Map-based spatial perspective taking reveals frontal late negativity loss and posterior delta gain in mild cognitive impairment.

Spatial disorientation represents a clinically meaningful vulnerability during aging and is an early manifestation along the Alzheimer's disease continuum. Understanding how aging-related central nervous system (CNS) changes affect the neural computations required for spatial perspective taking (SPT) is essential for characterizing early neurodegenerative processes. In this study, older adults with mild cognitive impairment (MCI) and subjective cognitive decline (SCD) completed a simplified map-based SPT paradigm while electroencephalography (EEG) was recorded. Although behavioral accuracy was largely preserved, MCI participants demonstrated globally slower responses. Crucially, high-demand egocentric-allocentric transformations (180°) revealed a marked loss of frontal N400 modulation in MCI, together with increased posterior delta-band synchronization. This pattern indicates an aging-related frontal-posterior reweighting in spatial integration networks, consistent with early compensatory recruitment as frontal conflict-monitoring mechanisms decline. These findings provide mechanistic insight into how aging and MCI jointly alter CNS function during spatial cognition, and they highlight the translational potential of low-burden SPT-EEG paradigms for detecting subtle neurophysiological changes relevant to clinical neurology, geriatric assessment, and the early monitoring of neurodegenerative disease.