Back

The emergence of intentional action in early human infancy

Fujihira, R.; Shinya, Y.; Watanabe, H.; Taga, G.

2025-12-04 neuroscience
10.64898/2025.12.03.691254 bioRxiv
Show abstract

Intention lies at the core of human behavior, allowing flexible and goal-directed interaction with the environment. However, how it emerges in infancy remains poorly understood. Here we show that intentional action can emerge before overt reaching, revealing that 3-month-old infants display pupil dilation preceding self-initiated actions during interaction with a suspended mobile toy. This phasic pupil dilation first appeared after movement onset but gradually shifted to precede it through environmental interaction, reflecting the emergence of action preparation and prediction of action outcomes. This shift also implies that infants are capable of anticipating the timing of their forthcoming movements. Furthermore, the antecedent pupil dilation occurred only with efficient movements characterised by reduced muscle co-contractions. These findings suggest that infants learn to predict outcomes of their own actions and initiate particular movements at self-determined timings, marking the emergence of intentional action.

Matching journals

The top 4 journals account for 50% of the predicted probability mass.

50% of probability mass above

"Similar papers" are the closest papers from that journal in the model's embedding space. They show what the match is built on, but the ranking comes mostly from a classifier over the whole training set, not from these examples alone.