Portland digit recognition test-computerized: Measuring response latency improves the detection of malingering

Abstract

This study assessed the use of response latency as an aid in the detection of malingering using a computerized version of the Portland Digit Recognition Test (PDRT-C). Two groups of 30 college student malingerers (one coached and one uncoached), 30 head-injury patients (CHI), and 30 age-and education-matched controls were administered the PDRT-C. A discriminant function using the total correct and response latency data successfully classified 74% of the malingerers and 100% of the CHI and normal control subjects on validation. Coached malingerers were more successful at avoiding detection than uncoached malingerers. However, the detection of coached malingerers rose from 47% to 70% by measuring response latency. Overall, 32% fewer errors were made using the total correct and response latency data when compared to classification rates using the total correct score alone.