Visual processing of emotional faces is preserved in mild cognitive impairment

Background: Research suggests that deficits in emotion recognition are evident in individuals with amnestic mild cognitive impairment (aMCI), a group 'at risk' of developing dementia. The mechanisms underlying this deficit, however, are unclear. Objective: In this study, we sought to determine whether there are alterations in the way in which individuals with MCI visually explore emotional facial stimuli. Methods: Eighteen healthy older controls (mean age = 64.6 years) and 32 individuals with MCI were recruited including 18 with the non-amnestic multiple domain (naMCI-md) subtype (mean age = 63.8 years) and 14 with the amnestic multiple domain (aMCI-md) subtype (mean age = 67.9 years). All participants were given a novel eye-tracking paradigm to investigate eye gaze while viewing images of emotional faces on a computer screen. Results: Analyses of eye gaze revealed no significant difference in the percentage of time that groups spent fixating on facial and peripheral facial regions when viewing emotional faces. All participants showed a relative preference for the eye region of faces relative to all other regions. Individuals with aMCI-md were found to be less accurate than controls and naMCI-md on emotion recognition measures. For naMCI-md individuals, significant relationships were found between efficiencies in visual scanning and increased fixation time on the eye region. Conclusions: Visual processing strategies adopted by aMCI-md individuals when exploring emotional faces do not significantly differ from those of healthy controls or naMCI-md individuals. This suggests that impaired facial emotion recognition in aMCI-md is not likely accounted for by visual processing differences, but rather may reflect an eroded ability to extract meaningful cues from the eye region.