乳児の注視嗜好における視線依存性の影響

Infants exhibit robust predictive capacities from birth; Most research has focused on how they process externally generated events, leaving unexplored how predictions rooted in their own actions influence attention. We asked whether the source of predictability- self-generated vs. externally structured- affects infants' looking preferences beyond overall predictability. Across two gaze-contingent eye-tracking experiments, we investigated whether infants prefer to look at stimuli whose movements are triggered by their own gaze, or at stimuli that move independently. In Experiment 1 (n = 21, M = 10.11 months), we compared a stimulus whose movement was fully gaze-contingent with a stimulus whose movement pattern was identical to the target, but with a randomly timed onset. In Experiment 2 (n = 22, M = 8.24 months), we presented a gaze-contingent stimulus alongside a moderately predictable but uncontrollable alternative, directly comparing self-generated versus externally structured predictability. In both experiments, infants consistently preferred the gaze-contingent target. This preference was especially pronounced in younger infants and diminished with age. Pupil size analyses supported this interpretation. In Experiment 1, contingent stimuli elicited lower arousal, which is consistent with learned predictability. In contrast, in Experiment 2, pupil responses were similarly low for both stimuli, indicating that their predictability was indeed matched and that contingency itself drove the preference. Overall, these findings suggest that infants are not only attuned to the structure of their environment, but to their own causal influence within it. The results are congruent with the Reinforcement from Sensorimotor Predictability (RSP) framework, which posits that predictable outcomes of self-initiated actions are intrinsically rewarding. Thus, from the earliest months of life, infants appear not only to seek stimulation, but also evidence of their own effectiveness.