Activity in default mode network discriminates between personally familiar and experimentally familiar faces in older adults

Poster Session B - Sunday, April 14, 2024, 8:00 – 10:00 am EDT, Sheraton Hall ABC

Stefani Morgan¹ (sm22be@fsu.edu), Sophie Allen², Emma Tripp², Chris Martin^1,2; ¹Florida State University, Program in Neuroscience, ²Florida State University, Department of Psychology

The ability to recognize a personally familiar face, such as a loved one, is a cognitive function used in everyday life. However, adults diagnosed with Alzheimer’s disease (AD) experience an impairment of this ability, which contributes to the negative impact AD has on quality of life. Here, we used functional magnetic resonance imaging (fMRI) to characterize differences in neural activity related to face recognition in older adults with and without indications of mild cognitive impairment (MCI), a clinical precursor to AD. Specifically, we examined differences in brain activity evoked by recognition of personally familiar (PF) faces, experimentally familiar (EF) faces of strangers, and novel faces of strangers. Participants used a digital camera to capture standardized images of people they deemed personally familiar. EF faces were learned in a series of lab-based encoding tasks. Participants were asked to discriminate between the three categories of faces (PF, EF, and novel) during functional neuroimaging. We hypothesized discernible differences in neural activity for the different face categories. Our results revealed a differentiation for PF and EF faces in the default mode network (DMN). Specifically, medial parietal cortex, medial prefrontal cortex, and lateral temporal cortex were significantly more active for PF than either EF or novel faces. No significant differences were observed between EF and novel faces at the level of whole-brain univariate activation profiles. These results align with the role of the DMN in self-referential processing and the cognitive processes involved in person identity recognition.

Topic Area: EMOTION & SOCIAL: Person perception