Recent hypotheses regarding the role of the default mode network in the development of a cohesive Self and in environmental monitoring, along with some considerations on Grotstein's concept of projective transidentification, lead the author to reconsider the reasons which have led to the plurality of psychoanalytic models. The solution proposed is the existence of a fundamental frontal-occipital oscillatory dynamic, responsible for the projective-introjective dynamic which is at the basis of psychoanalytic theory and, at the same time, of the development and maintenance of mother-infant syntonization. The oscillatory dynamic, according to this perspective, operates as a “bridge” between two seminal theoretical models of development — the psychoanalytic and the infant research model. A set of neurological hypotheses regarding how maternal interaction may act to modify the infant's projective-introjective dynamic and general brain development are proposed. The different possible modifications of this dynamic offer an explanation of the variety and complexity of psychoanalytic models and the opportunity for a unitary approach, both clinical and theoretical. Given that it is the basis for cerebral activity, the oscillatory dynamic appears intrinsically connected with default mode network's functions of Self cohesiveness and environmental monitoring, suggesting an important interface between Psychoanalysis and the Neurosciences.