Concept Of Executive Function Research Articles

A microworld simulation of dynamic cognition as a test of executive function

ABSTRACT Introduction The lack of consensus regarding the nature or composition of executive functioning (EF) has led to a proliferation of executive tasks to assess the concept. Many do agree however that the theoretical concept of EF is a holistic one, leading us to consider whether it would be beneficial to assess EF in a more holistic manner. We explore how well a computerized simulation of dynamic cognition – that reproduces the context of real-world complex decision-making – can predict performance on nine classical neuropsychological tasks of EF. Methods A sample of 121 participants completed all tasks, and canonical correlations were used to assess the nine tasks as predictors of the three simulation performance metrics to evaluate the multivariate-shared relationship between the two variable sets: executive functions and dynamic cognition. Results Results show that a substantial amount of variance in two indices of dynamic cognition can be explained by a linear combination of three key types of neuropsychological tasks (planning, inhibition, working memory), with a larger contribution from the planning tasks. Conclusion Our findings suggest that tasks of dynamic cognition could augment traditional, separate tests of EF, offering benefits in terms of parsimony, ecological validity, sensitivity, and computerized delivery.

A continuum of executive function deficits in early subcortical vascular cognitive impairment: A systematic review and meta-analysis.

ABSTRACT.Background.Subcortical Vascular Cognitive Impairment (SVCI) is a clinical continuum of vascular-related cognitive impairment, including Vascular Mild Cognitive Impairment (VaMCI) and Vascular Dementia. Deficits in Executive Function (EF) are hallmarks of the disorder, but the best methods to assess this function have yet to be determined. The insidious and almost predictable course of SVCI and the multidimensional concept of EF suggest that a temporal dissociation of impairments in EF domains exists early in the disorder.Objective:This study aims to review and analyze data from the literature about performance of VaMCI patients on the most used EF tests through a meta-analytic approach.Methods:Medline, Web of Knowledge and PsycINFO were searched, using the terms: “vascular mild cognitive impairment” OR “vascular cognitive impairment no dementia” OR “vascular mild neurocognitive disorder” AND “dysexecutive” OR “executive function”. Meta-analyses were conducted for each of the selected tests, using random-effect models.Results:Systematic review showed major discrepancies among the results of the studies included. Meta-analyses evidenced poorer performance on the Trail-Making Test part B and the Stroop color test by VaMCI patients compared to controls.Conclusion:A continuum of EF impairments has been proposed in SVCI. Early deficits appear to occur in cognitive flexibility and inhibitory control.

Treatment Options for Executive Dysfunction

The concept of executive function is a so-called umbrella concept, so that it includes many different and in some cases mutually contradictory higher-level organizational abilities such as planning, monitoring, inhibition and control of action. Typically, the cause of an executive dysfunction is an underlying lesion in the prefrontal cortex or subcortical regions. Deficits in executive functions appear in the fields of cognition as well as behavior. Diagnosis requires the use of a wide-ranging repertoire of tests and questionnaires making it a time-consuming process. Different therapeutic approaches addressing the diverse symptoms of executive dysfunction, both positive and negative, are available. These include modification and manipulation of the environment and practice of cognitive repetitive procedures. The former are implemented particularly in cases of severely impaired persons. The latter are used in persons in whom cognitive dysfunctions are the dominating symptoms of the disorder.The operational area of therapeutic approaches using paper and pencil as well as computer programs limits them to treatment of cognitive dysfunction. If behavioral disturbances dominate the clinical picture, other procedures should be used.The effectiveness of cognitive therapy of executive dysfunction is well demonstrated according to the criteria of evidence-based medicine (EBM).

Teachers as Air Traffic Controllers: Helping Adolescents Navigate the Unfriendly Skies of Executive Functioning

ABSTRACTThe purpose of this article is to familiarize teachers with the concept of executive functioning and to provide them with a collection of strategies that they can use to help support middle and high school students with planning, organization, task-initiation, and impulse control.

Restoring the integrative value to the notion of executive function. Commentary on: “Advancing understanding of executive function impairments and psychopathology: bridging the gap between clinical and cognitive approaches”

Restoring the integrative value to the notion of executive function. Commentary on: “Advancing understanding of executive function impairments and psychopathology: bridging the gap between clinical and cognitive approaches”

The Association of Specific Executive Functions and Falls Risk in People with Mild Cognitive Impairment and Early-Stage Dementia

Background/Aims: Impairment in executive function is associated with a heightened risk for falls in people with mild cognitive impairment (MCI) and dementia. The purpose of this study was to determine which aspects of executive function are associated with falls risk. Methods: Forty-two participants with a mean age of 81.6 years and a diagnosis of MCI or mild dementia completed five different executive function tests from the computerised CANTAB test battery and a comprehensive falls risk assessment. Results: A hierarchical regression analysis showed that falls risk was significantly associated with spatial memory abilities and inhibition of a pre-potent response. Conclusion: The concept of executive function may be too general to provide meaningful results in a research or clinical context, which should focus on spatial memory and inhibition of a pre-potent response.

