Person:

Skerry, Amy

Research on human infants and young children has provided evidence for five systems of core knowledge: knowledge of objects and their motions; of agents and their goal-directed actions; of number and the operations of arithmetic; of places in the navigable layout and their distances and directions from one another; and of geometrical forms and their length and angular relations. This chapter examines this knowledge hypothesis by considering each of its three claims: that infants' knowledge is guided by systems; that the systems are at the core of mature reasoning in these domains; and that these systems' computations give rise to knowledge. It reviews how investigating boundary conditions and signature limits allowed the discovery and exploration of these systems across ages, species, and cultures. It suggests that understanding the nature of infants' social reasoning abilities will require a similar effort. The ways such an approach could help to clarify current theories of human social cognitive development are discussed.

Do infants learn to interpret others’ actions through their own experience producing goal-directed action, or does some knowledge of others’ actions precede first-person experience? Several studies report that motor experience enhances action understanding, but the nature of this effect is not well understood. The present research investigates what is learned during early motoric production, and it tests whether knowledge of goal-directed actions, including an assumption that actors maximize efficiency given environmental constraints, exists before experience producing such actions. Three-month-old infants (who cannot yet effectively reach for and grasp objects) were given novel experience retrieving objects that rested on a surface with no barriers. They were then shown an actor reaching for an object over a barrier and tested for sensitivity to the efficiency of the action. These infants showed heightened attention when the agent reached inefficiently for a goal object; in contrast, infants who lacked successful reaching experience did not differentiate between direct and indirect reaches. Given that the infants could reach directly for objects during training and were given no opportunity to update their actions based on environmental constraints, the training experience itself is unlikely to have provided a basis for learning about action efficiency. We suggest that infants apply a general assumption of efficient action as soon as they have sufficient information (possibly derived from their own action experience) to identify an agent’s goal in a given instance.

Humans can recognize others’ emotions based on overt cues such as facial expressions, affective vocalizations, or body posture, or by recruiting an abstract, causal theory of the conditions that tend to elicit different emotions. Whereas previous research has investigated the recognition of emotion in specific perceptual modalities (e.g. facial expressions), this dissertation focuses on the abstract representations that relate observable reactions to their antecedent causes. A combination of neuroimaging, behavioral, and developmental methods are used to shed light on the mechanisms that support various forms of emotion attribution, and to elucidate the core features or dimensions that structure the space of emotions we represent. Chapter 1 identifies brain regions that contain information about emotional valence conveyed either via facial expressions and or via animations depicting abstract situational information. These data reveal regions with modality-specific representations of emotional valence (i.e. patterns of activity that discriminate only positive versus negative facial expressions), as well as modality-independent representations: in medial prefrontal cortex (MPFC), the valence representation generalizes across stimuli, indicating a common neural code that abstracts away from specific perceptual features and is invariant to different forms of evidence. Building on evidence that young infants discriminate and respond to the emotional expressions of others, Chapter 2 investigates whether infants also represent these expressions in relation to the situations that elicit them. The results of several experiments demonstrate that infants within their first year of life have expectations about how facial and vocal displays of emotion relate to the valence of events that precede them. Whereas Chapters 1 and 2 focus on a simple binary distinction between positive and negative affect, Chapter 3 investigates a space of more fine-grained discriminations (e.g. someone feeling proud vs. grateful). A combination of multi- voxel pattern analyses and representational similarity analyses reveal brain regions containing abstract and high-dimensional representations of attributed emotion. Moreover, a set of causal features (encoding properties of eliciting events that vary between different emotions) outperforms more primitive dimensions in capturing neural similarities within these regions. Together, these studies provide a newly detailed characterization of the representations that structure emotion attribution, including their development and neural basis.