Detection of visual-tactile contingency in the first year after birth.

It is well documented that in the first year after birth, infants are able to identify self-performed actions. This ability has been regarded as the basis of conscious self-perception. However, it is not yet known whether infants are also sensitive to aspects of the self when they cannot control the sensory feedback by means of self-performed actions. Therefore, we investigated the contribution of visual-tactile contingency to self-perception in infants. In Experiment 1, 7- and 10-month-olds were presented with two video displays of lifelike baby doll legs. The infant's left leg was stroked contingently with only one of the video displays. The results showed that 7- and 10-month-olds looked significantly longer at the contingent display than at the non-contingent display. Experiment 2 was conducted to investigate the role of morphological characteristics in contingency detection. Ten-month-olds were presented with video displays of two neutral objects (i.e., oblong wooden blocks of approximately the same size as the doll legs) being stroked in the same way as in Experiment 1. No preference was found for either the contingent or the non-contingent display but our results confirm a significant decrease in looking time to the contingent display compared to Experiment 1. These results indicate that detection of visual-tactile contingency as one important aspect of self-perception is present very early in ontogeny. Furthermore, this ability appears to be limited to the perception of objects that strongly resemble the infant's body, suggesting an early sensitivity to the morphology of one's own body.