Neural correlates of impaired learning and recognition of novel faces in mild cognitive impairment

Face memory impairment significantly affects social interactions and daily functioning in individuals with mild cognitive impairment (MCI). While deficits in recognizing familiar faces among individuals with MCI have been reported, their ability to learn and recognize unfamiliar faces remains unclear. This study examined the behavioral performance and event-related potentials (ERPs) of unfamiliar face memorization and recognition in MCI. Fifteen individuals with MCI and 15 healthy controls learned and recognized 90 unfamiliar neutral faces. Their performance accuracy and cortical ERPs were compared between the two groups across the learning and recognition phases. Individuals with MCI had lower accuracy in identifying newly learned faces than healthy controls. Moreover, individuals with MCI had reduced occipitotemporal N170 and central vertex positive potential responses during both the learning and recognition phases, suggesting impaired initial face processing and attentional resources allocation. Also, individuals with MCI had reduced central N200 and frontal P300 responses during the recognition phase, suggesting impaired later-stage face recognition and attention engagement. These findings provide neurobehavioral evidence for impaired learning and recognition of unfamiliar faces in individuals with MCI. Individuals with MCI may have face memory deficits in both early-stage face processing and later-stage recognition in MCI.