Detecting feigned traumatic brain injury with eye tracking during a test of performance validity

Eye-tracking is a promising technology to enhance assessment of performance validity. Research has established that ocular behaviors are reliable biomarkers of (un)conscious cognitive processes, and they have distinguished deceptive from honest responding in experimental paradigms. This study examined the incremental utility of eye-tracking on a clinical performance validity test (PVT) in distinguishing adults with verified TBI from adults coached to feign cognitive impairment.

Participants were 49 adults with moderate-to-severe TBI (TBI), 47 healthy adults coached to simulate TBI (SIM), and 67 healthy comparisons providing full effort (HC). A PVT linked to eye-tracking was completed in the context of a full neuropsychological battery.

Kruskal-Wallis tests revealed that eye-tracking indices did not differ among the groups during presentation of stimulus items but did differ during forced-choice trials. Compared to TBI and HC, SIM had significantly more transitions, fixations, and time spent looking at correct and incorrect response options. Logistic regressions and ROC curve analyses showed that accuracy was the best predictor of SIM versus HC. For SIM versus TBI, eye-tracking indices exceeded accuracy in distinguishing the groups. Eye-tracking added incremental predictive value to accuracy for both SIM-HC and SIM-TBI discriminations.

Eye-tracking indicated that persons feigning TBI showed multiple signs of greater cognitive effort than persons with verified TBI and healthy comparisons. In the comparison of greatest interest (SIM vs. TBI) eye-tracking best predicted group status and yielded excellent discrimination when combined with accuracy. Eye-tracking may be an important complement to traditional accuracy scores on PVTs. (PsycINFO Database Record (c) 2020 APA, all rights reserved).