This report reviews the state of the literature and opportunities for research related to "executive control function" (ECF) ECF has recently been separated from the specific cognitive domains (memory, language, and praxis) traditionally used to assess patients ECF impairment has been associated with lesions to the frontal cortex and its basal ganglia-thalamic connections No single putative ECF measure can yet serve as a "gold standard" This and other obstacles to assessment of ECF are reviewed ECF impairment and related frontal system lesions and metabolic disturbances have been detected in many psychiatric and medical disorders and are strongly associated with functional outcomes, disability, and specific problem behaviors The prevalence and severity of ECF deficits in many disorders remain to be determined, and treatment has been attempted in only a few disorders Much more research in these areas is necessary

Executive control function: a review of its promise and challenges for clinical research. A report from the Committee on Research of the American Neuropsychiatric Association.

This article considers the scientific process whereby new and better clinical tests of executive function might be developed, and what form they might take. We argue that many of the traditional tests of executive function most commonly in use (e.g., the Wisconsin Card Sorting Test; Stroop) are adaptations of procedures that emerged almost coincidentally from conceptual and experimental frameworks far removed from those currently in favour, and that the prolongation of their use has been encouraged by a sustained period of concentration on “construct-driven” experimentation in neuropsychology. This resulted from the special theoretical demands made by the field of executive function, but was not a necessary consequence, and may not even have been a useful one. Whilst useful, these tests may not therefore be optimal for their purpose. We consider as an alternative approach a function-led development programme which in principle could yield tasks better suited to the concerns of the clinician because of the transparency afforded by increased “representativeness” and “generalisability.” We further argue that the requirement of such a programme to represent the interaction between the individual and situational context might also provide useful constraints for purely experimental investigations. We provide an example of such a programme with reference to the Multiple Errands and Six Element tests. (JINS, 2006, 12, 194–209.)

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The case for the development and use of “ecologically valid” measures of executive function in experimental and clinical neuropsychology

A critical endeavor in every health-related field is the continued development of new technologies and instrumentation for improving diagnosis and treatment. For example, the field of neuroimaging has made astonishing advances with procedures such as functional MRI, MR spectroscopy, and MR diffusion tensor imaging. The field of neuropsychology has also recognized the importance of continually striving to develop new, more sensitive clinical measures. At the same time, the development of new tests or procedures does not guarantee that the instruments represent improvements in diagnosis or treatment. For this reason, ongoing studies of reliability and validity of new diagnostic instruments are also an important part of research in all health-related fields.

Reliability and validity of the Delis-Kaplan Executive Function System: an update.

There has been an increased interest in the structure of and relations among executive functions.The present study examined the factor structure as well as age-related factorial invariance of the Delis—Kaplan Executive Function System (D-KEFS), a widely used inventory aimed at assessing executive functions. Analyses were first conducted using data provided in the D-KEFS technical manual and were then replicated in an independent sample of male early adolescents aged 11 to 16 years. Results revealed a three-factor solution best fit the data across groups and samples; measurement properties appeared to be invariant across age groups for certain loadings and variant for others. The three factors were labeled Conceptual Flexibility, Monitoring, and Inhibition. These findings provide better understanding of the measurement properties of the D-KEFS and contribute to the larger literature on the structure of measures intended to assess executive functions.

http://www.latzmanlab.com/wp-content/uploads/2014/04/Latzman-Markon-2010-Assessment.pdf

The Factor Structure and Age-Related Factorial Invariance of the Delis-Kaplan Executive Function System (D-KEFS)

The cerebellum has long been considered to be mainly involved in motor function. In the last 20 years, evidence from neuroimaging studies and from investigations of patients with cerebellar lesions has shown that the cerebellum plays a role in a range of cognitive functions. While cerebellar contributions have been shown for learning and memory, the cerebellum has also been linked to higher order cognitive control processes frequently referred to as executive functions. Although it is widely accepted that the cerebellum contributes to cognitive processing, the nature of cerebellar involvement is not well understood. The present paper focuses on the role of the cerebellum in executive processing, reviewing findings derived from neuroimaging studies or from studies investigating deficits related to cerebellar dysfunction. As executive functions cannot be considered as a unitary concept, special emphasis is put on cerebellar contributions to different aspects of executive control such as working memory, multitasking or inhibition. Referring to models derived from motor control, possible mechanisms of cerebellar involvement in executive processing are discussed. Finally, methodological problems in assessing executive deficits in general and in assessing the cerebellar contribution to executive processing in particular are addressed.

Cerebellar involvement in executive control.

This study assessed the effectiveness of Greiffenstein's Reliable Digit Span (RDS) score for the detection of malingered neurocognitive dysfunction. Participants were 54 traumatic brain injury patients referred for neuropsychological evaluation. Twenty-four met the Slick, Sherman, and Iverson criteria for at least probable malingered neurocognitive dysfunction. The control group was composed of 30 patients without external incentive and who thus did not meet the Slick criteria. All patients completed the digit span test as part of either the WAIS-R or WAIS-III. The RDS scores were calculated, and sensitivity, specificity, and predictive power were examined for several cutoffs. Classification accuracy for the RDS was excellent. Issues related to the clinical application of this technique are discussed.

Detecting malingered neurocognitive dysfunction using the reliable digit span in traumatic brain injury

The present study examined the classification accuracy of four potential Wisconsin Card Sorting Test malingering indicators (Bernard and Suhr formulas and two types of Unique responses). Participants were 89 traumatic brain-injury (TBI) patients assigned to malingering and nonmalingering groups on the basis of the Slick, Sherman, and Iversion (1999) criteria. Individual Sensitivities were greater than .33 with acceptable Specificity. Combined Sensitivity for two of the indicators was greater than.60. Overall, this study demonstrated three distinct approaches to the WCST used by probable malingerers. The clinical relevance of these findings and directions for future research are discussed.

Detecting malingered performance with the Wisconsin card sorting test: a preliminary investigation in traumatic brain injury.

Detecting malingered performance on the Wechsler Adult Intelligence Scale. Validation of Mittenberg's approach in traumatic brain injury.

This study examined the factorial structure of the Wisconsin Card Sorting Test (WCST) in normal university students (N = 135) and a mixed clinical sample (N = 139). Two highly stable orthogonal factors were observed accounting for 70 and 21 per cent of the variance, respectively. Factor I was interpreted as reflecting undifferentiated executive function while Factor II may measure cognitive abilities associated with attentional function. This work can serve as the basis for further examination of the construct validity of the WCST and has implications for its use.

Factorial structure of the Wisconsin Card Sorting Test.

This study examined the classification accuracy of the Portland Digit Recognition Test (PDRT) in traumatic brain injury (TBI). It differs from past studies in assigning patients to malingering and control groups on the basis of compensation-seeking status and the presence of external markers for malingering. Sensitivity and Specificity were.77 and 1.00, respectively. Past research comparing compensation-seekers to noncompensation-seekers reported Sensitivities of.33 or lower (Specificity is always high). This study demonstrates that past research has seriously underestimated the Sensitivity of the PDRT and raises questions about the true Sensitivity of other malingering techniques as well.

John A. Crouch

Papers

Detecting malingered neurocognitive dysfunction using the reliable digit span in traumatic brain injury

Detecting malingered performance with the Wisconsin card sorting test: a preliminary investigation in traumatic brain injury.

Detecting malingered performance on the Wechsler Adult Intelligence Scale. Validation of Mittenberg's approach in traumatic brain injury.

Factorial structure of the Wisconsin Card Sorting Test.

Classification accuracy of the portland digit recognition test in traumatic brain injury.