Recent advances in science have led to a reformulation of the role of early experience and have opened new vistas for effective intervention and change. Early experience has a lasting impact on later ability to perceive and adjust to the world. Babies begin life ready to learn any language and many types of faces: by 1 year, they no longer discriminate the sounds of foreign languages or among other race faces. In utero and during nursing, they learn odor preferences. Early experience during a critical period appears essential: when the experience is delayed, perception does not develop normally. Psychosocial processes are also affected: when a baby is neglected, abused, or has no stable attachment figure, there are lifelong consequences. Yet, recent research indicates that these experiential effects are not as irreversible as once thought. The session will review striking findings that illuminate the neurophysiological and molecular mechanisms that underlie opening and closing of critical periods early in life. Then it will show how such detailed explanation can direct interventions that reopen plasticity and enable reversibility later in life. Speakers will present data first from animal work and then explore similar constructs in studies with humans, sampling from a number of domains that are of importance to adaptive human functioning. In all talks, evidence for early critical periods will be presented but coupled with new research identifying the possibility for change later in life.