Executive Function and Dysfunction

Article AbstractBecause this piece does not have an abstract, we have provided for your benefit the first 3 sentences of the full text.If you are a child clinician, then you have undoubtedly spent time wrestling with the concept of executive functions. From Baddeley's first description of executive control, the term has quickly evolved to describe a host of skills that support behavioral and emotional regulation. Executive dysfunction has become the term used to describe the behavior observed across a wide range of psychiatric and neurodevelopmental disorders.

Mental health and social functioning in early treated Phenylketonuria: The PKU-COBESO study

This article presents a new Dutch multicenter study (“PKU-COBESO”) into cognitive and behavioral sequelae of early and continuously treated Phenylketonuria (PKU) patients. Part of the study sample will consist of young adult PKU patients who have participated in a large neuropsychological study approximately 10years ago, when they were 7-to-15-year-olds (Huijbregts et al., 2002 [1]). Their neurocognitive development will be mapped in association with their earlier and continued metabolic history, taking into account possible changes in, for instance, medication.A second part of the sample will consist of PKU patients between the ages of 7 and approximately 40years (i.e., born in or after 1974, when neonatal screening was introduced in The Netherlands), who have not participated in the earlier neuropsychological study. Again, their cognitive functioning will be related to their metabolic history. With respect to aspects of cognition, there will be an emphasis on executive functioning. The concept of executive functioning will however be extended with further emphasis on the impact of cognitive deficits on the daily lives of PKU patients, aspects of social cognition, social functioning, and behavior/mental health (i.e., COgnition, BEhavior, SOcial functioning: COBESO).In addition to a description of the PKU-COBESO study, some preliminary results with respect to mental health and social functioning will be presented in this article. Thirty adult PKU patients (mean age 27.8, SD 6.4) and 23 PKU patients under the age of 18years (mean age 11.0, SD 3.3) were compared to 14 (mean age 26.9years, SD 5.9) and 7 matched controls (mean age 10.5, SD 2.6) respectively, with respect to their scores on the Adult Self-Report or Child Behavior Checklist (measuring mental health problems) and the Social Skills Checklist or Social Skills Rating System (measuring social skills).Whereas there were very few significant group differences (except for mental health problems in the internalizing spectrum for adult PKU patients), possibly due to the small control groups, several significant associations between mental health problems and Phe levels were observed for the PKU patients. Childhood Phe levels and internalizing problems for adult PKU patients were related; concurrent Phe was associated with both internalizing and externalizing behavioral problems for those under the age of 18. These preliminary results underline the importance of early dietary adherence.

Executive functions: what they are, how they work, and why they evolved

Problems with the Concept of Executive Functioning. The Extended Phenotype: A Foundation for Modeling Executive Functioning. Executive Functioning as an Extended Phenotype. The Instrumental-Self-Directed Level. The Methodical-Self-Reliant Level. The Tactical-Reciprocal Level. The Strategic-Cooperative Level. The Extended Utilitarian Zone. Implications for Understanding Executive Functioning and Its Disorders. Implications for the Assessment and Clinical Management of Deficits in Executive Functioning. References. Index.

Executive control: balancing stability and flexibility via the duality of evolutionary neuroanatomical trends

The concept of executive functions has a rich history and remains current despite increased use of other terms, including working memory and cognitive control. Executive functions have sometimes been equated with functions subserved by the frontal cortex, but this adds little clarity, given that we so far lack a comprehensive theory of frontal function. Pending a more complete mechanistic understanding, clinically useful generalizations can help characterize both healthy cognition and multiple varieties of cognitive impairment. This article surveys several hierarchical and autoregulatory control theories, and suggests that the evolutionary cytoarchitectonic trends theory provides a valuable neuroanatomical framework to help organize research on frontal structure-function relations. The theory suggests that paleocortical/ventrolateral and archicortical/dorsomedial trends are associated with neural network flexibility and stability respectively, which comports well with multiple other conceptual distinctions that have been proposed to characterize ventral and dorsal frontal functions, including the "initiation/inhibition," "what/where," and "classification/expectation" hypotheses.

Executive Function and Type 2 Diabetes: Putting the Pieces Together

The devastating impact of type 2 diabetes mellitus (DM) on vascular, renal, retinal, and peripheral nerve functions has been well documented. However, there is also evidence that older adults with this disease exhibit impairments in the planning, coordinating, sequencing, and monitoring of cognitive operations, collectively known as executive function. Although poorly understood, disturbances in executive function, particularly within the dimension of time sharing, may contribute to the gait abnormalities and increased risk for falls, functional impairments, and disabilities associated with type 2 DM. However, the relationships between executive function and functional abilities remain poorly understood in this population. Current neuropsychological research regarding the concept of executive function is presented here as a framework upon which to examine the integrity of this critical cognitive entity in adults with type 2 DM. The pathophysiological mechanisms thought to underlie diabetes-related executive dysfunction are explored, and the possible contributions of executive deficits to impairments in gait and function observed in older people with type 2 DM are summarized. Finally, a brief discussion of dual-task assessment and intervention strategies that may facilitate the care and rehabilitation of the growing population of patients with type 2 DM is provided.

