Textual cohesion in oral narrative and procedural discourse: the effects of ageing and cognitive skills

Knowledge of the discourse performance of non-brain-damaged individuals is critical not only for its differentiation from disordered expression but also for more accurate models of ageing and communication. The effect of ageing and cognitive skills on the cohesive adequacy of discourse has, until now, presented a confusing and ambiguous picture.

To examine comprehensively the effects of both age and cognitive skills on the discourse cohesion of 32 non-brain-damaged males divided into four age groups.

A large body of narrative and procedural samples (394 samples) was elicited from the participants. Their cognitive skills were determined using three tests, whilst their discourse cohesion was analyzed and correlated with the cognitive test results.

This extensive investigation of ageing effects on discourse cohesion and their relationship to cognitive behaviour did not provide neat generalizable results. It showed that ageing significantly increases the number of cohesive errors and reduces the quantity of referential ties in picture-sequence narratives. The changes with age were limited to two aspects of cohesion and not linear across age groups. The participants' cognitive skills declined with age. Correlations between some cognitive tests and certain cohesive changes suggest co-occurring deficits rather than a causal explanation of cohesive decline with age.

With ageing there are increased cohesive errors and decreased referential ties, co-occurring with declining cognitive skills. This study yields important guidance for future research, suggesting that picture-sequence narrative is the most effective tool for clinical evaluation of discourse, but also that findings from one discourse sample may be misleading.