Sensitive periods neurobiologically encode environmental experiences to facilitate plasticity and learning in human development. Knowledge of human sensitive periods has largely come from methods developed in animal models and remains limited in many domains. We provide a framework and suite of approaches to study these phenomena in humans to stimulate progress in understanding human sensitive periods. To do so, we evaluate how current research approaches can shed light on different aspects of human sensitive period processes. These approaches comprise environmental manipulations like deprivation and substitution paradigms, pharmacological manipulations, and computational modeling. Finally, we propose three novel approaches rooted in human neuroscience—including impoverished environments, enriched environmental interventions, and individual differences in stress—to motivate future research on sensitive period mechanisms.