Correspondence Between Neocortical Laminar Proportions and Human Physiological Transformation Ages

Recent multi-omics and neuroimaging studies indicate that human physiology does not change uniformly across adulthood but instead exhibits discrete, population-level inflection points. In parallel, the human neocortex is organized into a conserved six-layer laminar architecture established during prenatal and early postnatal development. Although these domains - lifespan physiology and cortical structure - are typically treated as independent, the present study explores whether proportional relationships in neocortical lamination may align with the temporal spacing of physiological transition ages. Using published cytoarchitectonic measurements of neocortical layer thicknesses, proportional normalized boundaries were derived and mapped onto the human lifespan. These predicted boundaries were compared with age-associated inflection points identified in longitudinal and cross-sectional multiomic, multimodal ageing-clock studies, and studies on structural brain topology. The analysis reveals a close numerical correspondence between laminar proportions and established physiological transformation ages. Statistical correlation, regression, and Monte-Carlo analyses indicate that this alignment is unlikely to arise from arbitrary monotonic sequences, though it remains sensitive to variation in reported layer-thickness measurements. The findings do not imply a causal relationship but suggest that long-timescale physiological transitions may reflect broader developmental constraints established early in ontogeny. The results motivate further cross-species, cross-dataset, and longitudinal investigations into whether spatial patterning in cortical development may scale to temporal patterning across the lifespan.