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ORIGINAL RESEARCH article

Front. Neurosci.

Sec. Neurodegeneration

This article is part of the Research TopicBiomarkers for the identification of effective treatments for neurodegenerative diseaseView all 7 articles

Cerebral responses to Famous face recognition as a potential functional biomarker of mild cognitive impairment

Provisionally accepted
  • 1Department of Neuropsychiatry, Nippon Medical School Tama-Nagayama Hospital, Tama, Japan
  • 2Graduate School of Medicine, Department of Neuropsychiatry, Nihon Ika Daigaku, Bunkyo, Japan
  • 3Graduate School of Medicine, Department of Pharmacology, Nihon Ika Daigaku, Bunkyo, Japan

The final, formatted version of the article will be published soon.

Abstract Background: Social cognition impairments—including difficulties in recognizing personally familiar faces—occur early in mild cognitive impairment (MCI) and can lead to social withdrawal, reduced motivation, and secondary depression. Face recognition is central to social cognition, yet its neural basis in MCI remains insufficiently understood. This study examined whether task-based fMRI during famous face recognition could capture early alterations in the parahippocampal gyrus (PHG) and posterior cingulate cortex (PCC), key nodes supporting semantic access and internally directed cognition within the default mode network (DMN). Methods: Thirty-two participants (20 healthy controls, 12 MCI) completed two fMRI tasks: famous vs. nonfamous face judgment and face vs. object categorization. A 2×2 factorial analysis assessed Group and Task effects, and small-volume correction was applied to PHG and PCC. Results: Behavioral accuracy was comparable between groups; however, whole-brain analyses revealed markedly reduced activation in the left PHG and PCC in the MCI group during socially meaningful face processing. ROI analyses further demonstrated that the left PHG reduction remained significant after FWE correction, whereas PCC showed a weaker reduction that did not survive correction for multiple comparisons. Conclusion: These findings suggest early alterations in PHG–PCC networks that precede observable behavioral decline in MCI. In particular, reduced activation in the left PHG may reflect early disruptions in semantic access and internally directed processing. Assessing these socially relevant neural circuits alongside established amyloid and tau biomarkers may provide complementary functional insight into early cognitive vulnerability in individuals at risk for dementia.

Keywords: biomarker, Famous faces, fMRI, Mild Cognitive Impairment, Parahippocampal Gyrus

Received: 03 Sep 2025; Accepted: 15 Dec 2025.

Copyright: © 2025 Koeda, Ikeda, Okubo and Tateno. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Michihiko Koeda

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