Chronic Pain: Utility of an Eye-Tracker Integrated Stand-alone Performance Validity Test

Abstract

Noncredible cognitive performance among chronic pain patients garners increased clinical attention. The Word Memory Test (WMT)—a well-established stand-alone validity indicator—was recently integrated with an eye tracker, and its utility was assessed using healthy simulators. The current study expands on this earlier work by assessing the utility of the eye-tracker integrated WMT to detect noncredible cognitive performance in the context of chronic pain. Chronic pain outpatients were randomly assigned to either a simulation (i.e., patients simulating cognitive impairment; n = 22) or honest control (i.e., patients performing to the best of their ability; n = 23) conditions. They then completed the WMT’s immediate recognition (IR) subtest while their eye movements were recorded. Simulators gazed less at relevant stimuli and gazed more at irrelevant stimuli than controls. Sensitivity levels tended to be low to moderate when maintaining specificities ≥ 90%, as customary in the field. While a previously developed scale that integrates eye movement measures using a logistic regression did not adequately differentiate the groups, conjunctive rules (i.e., the participant was required to fail both the WMT's classification scheme and the eye movement measure with the strongest discriminative capacity) were associated with higher specificities than those of the WMT’s conventional classification scheme. Overall, the eye-tracker integrated WMT shows initial clinical utility for detecting noncredible cognitive performance. Decreasing costs of eye trackers and enhanced usability will hopefully encourage further research of their utility for detecting noncredible cognitive performance and integration of this novel technology with other stand-alone validity indicators.