Assessment of executive dysfunction

This chapter focuses on the measurement properties of putative tests of executive dysfunction and on validity information. It reviews the tests ranging from long-standing clinical tests such as verbal fluency and the Wisconsin Card Sorting Test to more recent tests that are more explicitly derived from theory, such as the Cognitive Estimation Task, the Brixton and Hayling Tests, dual task methods, and the Behavioural Assessment of the Dysexecutive Syndrome (BADS). It discusses the issue of the ecological validity of tests and the need to consider a patient's premorbid ability when assessing executive functioning. It also briefly reviews the rating scales and questionnaire methods of assessing executive problems and disability. Executive deficits typically have a much more profound effect on recovery and adjustment than the more circumscribed deficits that arise from posterior lesions. However, the behavioural features of executive dysfunction have proven hard to capture formally. In keeping with the emphasis in this book on the use of quantitative evidence to guide practice, this review focuses on the measurement properties of putative tests of executive dysfunction and on validity information (e.g. data comparing anterior lesion cases with controls or posterior cases are used to calculate effect sizes for commonly used tests). The tests reviewed range from long-standing clinical tests (e.g. verbal fluency and the Wisconsin Card Sorting Test) to more recent tests that are more explicitly derived from theory, such as the Cognitive Estimation Task, the Brixton and Hayling Tests, dual task methods, and the Behavioural Assessment of the Dysexecutive Syndrome (BADS). The issue of the ecological validity of tests is discussed as is the need to consider a patient's premorbid ability when assessing executive functioning. Finally, the rating scales and questionnaire methods of assessing executive problems and disability (e.g., the DEX, PRMQ and FrSBe) are briefly reviewed.