Making smart social judgments takes time: infants' recruitment of goal information when generating action predictions

Abstract

Previous research has shown that young infants perceive others' actions as structured by goals. One open question is whether the recruitment of this understanding when predicting others' actions imposes a cognitive challenge for young infants. The current study explored infants' ability to utilize their knowledge of others' goals to rapidly predict future behavior in complex social environments and distinguish goal-directed actions from other kinds of movements. Fifteen-month-olds (N = 40) viewed videos of an actor engaged in either a goal-directed (grasping) or an ambiguous (brushing the back of her hand) action on a Tobii eye-tracker. At test, critical elements of the scene were changed and infants' predictive fixations were examined to determine whether they relied on goal information to anticipate the actor's future behavior. Results revealed that infants reliably generated goal-based visual predictions for the grasping action, but not for the back-of-hand behavior. Moreover, response latencies were longer for goal-based predictions than for location-based predictions, suggesting that goal-based predictions are cognitively taxing. Analyses of areas of interest indicated that heightened attention to the overall scene, as opposed to specific patterns of attention, was the critical indicator of successful judgments regarding an actor's future goal-directed behavior. These findings shed light on the processes that support "smart" social behavior in infants, as it may be a challenge for young infants to use information about others' intentions to inform rapid predictions.

Figure 1. Examples of video stimuli.

Depiction of the final video frames for the single familiarization trial in the Grasp and Back-of-Hand conditions, as well as the final video frame for a test trial. AOIs for the person and the objects were identically sized and shaped across conditions for the familiarization trial and for the test trials. The AOIs are depicted here for the test trial image. The individual featured in this figure has given written informed consent (as outlined in PLOS consent form) to publish these images.

Figure 2. Results: Proportion of Predictive Fixations By Condition.

Proportion of predictive fixations to either the prior goal or prior location object, or no prediction across the two test trials.

Figure 3. Results: Proportion of Visual Attention to the Familiarization Trial By Condition.

Proportion of attention distributed across the four relevant action AOIs (i.e., Face, Hand, Prior Goal and Prior Location objects) during the single familiarization trial by condition.

Figure 4. Average Latencies to Generate Predictive Fixations By Condition.

Average latency in seconds to produce a predictive fixation to either the Prior Goal or Prior Location object across conditions.