A multiperspective approach to the conceptualization of executive functions

The concept of executive function (EF) is deemed unclear and difficult to operationalize. We use a multiperspective approach to quantify and reduce the current proliferation of EFs. A literature review of 60 studies identified 68 subcomponents of EF: Through objective statistical techniques, these terms were reduced to 18 by removing semantic overlap (using latent semantic analysis) and psychometric overlap (using hierarchical cluster analysis). However, still such a large number of functions lacks parsimony. We therefore revisit the concept of EF and suggest that the many proposed subcomponents are not functions per se but rather a number of task-specific behaviors.

Dimensions of the Dysexecutive Questionnaire (DEX) examined using Rasch analysis

Executive dysfunction is very broad term used to capture a range of interacting high-level cognitive, emotional and behavioural difficulties, commonly seen after acquired brain injury (ABI). Many argue that the concept of executive functioning should be subdivided into several separate dimensions. In this study we explore the dimensional structure of a tool designed to assess level of executive functioning, the Dysexecutive (DEX) Questionnaire (Burgess, Alderman, Wilson, Evans, & Emslie, 1996), in order to inform theoretical conceptualisations of executive functioning and improve measurement precision in rehabilitation centres. Rasch analysis was undertaken on the responses of 363 people with ABI to the DEX. Overall, the questionnaire did not perform as a unidimensional, interval-level scale of executive functioning, suggesting that it measures more than one psychological construct. Most subscales previously proposed using factor analysis, including those suggested in the DEX manual, did not perform as unidimensional interval-level scales either. Several new subscales in keeping with theoretical conceptualisations of the different dimensions of executive functioning are proposed, alongside suggestions for revision of the wording and scoring of some of the items in the DEX. These results provide a platform for future evaluation of executive function rehabilitation programmes.

Seeking the Everyday Meaning of Autonomy in Neurologic Disorders

THE SOCRATIC APHORISM that the unexamined life is not worth living and dictums like “Know thyself” remind us of the centrality of self-understanding in the history of philosophical reflections on autonomy. These traditional concerns with autonomy may seem far removed from the neurologic impairments to which Joel Anderson and Warren Lux draw our attention. Nonetheless, Anderson and Lux have provided an important discussion that links the traditional philosophical commitment to selfknowledge with an account that parses these concepts in the context of neurologic disorders. Theirs is a potentially productive approach for improving our understanding of autonomy, one that Emilio Mordini and I advocated in a paper entitled, “Autonomy and the Ethics of Neurosurgery” (Agich and Mordini 1998, 54). We argued that the focus of bioethics on issues such as informed consent misses the more challenging and potentially fruitful collaboration that neurosurgery and neurology affords for advancing the philosophical understanding of the conditions of autonomy. The challenge is in the integration of concepts used in one context of meaning with other domains of discourse. A good example of the challenges embedded in pursuing this kind of project can be found in Anderson and Lux’s discussion of the concept of accurate self-assessment. Anderson and Lux argue that accurate selfassessment is a requirement for one to act autonomously. On first hearing, this phrase sounds unsurprising and consistent with standard approaches that assume a higher degree of awareness of one’s capacities. Their characterization, however, derives from their observations of cases involving severe neurologic impairments, which point to more basic processes than the reflective awareness or knowledge that is often assumed. Paradoxically, the language of accurate self-assessment sounds remarkably like an intellectual function. It appears to fall squarely within the traditional philosophical tendency to define autonomy in terms of ego-centered, intellectual functions involving relatively high-level reflective capacities. Despite their terminology, Anderson and Lux stress that their account requires a type of reflexivity that is not the same as self-conscious reflection understood in the highest degree. They stress this in a number of places. For example, they see the neurologic concept of executive function as involving basic feedback mechanisms that are “broadly isomorphic with capacities associ-

Measuring Executive Functions in Childhood: Problems and Solutions?

In this review we outline some of the current issues surrounding the measurement of executive function (EF) in children. Beginning with the theoretical background to the concept of EF we then review the difficulties in measuring EF in adult populations, and argue that these difficulties may, at least in part, be overcome when working with children, so that developmental studies of EF may provide special insights into the organisation of EF. Next, we review three research areas that have attracted considerable interest in childhood EF: (i) developmental disorders; (ii) new methodologies for investigating the normative development of EF (including three task batteries – CANTAB, TEA‐Ch and MARS); and (iii) the relationship between Theory of Mind (ToM) and EF. Finally, we consider what progress has been made so far in the fractionation of EF into component processes, and what remains to be done to achieve this important goal.