Deficits in language comprehension have been observed in older individuals, particularly affecting comprehension of complex syntactic constructs such as passive sentences. Aphasic adults display a qualitatively similar pattern, with passive constructions being more difficult to comprehend than active constructs. Various types of context have been found to influence auditory comprehension in aphasia, including the comprehension of passive constructions. In particular, visual stimulation has been observed to facilitate the comprehension of complex spoken messages for many aphasic adults. However, it is unclear whether presenting visual stimuli prior to auditory stimuli is more facilitative than initially presenting auditory stimuli. Furthermore, in light of reported age-related declines in comprehension of passive constructions, it is unknown whether age affects the influence of visual stimulation and, if so, when these effects are more facilatory. In this investigation the influence of pictorial stimulation on sentence comprehension was examined for 12 older and 10 younger aphasic adults. The two aphasic groups were tested on the comprehension of reversible active and passive 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-object 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 sentences in which there was no paragraph context. In both of these conditions the availability of contextual information (visual-pictorial or auditory-linguistic) was minimized. In the other conditions in which supportive visual-pictorial or auditory-linguistic context was provided prior to the presentation of the target sentences, the older and younger groups demonstrated similar levels of impaired performance. The results are discussed relative to the ageing process, allocation of resources, and working memory capacity.
