Historically, research that examines cognitive deficits in neurological patient populations has remained separate from research that uses mathematical models to examine """"""""normal cognition. However, these two areas have begun to merge (e.g., Farah, 1990; Maddox, et.al., 1995). Model-based analyses are often superior to traditional specific cognitive deficit, and (c) determine the magnitude of these deficits. Maddox, el. al. (1995) utilized modeling techniques to examine PD patients' ability (a) to integrate information from two aspects of a stimulus (termed dimensional integration, DI), and (b) to attend selectively to one aspect of a stimulus while ignoring the other (termed selective attention; SA). We found that PD patients showed no DI deficits, but a large proportion of PD patients did show SA deficits. This proposal outlines two extensions of this research. Project 1 will examine the differential effects of stimulus separability and integrality on PD patients' SA performance. Normal subjects' SA performance is strongly influenced by stimulus separability and integrality; SA is easy with separable dimension, but is hard with integral dimensions (Maddox, 1992). Maddox et al. (1995) utilized integral dimensions and found SA deficits in PD patients. In Project 1, subjects will participate in two experiments; one that uses integral dimensions, and the other that uses separable dimensions. Model-based analyses will be applied to isolate and quantify the effects of stimulus integrality on PD patients' SA performance. Project 2 will examine the differential effects of an internal vs. external criterion on PD patients' DI performance. Maddox et al. (1995) found that PD patient were not impaired in their DI ability when no internal referent was required. Some have argued that PD patients had more impaired on tasks that place greater demands on the internal control of attention (e.g., Brown & Marsden, 1988). Subjects will participate in two experiments like those used in Project 1, however one will require an external criterion, and the other will not model-based analyses will again be used to isolate and quantify the effects of an internal vs. external criterion on PD patients' DI performance.
| Filoteo, J V; Maddox, W T; Davis, J D (2001) Quantitative modeling of category learning in amnesic patients. J Int Neuropsychol Soc 7:1-19 |
| Maddox, W T; Filoteo, J V (2001) Striatal contributions to category learning: quantitative modeling of simple linear and complex nonlinear rule learning in patients with Parkinson's disease. J Int Neuropsychol Soc 7:710-27 |
| Filoteo, J V; Maddox, W T (1999) Quantitative modeling of visual attention processes in patients with Parkinson's disease: effects of stimulus integrality on selective attention and dimensional integration. Neuropsychology 13:206-22 |
| Maddox, W T; Filoteo, J V; Huntington, J R (1998) Effects of stimulus integrality on visual attention in older and younger adults: a quantitative model-based analysis. Psychol Aging 13:472-85 |
