Identifying simulators of cognitive deficit through combined use of neuropsychological test performance and event-related potentials.

Event-related potential (ERP) methods for identifying malingering of cognitive deficit assume that elements of brain/cognitive functioning are not under a person's direct control, whereas neuropsychological methods assume that malingered cognitive deficit will present differently than true impairment in terms of level or pattern of errors on tests of cognitive function. Two studies were conducted to examine the combined use of neuropsychological and ERP methods for identifying malingering because of the potential independence of these approaches. All normal control participants performing at their best level (n = 25) were correctly classified by both ERP and neuropsychological methods. All participants simulating cognitive deficit (n = 35) were correctly classified on the basis of a positive outcome on either the neuropsychological or the ERP method. Results suggest that the neuropsychological and psychophysiological measures of malingering that were studied contribute non-redundant information in the classification of simulators.