高齢期における意思決定は，仕事の継続判断，治療選択，老後のリスク管理や生活設計など，生活に大きく影響します。一方で，加齢に伴う認知機能の低下により，複雑な選択肢や確率判断を要する選択，迅速な判断，新規な意思決定が困難になります。しかしながら，膨大な情報からリアルタイムで複数の選択を生み出すことが可能な大規模言語モデルは，高齢者の意思決定を大きく変える可能性があります。私たちの研究室では，加齢が意思決定に及ぼす影響やAIの使用が高齢者の意思決定に及ぼす影響について研究を行っています。

Decision making in later life has profound implications for everyday living, including decisions about continuing employment, selecting medical treatments, managing risks in old age, and planning one’s future life course. However, age-related declines in cognitive functioning can make it increasingly challenging to manage decisions that involve complex option structures, probabilistic reasoning, time pressure, or novelty. In this context, large language models—which can generate multiple decision options in real time based on vast amounts of information—have the potential to fundamentally transform decision making among older adults. In our laboratory, we examine how aging shapes decision-making processes and investigate the extent to which AI use influences decision making in older adulthood.

Ishibashi, S., Tamura, K., Goma, A., Yamamoto, K., & Masumoto, K. (2025). Generative AI compensates for age-related cognitive decline in decision making: Preference-aligned recommendations reduce choice difficulty. arXiv preprint arXiv:2511.21164.

Masumoto, K., Tian, M., & Yamamoto, K. (2022). Age differences in option choice: Is the option framing effect observed among older adults?. Frontiers in Psychology, 13, 998577.

Masumoto, K., Shiozaki, M., & Taishi, N. (2020). The impact of age on goal-framing for health messages: The mediating effect of interest in health and emotion regulation. PLoS One, 15(9), e0238989.

塩﨑麻里子・佐藤望・増本康平 (2020). 認知症高齢者の家族介護者が代理意思決定場面で経験した後悔に関する質的調査研究. 老年社会科学, 42(3), 200-208.（Shiozaki, M., Sato, N., & Masumoto, K., Exploratory study of regret experienced by family caregivers of dementia patients in surrogate decision-making. Japanese Journal of Gerontology, , 42(3), 200-208）

記憶は出来事や経験をそのまま記録する装置ではありません。私たちの記憶の多くは忘却され，保持された記憶も変容します。記憶が記録ではないとしたら私たちの記憶にはどのような役割があるのでしょうか。私たちの記憶は，将来の行動選択（指示機能），人との情報共有によるコミュニケーションの促進（社会機能），嫌な記憶の忘却や良い記憶の想起による感情のコントロール（感情調整機能），絶えず変化する自分自身の感覚や価値の統合（自己機能）を担っています。高齢になって振り返る人生は全て記憶です。私たちの研究室では，このような記憶の機能が加齢とともにどのように変化するのかについて研究を行っています。

Memory is not a device that records events and experiences verbatim. Much of what we experience is forgotten, and even retained memories are subject to transformation over time. If memory is not merely a record, what roles does it play? Human memory supports future behavioral choices (directive function), facilitates communication through the sharing of information with others (social function), regulates emotions by attenuating unpleasant memories and selectively recalling positive ones (emotion regulation function), and integrates one’s continually evolving sense of self and values (self function). In later life, the act of reflecting on one’s life is entirely constituted by memory. In our laboratory, we investigate how these functional roles of memory change with aging.

Masumoto, K., Harada, K., Yamamoto, K., Sato, K., & Shiozaki, M. (2025). Why do older adults repeatedly recall the past events? Associations with autobiographical memory functions and cognitive function. PsyarXiv https://doi.org/10.31234/osf.io/mvsy7_v1

Masumoto, K., Sato, K., Harada, K., Yamamoto, K., & Shiozaki, M. (2022). Emotional valence of self-defining memories in older adults: A longitudinal study. Consciousness and Cognition, 106, 103431.

増本康平 (2018). 老いと記憶 ~加齢で得るもの、失うもの. 中央公論新社

Masumoto, K. et al. (2015). The role of movement representation in episodic memory of actions: A study in patients with apraxia. Journal of Clinical and Experimental Neuropsychology, 29,1-12.

