Neuroanatomical correlates of malingered memory impairment: Event-related fMRI of deception on a recognition memory task

Abstract

Primary objective: Event-related, functional magnetic resonance imaging (fMRI) data were acquired in healthy participants during purposefully malingered and normal recognition memory performances to evaluate the neural substrates of feigned memory impairment.Methods and procedures: Pairwise, between-condition contrasts of neural activity associated with discrete recognition memory responses were conducted to isolate dissociable neural activity between normal and malingered responding while simultaneously controlling for shared stimulus familiarity and novelty effects. Response timing characteristics were also examined for any association with observed between-condition activity differences.Outcomes and results: Malingered recognition memory errors, regardless of type, were associated with inferior parietal and superior temporal activity relative to normal performance, while feigned recognition target misses produced additional dorsomedial frontal activation and feigned foil false alarms activated bilateral ventrolateral frontal regions. Malingered response times were associated with activity in the dorsomedial frontal, temporal and inferior parietal regions. Normal memory responses were associated with greater inferior occipitotemporal and dorsomedial parietal activity, suggesting greater reliance upon visual/attentional networks for proper task performance.Conclusions: The neural substrates subserving feigned recognition memory deficits are influenced by response demand and error type, producing differential activation of cortical regions important to complex visual processing, executive control, response planning and working memory processes.