Consciousness Before and After Birth

Abstract

AbstractThe emergence of consciousness cannot be read directly from a birth date, a behavioral milestone, or a single neural response. This critical narrative review examines what developmental neuroscience can establish about subjective experience in fetuses, newborns, and young infants, drawing on literature available through 20 October 2026. It distinguishes the capacity for experience from its momentary occurrence, and phenomenal consciousness from the information processing that makes experience reportable. Human neuroanatomy identifies progressively developing candidate substrates, but does not establish a universally accepted gestational threshold. Auditory rule-violation studies provide evidence of hierarchical processing, although influential fetal and early infant findings are exploratory and adult validation shows important limitations in sensitivity and specificity. Visual masking, attention, and recent neonatal prediction experiments reveal unevenly developing capacities rather than an uncomplicated progression toward adult cognition. Functional connectivity and signal complexity characterize neural organization; neither directly measures experience, and overlapping datasets and metric-dependent results limit claims of convergence. Nociceptive brain responses support continuity with later pain processing without making cortical activation a direct assay of subjective pain. The most defensible synthesis favors basic experience in healthy term newborns and increasingly substantial evidence during early infancy, while leaving prenatal experience and its timing substantially less certain. Development is best investigated as an interaction between maturing capacities, changing physiological states, and differentiating contents. Progress requires longitudinal, state-resolved, developmentally calibrated evidence rather than a search for an isolated diagnostic signature.