Biomedical subjects

Nick Alderman

Publications and source records attributed to Nick Alderman.

5 recordsLinked to original sources

PubMed2006

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

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.

Cognition Disorders↗

PubMed2004

Measuring the relationship between overt aggression and expectations: a methodology for determining clinical outcomes.

The presence of aggressive behaviour following traumatic brain injury imposes special challenges within rehabilitation centres. Survivors of traumatic brain injury constitute a heterogeneous population amongst whom problems with increased irritability and aggression are characteristic. There is a clear need to determine what treatment approaches might be helpful in reducing aggressive behaviour. Whilst single-case experimental methodologies including reversal and multiple baseline designs seem ideal for this purpose, the compelling need to minimize risk can compromise their deployment, especially when aggression takes the form of physical assaults on others. When this is the case, there are difficulties in assessing whether a change in aggressive behaviour represents a successful response to treatment or is simply a function of reduced demand in the environment. The contributions made to understanding the relationship between aggression and expectations made on patients participating within rehabilitation will be explored here. A possible means of quantifying demands using the Neurobehavioural Expectations Scale will be described. Three case studies are presented that suggest that a methodology that employs concurrent use of this tool with the Overt Aggression Scale -- Modified for Neurorehabilitation, can enable objective evaluation to be made of the effects of rehabilitation on behaviour, without increasing risk.

Activities of Daily Living↗

PubMed2003

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

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 = 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.

Adult↗

PubMed2002

Is accurate self-monitoring necessary for people with acquired neurological problems to benefit from the use of differential reinforcement methods?

Challenging behaviour exhibited by people with acquired neurological problems must be managed if their maximum rehabilitation potential is to be achieved. Differential reinforcement of low rates of responding (DRL) appears to be an effective method for this. The effectiveness of DRL in the presence of severe cognitive deficits, including disorders of attention and memory, is nevertheless surprising. Indeed, such difficulties may prevent individuals with brain injury benefiting from operant conditioning procedures because of impairment of the central executive component of working memory. Consequently, use of other behavioural techniques such as response cost and self-monitoring training (SMT) have been adopted, as it has been argued they circumvent neuropsychological constraints to learning by directing attention to aspects of behaviour not being monitored. DRL, however, may be more desirable as it involves minimal intrusion; is concerned with establishment of pro-social behaviour; and treatment gains can occur rapidly and be maintained for long periods following withdrawal. Whether DRL is dependent upon accurate self-monitoring is addressed through the study of three people participating in rehabilitation. This shows DRL can be effective, despite severe cognitive impairments, but SMT facilitates greater improvements in selective attention. How DRL may circumvent cognitive impairment is discussed.

Adult↗

PubMed2002

Aggressive behaviour observed within a neurobehavioural rehabilitation service: utility of the OAS-MNR in clinical audit and applied research.

The Overt Aggression Scale-Modified for Neurorehabilitation (OAS-MNR) has been proposed as a means of standardizing descriptions of post-acute aggressive behaviour disorders amongst people with acquired brain injury. Single cases in the literature have illustrated its clinical utility. In this paper, its contribution to clinical audit and applied research is explored. The scale was used to record all aggressive behaviour exhibited by 46 patients participating in a neurobehavioural programme during a 14 day period. Data for 3914 acts of aggression were captured. Whilst most was verbal, 443 comprised physical assaults on others. Results suggest the OAS-MNR can be usefully employed to audit practice, and has a role to play in resource allocation: however, efficacy remains best judged at the single case level. Regarding clinical research, it was found that patients with low language function were more likely to physically assault others in the absence of identifiable antecedents. Furthermore, this was more severe and required more intrusive interventions to manage it than aggression shown by the same patients which had identifiable antecedents, or any aggression exhibited by patients whose language was better preserved. It is argued that poor language function creates significant barriers to the treatment of aggression, and, whilst intervention methods with good outcome have previously been described, these are no longer routinely available in the UK. An appeal to reverse this is made.

Adolescent↗