By 2-3 months, infants engage in exploration of their own body as it m
oves and acts in the environment. They babble and touch their own body
, attracted and actively involved in investigating the rich intermodal
redundancies, temporal contingencies, and spatial congruence of self-
perception. Recent research is presented, which investigats the spatia
l and temporal determinants of self-perception and action infancy. Thi
s research shows that, in the course of the first weeks of life, infan
ts develop an ability to detect intermodal invariants and regularities
in their sensorimotor experience, which specify themselves as separat
e entities agent in the environment. Recent observations on the detect
ion of intermodal invariants regarding self-produced leg movements and
auditory feedback of sucking by young infants are reported. These obs
ervations demonstrate that, early in development and long before mirro
r self-recognition, infants develop a perceptual ability to specify th
emselves. It is tentatively proposed that young infants' propensity to
engage in self-perception and systematic exploration of the perceptua
l consequences of their own action plays an important role in the inte
rmodal calibration of the body and is probably at the origin of an ear
ly sense of self: the ecological self.