82 Single Errors on Trial 1 of the Test of Memory Malingering may be Indicative of Invalid Performance on Neuropsychological Measures in a Sample of Youth Athletes

Abstract

Objective:

The Test of Memory Malingering (TOMM) is a performance validity test (PVT) that aims to assess whether participants are giving adequate effort to perform well on tasks of memory performance (Tombaugh, 1996). Other PVTs, specifically the Forced Choice Recognition Trial in the California Verbal Learning Test, have shown that even single errors may indicate invalid performance (Erdodi et al., 2018). Finally, youth are often understudied in the PVT literature, and athletes are at increased risk of invalid performance on baseline testing due to many wanting to return to play following concussion (Erdal, 2012). Therefore, the objective of the current study is to examine whether single errors on TOMM Trial 1 are indicative of lower, and possibly invalid, cognitive performance in a youth sample, given that cognitive performance declines with even small decreases in effort (Green, 2007).

Participants and Methods:

Healthy youth athletes (n=174) aged 8-16 years (M=12.07) completed the TOMM as well as other neuropsychological measures during baseline neuropsychological evaluation in a clinical research program for sports concussion. Independent samples t-tests compared youth athletes who scored 49 points on the TOMM (n=28) to youth athletes who scored a perfect 50 (n=50) across several groupings of neuropsychological measures. Participants who scored less than 49 or who didn’t complete the TOMM were excluded from the analyses.

Results:

Participants scoring 50/50 on TOMM Trial 1 scored significantly higher on Stroop Color Naming task (p=0.036), Verbal Learning Delayed task from the second edition of the Wide Range Assessment of Learning and Memory (WRAML-2, p=0.018), and Letter Number Sequencing task from the Weschler Intelligence Scale for Children (WISC-IV, p=0.025), relative to participants scoring 49/50. Though not statistically significant, results also showed a trend toward participants scoring 50/50 scoring higher on nearly every test in the battery.

Conclusions:

Participants with a single error on TOMM Trial 1, as compared to participants with a perfect score, performed significantly worse on a processing speed task, a verbal learning task, and a working memory task as part of a comprehensive neuropsychological battery. The single-error group also trended toward scoring lower on nearly all of the remaining attention, processing speed, perceptual ability, memory, and executive functioning tasks in the battery. The results could lead to a more liberal interpretation of TOMM scores, given that the trend towards lower performance may be due to putting forth significantly less effort. These results point to the need for a similar comparison of the TOMM in a larger sample size, as greater power may reveal even more significant differences in performance. Findings also emphasize the importance of viewing performance validity on a continuum rather than as a dichotomous pass/fail. Understanding the TOMM and how single errors may be indicative of poorer performance in a youth sample could help to reframe the way PVT results are interpreted in clinical and forensic settings.