Abstract

We developed a new eye-tracker based technique to investigate the reactions of one-year-old infants to stimulus contingencies generated by their own incidental leg movements. In a split-screen paradigm, infants were presented with two identical images that could dynamically change location. The motion of the image on one side of the screen was perfectly contingent with the participant’s leg movements, while the image on the other side moved along the same motion coordinates, but was not contingent with the participant’s actions. Replicating earlier results, we found that infants showed more interest in the less predictable non-contingent display, possibly motivated by information-seeking. However, their gaze towards the contingent display triggered larger pupil dilation, suggesting that detecting the high predictability of self-generated contingencies and the corresponding degree of control, manifested also in the reduced level of uncertainty, are rewarding to infants. Thus, the two dissociating measures appear to reflect two relevant functional aspects of contingency exploration and processing, information-seeking and control-seeking, which guide infants’ monitoring of the physical and social environment.