This proposal is based on the premise that complex cognitive disorders in brain-damaged subjects can be analyzed in an objective, quantitative manner. Such precision is necessary to get beyond qualitative descriptions and to probe for underlying mechanisms. In the syndrome of unilateral spatial neglect, patients fail to orient towards, respond to, or act on stimuli in space contralateral to their lesion. Neglect may reflect a disorder in the ability to direct attention into contralateral space. During his fellowship, the Candidate discovered that abnormal behavior of patients with neglect may be precisely captured by the simple mathematical formula, psi = K(phi)beta. This power function relates the quantity of stimuli of which these patients are aware (psi) to the quantity of stimuli presented to them (phi). The constant (K) and the exponent (beta) are empirically derived. The observation is of particular significance because the psychological experience of sensations in normal subjects is also related to objective measures of sensory magnitude by power functions. Power function analyses uncover specific quantitative ways in which neglect behavior is similar to and deviates from normal. The present investigation will extend preliminary observations by testing left and right brain damaged patients and normal subjects on line bisection, cancellation and reading tasks. Power function analyses will be applied to these tasks to examine 1) the relationship between the function and the anatomy of attentional networks, 2) develop a methodology to investigate patterns of recovery after acute brain damage, 3) assess disturbances of attentional capacity after damage to attentional networks, and 4) clarify the consequences of such damage to mental representations. It is anticipated that the Specific Aims proposed will establish power function analyses as a novel and precise method to investigate mechanisms underlying the syndrome of unilateral spatial neglect.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Clinical Investigator Award (CIA) (K08)
Project #
5K08NS001702-05
Application #
2609525
Study Section
NST-2 Subcommittee (NST)
Program Officer
Jacobs, Tom P
Project Start
1993-12-10
Project End
1999-11-30
Budget Start
1997-12-01
Budget End
1999-11-30
Support Year
5
Fiscal Year
1998
Total Cost
Indirect Cost
Name
University of Alabama Birmingham
Department
Neurology
Type
Schools of Medicine
DUNS #
004514360
City
Birmingham
State
AL
Country
United States
Zip Code
35294
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Chatterjee, A (1998) Motor minds and mental models in neglect. Brain Cogn 37:339-49
Chatterjee, A; Thompson, K A (1998) Weigh(t)ing for awareness. Brain Cogn 37:477-90
Chatterjee, A; Southwood, M H (1995) Cortical blindness and visual imagery. Neurology 45:2189-95
Chatterjee, A (1995) Cross-over, completion and confabulation in unilateral spatial neglect. Brain 118 ( Pt 2):455-65
Chatterjee, A (1994) Picturing unilateral spatial neglect: viewer versus object centred reference frames. J Neurol Neurosurg Psychiatry 57:1236-40