Experimental manipulation of cognitive control processes causes an increase in communication disturbances in healthy volunteers

BACKGROUND: Although communication disturbances (CD) have been associated with poor cognitive control, it is unclear whether they are associated specifically with poor cognitive control or with poor cognition in general. The current research examined whether (a) two specific components of cognitive control, working memory and interference resolution, were associated with CD, and (b) associations between CD and cognitive control could be accounted for by generalized poor cognitive performance. METHOD: In this study, as healthy volunteers spoke, the level of cognitive demands was experimentally increased, thereby simulating cognitive deficits (i.e. a reduction in the degree to which certain types of cognitive processes could be used for speech). Hence, this research examined whether simulated cognitive deficits would cause an increase in CD. Participants also completed separate cognitive tasks that assessed working memory, interference resolution and general cognitive ability. RESULTS: An increase in working memory demands caused an increase in CD. Moreover, working memory demands interacted with interference resolution demands, with the greatest amount of CD caused by both high working memory and high interference resolution demands. By contrast, increasing another cognitive demand, sustained attention, did not increase CD. Furthermore, performance on separate working memory and interference resolution tasks interacted to predict CD on the experimental speech task. However, performance on a psychometrically matched cognitive task did not predict CD. CONCLUSION: Overall, the current study provides evidence that working memory and interference resolution may be specifically associated with CD and that manipulations of these cognitive control processes can cause an increase in CD.