THE EFFECT OF STIMULUS-PRESENTATION RATE ON SYNTAX TEST-PERFORMANCE IN BRAIN-INJURED ADOLESCENTS

The purpose of this study was to explore how testing procedure influen ces performance after traumatic brain injury, and how this influence v aries as a function of the subject's information-processing abilities. Twelve brain-injured subjects completed three versions of the Listeni ng/Grammar subtest of the Test of Adolescent Language. In the first co ndition, sentences were presented at 2-s intervals, in the second at 4 -s intervals, and in the third at variable intervals controlled by the subject. Scores in each condition were correlated with measures of wo rking memory storage and processing ability. Performance in the 2-s co ndition was significantly influenced by working memory processing abil ity, whereas performance in the 4-s condition was significantly influe nced by working memory storage ability. Both aspects of working memory contributed to performance in the variable condition, although only p rocessing was significant. As a group, subjects with better working me mory processing ability preferred the variable interval condition, whi ch allowed greater flexibility, while subjects with poor processing ab ility found it more difficult. The results are discussed in terms of c linical assessment and intervention.