The Mind From Within: Visceral Roots of Human Cognition.

Humans think and act not only with the brain but also with the heart, lungs, gut, and other viscera, such as the bladder, long regarded as primarily vegetative. A fresh wave of experiments is revealing the role of cardiac-cycle phase and baroreceptor firing in perception and social behavior; respiration-locked neural dynamics in attention and learning; and gastrointestinal rhythms and vagal afferents in affect and decision-making. These discoveries are made possible by emerging methods, including ingestible sensors that record gastrointestinal signals in situ during emotional and cognitive tasks, and virtual reality stimuli linked to cardiac and respiratory activity. Expanding on such evidence, this review advances a deep embodiment theory in which visceral states and their conscious perception (interoception) systematically shape memory, consciousness, volitional action, and social cognition. Deep embodiment has implications for economic decision-making, clinical interventions (e.g., organ transplantation), environmental exposures (e.g., air quality), and the design of artificial intelligence (AI) systems that incorporate visceral-like signals for state estimation and adaptive control. Finally, we contrast deep embodiment with brain-reductionist and "shallow" embodiment accounts, arguing that viscera allow a self-centered mode of thinking and influence cognition through specific pathways.