Dedifferentiated face processing in older adults is linked to lower resting state metabolic activity in fusiform face area

• We used multimodal brain imaging to examine possible mediators of age-related neural dedifferentiation (less specific neural activation) to different categories of stimuli that had been shown in previous research. Specifically, we examined resting blood flow and brain activation in areas involved in object, place and face perception. We observed lower activation, specificity, and resting blood flow for older adults (OA) than younger adults (YA) in the fusiform face area (FFA) but not in the other regions of interest. Mediation analyses further revealed that FFA resting state blood flow mediated age differences in FFA specificity, whereas age differences in visual and cognitive function and cortical thickness did not. Whole brain analyses also revealed more activated voxels for all categories in, OA, as well as more frontal activation for faces but not for the other categories in OA than YA. Less FFA specificity coupled with more frontal activation when passively viewing faces suggest that OA have more difficulty recruiting specialized face processing mechanisms, and the lower FFA metabolic activity even when faces are not being processed suggests an OA deficiency in the neural substrate underlying face processing. Our data point to a detuning of face-selective mechanisms in older adults.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Neurologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Neurology (hsv//eng)

Nyckelord

Aging

Face processing

Dedifferentiation

FMRI

Fusiform face area

Cerebral blood flow

age-related-changes

selective cortical regions

large-scale

facial

identity

visual-cortex

angry faces

recognition

activation

fmri

system

Neurosciences & Neurology

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