behavioral patterns. This study supports the use of LST, which applies syntactic theory to predict patterns of generalization, as an effective tr eatment approach.