Evaluation of Various Detection Strategies in the Assessment of Noncredible Memory Performance: Results of Two Experimental Studies

Objective: This article investigates the accuracy of individual and combined indicators based on different strategies for detecting noncredible performance as part of a new test for the continuous assessment of short-term memory. Method: In two independent studies, we assessed three groups of simulators, cognitively impaired patients, and nonimpaired community members with four tasks separated by a distractor. Results: Pairwise comparisons between receiver operating characteristic (ROC) curves revealed significant differences between two clusters of indicators: mean recognition, inconsistent responses in recognition, and false positives (area under the ROC curves > .800) proved more accurate than delayed recall and false negatives (area under the ROC curves < .800) in discriminating simulators from patients. Likewise, both studies revealed that adding the false positives indicator based on cued recall to mean recognition incrementally improved classification accuracy (including sensitivity, positive predictive value, and negative predictive value ) compared with the recognition indicator alone. Conclusions: Our results support the association of two distinct indicators for the assessment of noncredible performance, of which one should be a forced-choice indicator.