INFLUENCE OF PRIOR PICTORIAL CONTEXT ON SENTENCE COMPREHENSION IN OLDER VERSUS YOUNGER APHASIC SUBJECTS

Deficits in language comprehension have been observed in older individ uals, particularly affecting comprehension of complex syntactic constr ucts such as passive sentences. Aphasic adults display a qualitatively similar pattern, with passive constructions being more difficult to c omprehend than active constructs. Various types of context have been f ound to influence auditory comprehension in aphasia, including the com prehension of passive constructions. In particular, visual stimulation has been observed to facilitate the comprehension of complex spoken m essages for many aphasic adults. However, it is unclear whether presen ting visual stimuli prior to auditory stimuli is more facilitative tha n initially presenting auditory stimuli. Furthermore, in light of repo rted age-related declines in comprehension of passive constructions, i t is unknown whether age affects the influence of visual stimulation a nd, if so, when these effects are more facilatory. In this investigati on the influence of pictorial stimulation on sentence comprehension wa s examined for 12 older and 10 younger aphasic adults. The two aphasic groups were tested on the comprehension of reversible active and pass ive sentences presented in isolation or in paragraphs. Subjects heard the stimuli prior to or after seeing accompanying pictures which were black-and-white line drawings depicting the two possible subjects-obje ct relations presented in the reversible sentences. The older aphasic subjects were significantly more accurate than the younger subjects in the post-exposed visual condition, as well as on isolated passive sen tences in which there was no paragraph context. In both of these condi tions the availability of contextual information (visual-pictorial or auditory-linguistic) was minimized. In the other conditions in which s upportive visual-pictorial or auditory-linguistic context was provided prior to the presentation of the target sentences, the older and youn ger groups demonstrated similar levels of impaired performance. The re sults are discussed relative to the ageing process, allocation of reso urces, and working memory capacity.