The ability to sense internal bodily states and navigate external environments may share more cognitive infrastructure than previously assumed — a connection that could reshape how clinicians screen for Alzheimer's disease years before a formal diagnosis. Most early-detection research has focused narrowly on memory or single-domain navigation tests, but a more integrated picture of spatial cognition may prove diagnostically richer.
This cross-sectional study enrolled 53 participants — 28 healthy controls and 25 adults with mild cognitive impairment (MCI) — and subjected them to a multidimensional battery probing three distinct cognitive domains simultaneously. In the interoceptive domain, participants were assessed on accuracy (IAcc), awareness (IAw), and sensibility (ISe) — three separable dimensions of the capacity to perceive one's own internal physiological signals. Spatial cognition was tested via landmark, route, and survey knowledge of a virtual environment. Body representation was parsed into action-oriented and non-action-oriented subtypes. The MCI group showed statistically meaningful deficits specifically in interoceptive accuracy and sensibility, as well as landmark and route knowledge, while survey-level knowledge and action-oriented body representations remained relatively intact.
What makes this finding analytically interesting is the co-occurrence of interoceptive and navigational impairments within the same prodromal population. Interoception is typically studied in psychiatric contexts — anxiety, depression, eating disorders — not in neurodegenerative disease. The insular cortex, which anchors interoceptive processing, also contributes to allocentric spatial mapping, and early Alzheimer's pathology is now understood to affect insular networks earlier than classical hippocampal staging models implied. This convergence supports an emerging view that MCI represents a broad representational collapse, not a memory-specific deficit. The study's key limitation is its small sample size and cross-sectional design, which prevents causal inference or tracking of which deficits emerge first. Replication in larger longitudinal cohorts would be needed before interoceptive accuracy could be considered a validated clinical biomarker. Nonetheless, this is a genuinely novel pairing of measures that opens a productive research direction for multimodal MCI screening.