Teleological Reasoning in 4-Month-Old Infants: Pupil Dilations and Contextual Constraints

Four-month-old infants were presented with feeding actions performed in a rational or irrational manner. Infants reacted to the irrational feeding actions by dilating their pupils, but only in the presence of rich contextual constraints. The study demonstrates that teleological processes are online at 4 months of age and illustrates the usefulness of pupil dilations as a measure of social cognitive processes early in infancy

Neural correlates of action perception at the onset of functional grasping

Event-related potentials were recorded while infants observe congruent or incongruent grasping actions at the age when organized grasping first emerges (4-6 months of age). We demonstrate that the event-related potential component P400 encodes the congruency of power grasps at the age of 6 months (Experiment 1) and in 5-month-old infants that have developed the ability to use power grasps (Experiment 2). This effect does not extend to precision grasps, which infants cannot perform (Experiment 3). Our findings suggest that infants' encoding of the relationship between an object and a grasping hand (the action-perception link) is highly specialized to actions and manual configurations of actions that infants are able to perfor

Two-step actions in infancy—the TWAIN model

In this paper, we propose a novel model—the TWAIN model—to describe the durations of two-step actions in a reach-to-place task in human infants. Previous research demonstrates that infants and adults plan their actions across multiple steps. They adjust, for instance, the velocity of a reaching action depending on what they intend to do with the object once it is grasped. Despite these findings and irrespective of the larger context in which the action occurs, current models (e.g., Fitts’ law) target single, isolated actions, as, for example, pointing to a goal. In the current paper, we develop and empirically test a more ecologically valid model of two-step action planning. More specifically, 61 18-month olds took part in a reach-to-place task and their reaching and placing durations were measured with a motion-capture system. Our model explained the highest amount of variance in placing duration and outperformed six previously suggested models, when using model comparison. We show that including parameters of the first action step, here the duration of the reaching action, can improve the description of the second action step, here the duration of the placing action. This move towards more ecologically valid models of action planning contributes knowledge as well as a framework for assessing human machine interactions. The TWAIN model provides an updated way to quantify motor learning by the time these abilities develop, which might help to assess performance in typically developing human children

Look Who's Talking: Pre-Verbal Infants’ Perception of Face-to-Face and Back-to-Back Social Interactions

Four-, 6-, and 11-month old infants were presented with movies in which two adult actors conversed about everyday events, either by facing each other or looking in opposite directions. Infants from 6 months of age made more gaze shifts between the actors, in accordance with the flow of conversation, when the actors were facing each other. A second experiment demonstrated that gaze following alone did not cause this difference. Instead the results are consistent with a social cognitive interpretation, suggesting that infants perceive the difference between face-to-face and back-to-back conversations and that they prefer to attend to a typical pattern of social interaction from 6 months of age

The neural basis of non-verbal communication – enhanced processing of perceived give-me gestures in 9-month-old girls

This study investigated the neural basis of non-verbal communication. Event-related potentials were recorded while twenty-nine 9-month-old infants were presented with a give-me gesture (experimental condition) and the same hand shape but rotated 90 degrees, resulting in a non-communicative hand configuration (control condition). We found different responses in amplitude between the two conditions, captured in the P400 ERP component. Moreover, the size of this effect was modulated by participants’ sex, with girls generally demonstrating a larger relative difference between the two conditions than boys

Occlusion Is Hard: Comparing Predictive Reaching for Visible and Hidden Objects in Infants and Adults

Infants can anticipate the future location of a moving object and execute a predictive reach to intercept the object. When a moving object is temporarily hidden by darkness or occlusion, 6-month-old infants’ reaching is perturbed, but performance on darkness trials is significantly better than occlusion trials. How does this reaching behavior change over development? Experiment 1 tested predictive reaching of 6- and 9-month-old infants. While there was an increase in the overall number of reaches with increasing age, there were significantly fewer predictive reaches during the occlusion compared to visible trials and no age-related changes in this pattern. The decrease in performance found in Experiment 1 is likely to apply not only to the object representations formed by infants but also those formed by adults. In Experiment 2 we tested adults with a similar reaching task. Like infants, the adults were most accurate when the target was continuously visible and performance in darkness trials was significantly better than occlusion trials, providing evidence that there is something specific about occlusion that makes it more difficult than merely lack of visibility. Together, these findings suggest that infants’ and adults’ capacities to represent objects have similar signatures throughout development.Psycholog

Editorial: The Next Step in Developmental Embodiment Research: Integrating Concepts and Methods

[No abstract available