I NTERACTION, LIKE REGULATION, structure, motivation, and experience, is a term of such breadth that, without further delineation, it offers little to psychoanalysis. In this paper, I describe the approach I take to a number of topics that are at times subsumed under the rubric of interaction. Two groups of observations are easy to regard as interactions: caregiver-infant exchanges and analyst-analysand exchanges. Even used for these exchanges the term conveys an impression of an observer external to the exchange-one who observes, catalogues, and assigns meanings to (interprets) what caregiver and infant or analyst and analysand are doing with each other. Being, to a degree, outside the exchange can free the observer from the sway of a more intense subjective bias, but that is the rub. The key to observing the ebb and flow of caregiver-infant and analystanalysand exchanges lies in the subjective cuing of one another by affective-cognitive communication. Outside the interaction we can see what the participants are doing, but we often can't see how each is cuing the other to do it. Inside the interaction we can feel the evocative effect of the other's cues and the responsive effect of our own motivation, but we often respond long before we can be reflective about it, and then we generally are reflective only to a limited degree.Dr.