Narrative discourse production in adults: Relationships with age and executive functions

The use of discourse analysis has become increasingly popular in the study of neurogenic-communication disorders across the adult life span. However, in order for these measures to be clinically relevant, there is a need for more information regarding typical discourse behavior and a better understanding of the sources of variability that impact performance. To this end, the present investigation sought to explore the relationships between goal-directed aspects of narrative macrostructure, specifically story grammar (SG), and age-related differences. Theoretically similar aspects of goal-directed behaviors in the form of standardized executive function (EF) measures were employed in an attempt to identify common performance patterns between EF, story grammar, and aging. Forty-six neurologically intact adults between the ages of 18–98 were studied. Two narrative production tasks were utilized, story retelling and story generation. Results indicated that two story grammar measures, proportion of T-units in episode structure in the retell condition and number of complete episodes in the generation condition, were correlated with participant age and a number of linguistically-based and non-linguistically-based executive function measures. Hierarchical cluster analysis based upon participant story grammar measures demonstrated significant differences between an oldest cluster (mean age 72.3) and a youngest cluster (mean age 49.49) although neither cluster was significantly different from the middle-aged cluster (mean age 61.73). Rotated factor patterns of the correlated SG and EF variables indicated that two distinct factors, output-fluidity and organization-efficiency, grouped different measures of goal-directed managerial knowledge. The data from the present study are consistent with previous findings and suggest that narrative discourse performance is different across the age range studied. Story grammar measures appear to be equally related to linguistic and non-linguistic EF measures and may provide an ecologically valid measure of executive ability. Additionally, profiles of narrative discourse may provide a more appropriate benchmark of elderly performance when assessing and treating adults with cognitive communicative impairments.