Unravelling conversation in aphasia: what is the role of executive functions?

Abstract

It is often observed that people with aphasia have better communicative skills than would be expected, based on their language impairment. One explanation for this is sought in relatively preserved executive control functions. Studies investigating this premise are carried out in experimental or clinical settings using standardised assessments. The ecological validity of these outcomes is questioned.This study describes the relationship between the methods three participants with moderate to severe aphasia use to contribute to conversations and the resources underlying this, in particular executive control functions. This study uses a novel procedure by combining constructs of executive control functions components with conversation analysis elements, in order to describe their behaviours in natural conversations.The three participants show evidence of executive control skills and deficits within their conversations to some extent. These skills are not reflected in the same way on selected standardised assessments of cognitive and language impairment. Results on a test for communicative ability are more in line with their conversation skills. Explanations for this discrepancy are discussed with regards to the definition and assessment of executive control functions. Language impairment affects executive function assessment outcomes and contextual factors such as conversation partner behaviour, sequential knowledge within the conversation and shared knowledge cannot be captured by impairment level assessments.Impairment level assessments, when chosen correctly, provide insight in the reasons for success and failure in real life performance.

Date of Award	31 Dec 2011
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Raymond Wilkinson (Supervisor) & Karen Sage (Supervisor)