Publications of Bonatti, L L.

Precursors of logical reasoning in preverbal human infants

Infants are able to entertain hypotheses about complex events and to modify them rationally when faced with inconsistent evidence. These capacities suggest that infants can use elementary logical representations to frame and prune hypotheses. By presenting scenes containing ambiguities about the identity of an object, here we show that 12- and 19-month-old infants look longer at outcomes that are inconsistent with a logical inference necessary to resolve such ambiguities. At the moment of a potential deduction, infants’ pupils dilated, and their eyes moved toward the ambiguous object when inferences could be computed, in contrast to transparent scenes not requiring inferences to identify the object. These oculomotor markers resembled those of adults inspecting similar scenes, suggesting that intuitive and stable logical structures involved in the interpretation of dynamic scenes may be part of the fabric of the human mind.

Infants anticipate probabilistic but not deterministic outcomes

Recent evidence suggests that preverbal infants’ gaze following can be triggered only if an actor’s head turn is preceded by the expression of communicative intent. Such connectedness between ostensive and referential signals may be uniquely human, enabling infants to effectively respond to referential communication directed to them. In the light of increasing evidence of dogs’ social communicative skills, an intriguing question is whether dogs’ responsiveness to human directional gestures is associated with the situational context in an infant-like manner. Borrowing a method used in infant studies, dogs watched video presentations of a human actor turning toward one of two objects, and their eye-gaze patterns were recorded with an eye tracker. Results show a higher tendency of gaze following in dogs when the human’s head turning was preceded by the expression of communicative intent (direct gaze, addressing). This is the first evidence to show that (1) eye-tracking techniques can be used for studying dogs’ social skills and (2) the exploitation of human gaze cues depends on the communicatively relevant pattern of ostensive and referential signals in dogs. Our findings give further support to the existence of a functionally infant-analog social competence in this species.

Numerical representations and intuitions of probabilities at 12 months

Recent evidence suggests that preverbal infants’ gaze following can be triggered only if an actor’s head turn is preceded by the expression of communicative intent. Such connectedness between ostensive and referential signals may be uniquely human, enabling infants to effectively respond to referential communication directed to them. In the light of increasing evidence of dogs’ social communicative skills, an intriguing question is whether dogs’ responsiveness to human directional gestures is associated with the situational context in an infant-like manner. Borrowing a method used in infant studies, dogs watched video presentations of a human actor turning toward one of two objects, and their eye-gaze patterns were recorded with an eye tracker. Results show a higher tendency of gaze following in dogs when the human’s head turning was preceded by the expression of communicative intent (direct gaze, addressing). This is the first evidence to show that (1) eye-tracking techniques can be used for studying dogs’ social skills and (2) the exploitation of human gaze cues depends on the communicatively relevant pattern of ostensive and referential signals in dogs. Our findings give further support to the existence of a functionally infant-analog social competence in this species.

The probable and the possible at 12 months: intuitive reasoning about the uncertain future

Recent evidence suggests that preverbal infants’ gaze following can be triggered only if an actor’s head turn is preceded by the expression of communicative intent. Such connectedness between ostensive and referential signals may be uniquely human, enabling infants to effectively respond to referential communication directed to them. In the light of increasing evidence of dogs’ social communicative skills, an intriguing question is whether dogs’ responsiveness to human directional gestures is associated with the situational context in an infant-like manner. Borrowing a method used in infant studies, dogs watched video presentations of a human actor turning toward one of two objects, and their eye-gaze patterns were recorded with an eye tracker. Results show a higher tendency of gaze following in dogs when the human’s head turning was preceded by the expression of communicative intent (direct gaze, addressing). This is the first evidence to show that (1) eye-tracking techniques can be used for studying dogs’ social skills and (2) the exploitation of human gaze cues depends on the communicatively relevant pattern of ostensive and referential signals in dogs. Our findings give further support to the existence of a functionally infant-analog social competence in this species.

Pure reasoning in 12-month-old infants as probabilistic inference

Many organisms can predict future events from the statistics of past experience, but humans also excel at making predictions by pure reasoning: integrating multiple sources of information, guided by abstract knowledge, to form rational expectations about novel situations, never directly experienced. Here, we show that this reasoning is surprisingly rich, powerful, and coherent even in preverbal infants. When 12-month-old infants view complex displays of multiple moving objects, they form time-varying expectations about future events that are a systematic and rational function of several stimulus variables. Infants’ looking times are consistent with a Bayesian ideal observer embodying abstract principles of object motion. The model explains infants’ statistical expectations and classic qualitative findings about object cognition in younger babies, not originally viewed as probabilistic inferences.

Intuitions of probabilities shape expectations about the future at 12 months and beyond

Rational agents should integrate probabilities in their predictions about uncertain future events. However, whether humans can do this, and if so, how this ability originates, are controversial issues. Here, we show that 12-month-olds have rational expectations about the future based on estimations of event possibilities, without the need of sampling past experiences. We also show that such natural expectations influence preschoolers’ reaction times, while frequencies modify motor responses, but not overt judgments, only after 4 years of age. Our results suggest that at the onset of human decision processes the mind contains an intuition of elementary probability that cannot be reduced to the encountered frequency of events or elementary heuristics.