Year of Award


Document Type

Thesis - Campus Access Only

Degree Type

Doctor of Philosophy (PhD)

Degree Name

Clinical Psychology

Department or School/College

Department of Psychology

Committee Chair

Stuart Hall

Commitee Members

Duncan Campbell, Daniel Denis, Dan Doyle, Paul Silverman


brain injury simulation, personality assessment


University of Montana


This study provided a comparison of performance characteristics between honest responders and brain injury simulators on the Personality Assessment Inventory (PAI) and Minnesota Multiphasic Personality Inventory (MMPI-2). Honest responders (n=50) were instructed to respond accurately while Brain Injury Simulators {n = 50) were instructed to fake cognitive impairment. Using a cut-off score of > 7, overall the Gass Neurocorrection scale outperformed all scales at detecting honest responders and brain injury simulators with sensitivity and specificity ratings of .66 and .92, respectively. The Gass also demonstrated the greatest positive predictive value with an area under the curve of .87. The performances of the NIM (cutoff = >73) and FBS (cutoff = >28) followed that of the Gass. The overall sensitivity/specificity ratings for the NIM, .48 and 1.0, respectively, outperformed those of the FBS, .38 and 1.0 respectively. An opposite trend for the measures was observed when assessed for positive predictive value with area under the ROC favoring the FBS (.850) over the NIM (.848). The sensitivity/specificity ratings were poor for both the MAL (cutoff = > 3; .26, 1.0) and RDF (cutoff = >0; .50, .84). The MAL and RDF also yielded to lowest area under the ROC with rates of .724 and .680, respectively. These findings suggest that among the five measures, the Gass cutoff may have the most utility in the medico-legal context, with both the NIM and FBS second to the Gass, demonstrating clinical utility as well.

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© Copyright 2009 Cameron Craig Brewer