Neurophysiological Dynamics of Trust in Human–AI Interaction: A Multi-Level Study of Brain, Hormone, Mind, and Behavior
As artificial intelligence (AI) increasingly participates in human decision environments, understanding how trust emerges and breaks down in human–AI interaction has become a central challenge for information systems research. While prior work has predominantly focused on behavioral measures, the underlying neurophysiological mechanisms of trust remain largely unexplored. In this study, we investigated the multi-level dynamics of trust during face-to-face interaction with an embodied intelligent agent. Participants engaged in decision-making tasks with a humanoid robot while neural activity was recorded using functional near-infrared spectroscopy, salivary oxytocin levels were assessed, and self-reported trust and behavioral influence were measured. We experimentally manipulated system reliability (congruent vs. erroneous decisions) and social expressiveness (animated vs. stationary behavior). Results demonstrated that reliability constitutes the primary foundation of trust: agent errors significantly reduced both reported trust and behavioral influence. Social expressiveness modulated these effects. Animated agents elicited stronger prefrontal activation and enhanced neural–hormonal coupling. Notably, elevated oxytocin levels were associated with reduced trust and diminished behavioral influence when expressive agents committed errors, indicating a context-sensitive vigilance response rather than a simple affiliative bonding mechanism. Together, these findings establish a multi-level neurophysiological framework for understanding trust in human–AI interaction and reveal a critical design trade-off between social expressiveness and trust robustness in intelligent systems.
Frank Krueger
Dr. Frank Krueger is Professor of Systems Social Neuroscience at George Mason University (GMU), USA, where he leads the Social Cognition and Interaction: Functional Neuroimaging (SCI:FI) Lab and serves as Core Faculty at the Center for Advancing Systems Science and Bioengineering Innovation within the Institute for Biohealth Innovation at GMU. He is also an Honorary Professor of Psychology at the University of Mannheim, Germany. Trained as a psychologist, neuroscientist, and physicist, Dr. Krueger investigates the psychoneurobiological foundations of trust across human–human and human–AI interactions. His research integrates behavioral science, social neuroscience, and neuroergonomics to understand how trust emerges, adapts, and can be designed in increasingly autonomous and digital socio-technical systems. He has authored or co-authored over 240 publications and edited The Neurobiology of Trust (Cambridge University Press). His work has contributed to foundational advances in human–human and human–AI trust, uncovering the neural mechanisms that shape cooperation, norm regulation, and affiliative bonding in increasingly autonomous systems and next-generation AI environments. He serves as Specialty Chief Editor for Frontiers in Social Neuroergonomics and is a member of multiple editorial boards as well as national and international grant review panels. Dr. Krueger is the Founder and President of the TRUST Foundation (Transdisciplinary Research Union for the Study of Trust), a global non-profit initiative advancing transdisciplinary research and collaboration on trust in the age of artificial intelligence and complex socio-technical systems.