Unilateral spatial neglect is one of the most striking consequences of right-sided brain damage and is characterised by the patient's failure to respond to stimuli on the side contralateral to the cerebral lesion. Visual neglect disrupts many aspects of daily living such as mobility, dressing and reading, yet the underlying mechanisms remain poorly understood. Previous attempts to explain the condition have resulted in a wide variety of terms and test procedures. An adequate theoretical account of neglect requires a data-base that represents the basic patterns of impaired and preserved performance within and between individuals. Despite considerable interest in neglect, no such large scale data-base currently exists. A consideration of the factors and difficulties that contribute to this situation are reviewed in Chapter 2. The present thesis describes the development, standardisation and validation of a test battery designed to identify a wide variety of neglect behaviours observed in clinical practice. The Behavioural Inattention Test (BIT) which was standardised using a large stroke population (80) is described. Unlike existing studies of visual neglect the BIT relates test results to functional assessment and the rehabilitation of the patient. Using the test battery and normative data from 50 age matched controls, 30 patients were classified as demonstrating neglect. Neglect is more frequent and severe following right rather than left sided lesions. Inter-rater, test-retest, and parallel forms of the test show the neglect battery to be a reliable measure of patient performance. Evidence from factor analysis and correlations with "conventional" and clinical judgments demonstrate the underlying validity of the battery. Detailed group and single case studies are used to show how results from the test battery contribute and redefine current conceptions of visual neglect. These studies address aspects of visual neglect, such as the effects of line length and hemispatial position in the case of line bisection performance. They also consider vertical dimensions of visual neglect and present evidence to suggest that what is "neglected in visual neglect may still influence patient's judgments and behaviour". It is concluded that recent developments within clinical assessment and cognitive neuropsychology provide a conceptual framework within which to investigate and characterise the condition in a manner that underpins rehabilitation programmes.
Permanent link to this resource: https://doi.org/10.24384/x49w-tb23
Halligan, Peter W.
Supervisors: Lindsay, Roger
Faculty of Health and Life Sciences
Year: 1989
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