Finger Tapping Test performance as a measure of performance validity.

The Finger Tapping Test (FTT) has been presented as an embedded measure of performance validity in most standard neuropsychological evaluations. The present study evaluated the utility of three different scoring systems intended to detect invalid performance based on FTT. The scoring systems were evaluated in neuropsychology cases from clinical and independent practices, in which credible performance was determined based on passing all performance validity measures or failing two or more validity indices. Each FTT scoring method presented with specificity rates at approximately 90% and sensitivity of slightly more than 40%. When suboptimal performance was based on the failure of any of the three scoring methods, specificity was unchanged and sensitivity improved to 50%. The results are discussed in terms of the utility of combining multiple scoring measures for the same test as well as benefits of embedded measures administered over the duration of the evaluation.