The research proposed here investigates age-related changes in the construction and use of syntactic structures in sentence comprehension. We distinguish between a skilled parser that incrementally assigns structure and meaning in most situations and a controlled processor that contributes to comprehension when the skilled parser fails to yield a meaning that the comprehender needs. We hypothesize that the skilled parser utilizes long term working memory and the controlled processor utilizes short term working memory. We hypothesize that age has no effect on the skilled system but that age-related changes in short term working memory negatively affect the controlled processor. The research proposed here will test predictions of this theory using detailed and novel analyses of eye fixations in reading, self-paced reading times and the time course of the ability to discriminate acceptable and unacceptable sentences under conditions that provide information about how items are retrieved in memory (the speed accuracy trade-off technique applied in sentences). Its theoretical significance lies in the understanding of the memory systems that support comprehension, age effects in comprehension and age-related changes in memory that lead to these effects.
The public health significance of this work is related to a better understanding of areas of age-related preservation and decline in an important language function, which can lead to better communication with older individuals. The work may also lead to interventions that improve declining comprehension abilities in aging.