親や友人の死といった人間関係の喪失，子どもの自立や引退による社会的役割の喪失，病気による健康の喪失など高齢期は他の世代と比較してストレスが多い時期だと言われています。しかしながら，他の世代と比較して不幸ではなく，むしろ幸福感が高いことが報告されています。私たちの研究室では，高齢期のウェルビーイングに何が重要なのか，感情のコントロールは加齢に伴いどのように変化するのかについて研究を行っています。

Later life is often characterized as a period of heightened stress compared with other life stages, owing to multiple forms of loss, including the loss of close relationships through the death of parents or friends, the loss of social roles associated with children’s independence or retirement, and the loss of health due to illness. Nevertheless, empirical evidence indicates that older adults are not less happy than younger generations; rather, they often report equal or even higher levels of well-being. In our laboratory, we examine the psychological factors that are critical for well-being in later life and investigate how emotion regulation changes with aging.

Oriyama, K., Mukai, K., Harada, K., & Masumoto, K. (2024). Relationship between habitual use and degree of emotion regulation: Age differences in cognitive reappraisal and expressive suppression. Experimental Aging Research, 51, 59-72.

Masumoto, K., Harada, K., & Shiozaki, M. (2020). Effect of emotion regulation on mental health of couples in long‐term marriages: One‐Year Follow‐up Study. Japanese Psychological Research, 64(3), 360-368.

Masumoto, K., Taishi, N., & Shiozaki, M. (2016). Age and gender differences in relationships among emotion regulation, mood, and mental Health. Gerontology & Geriatric Medicine, 2, 2333721416637022. 

これまで多くの観察研究が，ウェルビーイングの実現において，社会的つながりが重要であることを一貫して報告しています。しかしながら，社会的つながりを形成することでウェルビーイングを実現する介入研究はほとんどありません。私たちの研究室は，他の研究室と共同で地域コミュニティの社会的つながりを形成し，ウェルビーイングの実現を目指すアクティブエイジングプロジェクトを展開しています。また，大規模な社会的つながりを定量的に評価可能な社会的つながりの評価手法の開発を行っています。

A large number of observational studies have consistently reported that social connectedness is crucial for the realization of well-being. However, there is a notable scarcity of intervention studies that aim to enhance well-being by actively fostering social connections. In response to this gap, our laboratory, in collaboration with other research groups, is conducting an active aging project designed to build social connections within local communities and promote well-being. In addition, we are developing methods that enable the quantitative assessment of large-scale social connectedness.

増本康平, 原田和弘, 谷口隆晴, 打田篤彦, & 近藤徳彦. (2025). 社会的つながりへの介入による超高齢社会の ウェルビーイングの実現―介入の理論・方法・評価―. 心理学評論, 68(2), 149-166.（Masumoto, K., Harada, K., Yaguchi, T., Uchida, A., & Kondo, N., (2025) Achieving Well-being in a Super-aging Society Through Interventions for Social Connectedness: Theory, Methods, and Evaluation of Interventions. Japanese Psychological Review, 68(2), 149-166.）

Harada, K., Masumoto, K., Katagiri, K., Fukuzawa, A., Touyama, M., Sonoda, D., Chogahara, M., Kondo, N. & Okada, S. (2021). Three-year effects of neighborhood social network intervention on mental and physical health of older adults. Aging & Mental Health, 25, 2235-2245.

Harada, K., Masumoto, K., Katagiri, K., Fukuzawa, A., Chogahara, M., Kondo, N., & Okada, S. (2018). Community intervention to increase neighborhood social network among Japanese older adults. Geriatrics & gerontology international, 18(3), 462-469.

Masumoto, K., Yaguchi, T., Matsuda, H., Tani, H., Tozuka, K., Kondo, N., & Okada, S. (2017). Measurement and visualization of face‐to‐face interaction among community‐dwelling older adults using wearable sensors. Geriatrics & gerontology international, 17(10), 1752-1758.

河崎素乃美, 谷口隆晴, 増本康平, 近藤徳彦,  岡田修一. (2017). 交流ネットワークの構造変化に対するネットワークモデルを用いた統計的検定手法. 日本応用数理学会論文誌, 27(2), 112-146.

河崎素乃美, 谷口隆晴, 増本康平, 近藤徳彦,  岡田修一. (2017). アクティブエイジングプロジェクトにおける住民交流ネットワークの解析. 応用数理, 27(1), 13-20.