Nick Alderman

Bio: Nick Alderman is an academic researcher from Swansea University. The author has contributed to research in topics: Acquired brain injury & Poison control. The author has an hindex of 27, co-authored 58 publications receiving 4657 citations. Previous affiliations of Nick Alderman include Northampton Community College.

Behavioural Assessment of the Dysexecutive Syndrome

Abstract: Assessments are carried out in order to answer questions. Consequently, the nature of the question determines the assessment procedure. So we would use different tests and procedures for testing out a theoretical model than we would for trying to predict the likelihood of successful return to work for a brain-injured patient. An example of the former is the work of Baddeley, Logie, Bressi, Della Sala, and Spinnler (1986), who were trying to support or refute their hypothesis that patients with Alzheimer’s disease had a deficit in the central executive component of the working memory model (Baddeley & Hitch, 1974). An example of the latter is Shallice and Burgess’s (1991) six elements test which requires participants to plan and organise their activity over a 15-minute period while following certain rules. Mayes (1986) discusses the different concerns of researchers and clinicians with regard to memory assessments but his views are equally relevant to assessments of executive functioning. When thinking about frontal lobe or executive functioning clinicians are likely to be concerned with answering such questions as:1. Does this person have cognitive impairments that are typically associated with the Dysexecutive syndrome (DES)?

The ecological validity of tests of executive function.

Abstract: Ninety-two mixed etiology neurological patients and 216 control participants were assessed on a range of neuropsychological tests, including 10 neuropsychological measures of executive function derived from 6 different tests. People who knew the patients well (relatives or carers) completed a questionnaire about the patient's dysexecutive problems in everyday life, and this paper reports the extent to which the tests predicted the patients' everyday life problems. All of the tests were significantly predictive of at least some of the behavioral and cognitive deficits reported by patients' carers. However, factor analysis of the patients' dysexecutive symptoms suggested a fractionation of the dysexecutive syndrome, with neuropsychological tests loading differentially on 3 underlying cognitive factors (Inhibition, Intentionality, and Executive Memory), supporting the conclusions that different tests measure different cognitive processes, and that there may be limits to the fractionation of the executive system.

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

Abstract: 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.)

Ecological validity of a simplified version of the multiple errands shopping test

Abstract: Shallice and Burgess (1991) reported the utility of the Multiple Errands Test (MET) in discriminating executive deficits in three frontal lobe patients with preserved high IQ, who were otherwise unimpaired on tests of executive function. The aim of this study was to ascertain the value of a simplified version of the MET (MET‐SV) for use with the range of people more routinely encountered in clinical practice. Main findings were as follows: 1) The test discriminated well between neurological patients and controls, and the group effects remained when the difference in current general cognitive functions (WAIS‐R FSIQ) was taken into account. 2) The best predictors of performance in the healthy control group (n 5 46) were age and the number of times participants asked for help (with more requests associated with poorer performance). 3) In the neurological group, two clear patterns of failure emerged, with performance either characterized by rule breaking or failure to achieve tasks. These two patterns were associated with different dysexecutive symptoms in everyday life. 4) The patients not only made more errors than controls, but also different ones. A scoring method that took this into account markedly increased test sensitivity. 5) Many patients passed traditional tests of executive frontal lobe function but still failed the MET‐SV. This pattern was strongly associated with observed dysexecutive symptoms in everyday life. The results demonstrate the clinical utility of the test, and suggest that there are two common and independent sources of failure on multitasking tests in a general neurological population: memory dysfunction, and initiation problems. (JINS, 2003, 9, 31‐44.)

The Development of an Ecologically Valid Test for Assessing Patients with a Dysexecutive Syndrome

Abstract: (1998). The Development of an Ecologically Valid Test for Assessing Patients with a Dysexecutive Syndrome. Neuropsychological Rehabilitation: Vol. 8, Assessment of Attention and Executive Function. Guest Editor: J. Crawford, pp. 213-228.

Exploring the Central Executive

Abstract: The central executive component of working memory is a poorly specified and very powerful system that could be criticized as little more than a homunculus. A research strategy is outlined that attempts to specify and analyse its component functions and is illustrated with four lines of research. The first concerns the study of the capacity to coordinate performance on two separate tasks. A second involves the capacity to switch retrieval strategies as reflected in random generation. The capacity to attend selectively to one stimulus and inhibit the disrupting effect of others comprises the third line of research, and the fourth involves the capacity to hold and manipulate information in long-term memory, as reflected in measures of working memory span. It is suggested that this multifaceted approach is a fruitful one that leaves open the question of whether it will ultimately prove more appropriate to regard the executive as a unified system with multiple functions, or simply as an agglomeration of indepe...

Executive Function and the Frontal Lobes: A Meta-Analytic Review

Abstract: Currently, there is debate among scholars regarding how to operationalize and measure executive functions. These functions generally are referred to as “supervisory” cognitive processes because they involve higher level organization and execution of complex thoughts and behavior. Although conceptualizations vary regarding what mental processes actually constitute the “executive function” construct, there has been a historical linkage of these “higher-level” processes with the frontal lobes. In fact, many investigators have used the term “frontal functions” synonymously with “executive functions” despite evidence that contradicts this synonymous usage. The current review provides a critical analysis of lesion and neuroimaging studies using three popular executive function measures (Wisconsin Card Sorting Test, Phonemic Verbal Fluency, and Stroop Color Word Interference Test) in order to examine the validity of the executive function construct in terms of its relation to activation and damage to the frontal lobes. Empirical lesion data are examined via meta-analysis procedures along with formula derivatives. Results reveal mixed evidence that does not support a one-to-one relationship between executive functions and frontal lobe activity. The paper concludes with a discussion of the implications of construing the validity of these neuropsychological tests in anatomical, rather than cognitive and behavioral, terms.

Traumatic brain injury.

Abstract: In childhood, traumatic brain injury (TBI) poses the unique challenges of an injury to a developing brain and the dynamic pattern of recovery over time, inflicted TBI and its medicolegal ramifications. The mechanisms of injury vary with age, as do the mechanisms that lead to the primary brain injury. As it is common, and is the leading cause of death and disability in the USA and Canada, prevention is the key, and we may need increased legislation to facilitate this. Despite its prevalence, there is an almost urgent need for research to help guide the optimal management and improve outcomes. Indeed, contrary to common belief, children with severe TBI have a worse outcome and many of the consequences present in teenage years or later. The treatment needs, therefore, to be multifaceted and starts at the scene of the injury and extends into the home and school. In order to do this, the care needs to be multidisciplinary from specialists with a specific interest in TBI and to involve the family, and will often span many decades.