Eye Movement Effects in Simulated Object Recognition Memory Impairment

Abstract

Malingering is the purposeful fabrication of symptoms for secondary gain. Memory problems are the most reported symptom, and object recognition tests are often used in clinical settings to evaluate these claims. Past research has shown that eye movements can indirectly index memory, in that greater viewing is directed at studied stimuli 500-750 ms after display onset. The present study evaluated eye movements as a potential method of detecting feigned memory impairment. Forty-eight participants, half simulators, studied standardized images and took a memory test. Several levels of analysis were used to detect broad trends and brief effects. Simulators performed significantly worse on the behavioral task, but also directed less viewing time towards studied stimuli overall and during the first 3s when providing correct responses. On Miss trials, they viewed studied stimuli even less in the last 3s. Although simulators demonstrated the early viewing effect, it occurred slightly later (750-1000 ms). The 250 ms data provided more useful information, as did Hit-Miss difference scores. A behavioral measure (corrected recognition score) emerged as the single best indicator of malingering. However, eyetracking methodology was able to provide five eye movement variables that demonstrated good psychometric properties and provided incremental diagnostic utility allowing for all cases to be correctly classified. Therefore, a multimethod approach proved to be most effective in detecting simulated memory impairment in this sample.