The development of children's and adults' use of kinematic cues for visual anticipation and verbal prediction of action.

Expectations about how others' actions unfold in the future are crucial for our everyday social interactions. The current study examined the development of the use of kinematic cues for action anticipation and prediction in 3-year-olds, 4-year-olds, 10-year-olds, and adults in two experiments. Participants observed a hand repeatedly reaching for either a close or far object.

Differential effects of others' emotional cues on 18-month-olds' preferential reproduction of observed actions.

Infants use others' emotional signals to regulate their own object-directed behavior and action reproduction, and they typically produce more actions after having observed positive as compared to negative emotional cues. This study explored infants' understanding of the referential specificity of others' emotional cues when being confronted with two actions that are accompanied by different emotional displays. Selective action reproduction was measured after 18-month-olds (N = 42) had observed two actions directed at the same object, one of which was modeled with a positive emotional expression and the other with a negative emotional expression.

Using breastfeeding images to promote breastfeeding among young adults.

Young adults' reactions to breastfeeding images were assessed using varied approaches. In Study 1, participants viewed posters from a breastfeeding campaign; many anticipated negative reaction to the campaign. In Study 2, participants viewed novel infant-feeding posters; breastfeeding posters were viewed for less time than bottle-feeding posters, regardless of the task assigned.

Infants' perception of actions and situational constraints: an eye-tracking study.

Rational action understanding requires that infants evaluate the efficiency of a movement in achieving a goal with respect to situational constraints. In contrast, recent accounts have highlighted the impact of perceptual characteristics of the demonstrated movement or constraints to explain infants' behavior in so-called rational imitation tasks. The current study employed eye tracking to investigate how 13- to 15-month-old infants distribute their visual attention to different aspects of an action demonstration.

Infants use compression information to infer objects' weights: examining cognition, exploration, and prospective action in a preferential-reaching task.

The present research used a preferential-reaching task to examine whether 9- and 11-month-olds (n=144) could infer the relative weights of two objects resting on a soft, compressible platform. Experiment 1 established that infants reached preferentially for the lighter of 2 boxes. In Experiments 2-4, infants saw 2 boxes identical except in weight resting on a cotton wool platform.

Infant pupil diameter changes in response to others' positive and negative emotions.

It has been suggested that infants resonate emotionally to others' positive and negative affect displays, and that these responses become stronger towards emotions with negative valence around the age of 12-months. In this study we measured 6- and 12-month-old infants' changes in pupil diameter when presented with the image and sound of peers experiencing happiness, distress and an emotionally neutral state. For all participants the perception of another's distress triggered larger pupil diameters.

Experience matters: 11-month-old infants can learn to use material information to predict the weight of novel objects.

In contrast to previous findings, this study demonstrates that 11-month-old infants are able to learn the relationship between object material and object weight when exploring different objects that provided a systematic covariation of both object features. This guides their action in a subsequent preferential-reaching task.

Generalization gradients and representation modes after absolute and relative discrimination learning in young chickens.

Perceptual relativity has become a central issue in animal psychophysics. In order to assess how the interplay of training experience and stimulus dimension might affect perceptual relativity, we investigated the role of 'absolute' and 'relative' training on the learning and representation of stimuli from two dimensions that might favor absolute or relative encoding to a different degree. Young chicks learned to discriminate 3D-objects by either color or size.

Infants' perception and production of intentional actions.

Human beings act and interact with their social environment. Thus, it is important not only to understand other individuals' actions, but also to control one's own actions. To understand intentional actions one needs to detect goals in the perceived actions of others as well as to control one's own movements in order to achieve these goals through action production.

The link between maternal interaction style and infant action understanding.

The present study investigates whether the maternal interaction style is related to 6-month-old infants' action interpretation. We tested 6-month-olds ability to interpret an unfamiliar human action as goal-directed using a modified version of the paradigm used by Woodward, A. L.

Imitating step by step: a detailed analysis of 9- to 15-month-olds' reproduction of a three-step action sequence.

To investigate what infants around their first birthday learn from observing an action sequence, 9- to 15-month-olds' imitative behavior was compared in three conditions: a demonstration group watched three target action steps and a final outcome, a control group observed only the third step and final outcome, and a baseline group received no demonstration. After a short delay, the demonstration infants of all ages produced more target actions than the control and baseline infants. Moreover, the latency to the first step was shortest in the demonstration condition.

The role of action effects in 12-month-olds' action control: a comparison of televised model and live model.

The present study investigated differences in infant imitation after watching a televised model and a live model and addressed the issue of whether action effects influence infants' action control in both cases. In a 2x2 design, 12-month-old infants observed a live or a televised model performing a three-step action sequence, in which either the 2nd or the 3rd action step was combined with an acoustical action effect. We assumed that infants would use the observed action-effect relations for their own action control in the test phase afterwards.

Action-effect anticipation in infant action control.

There is increasing evidence that action effects play a crucial role in action understanding and action control not only in adults but also in infants. Most of the research in infants focused on the learning of action-effect contingencies or how action effects help infants to infer goals in other persons' actions. In contrast, the present research aimed at demonstrating that infants control their own actions by action-effect anticipation once they know about specific action-effect relations.

The role of action effects in infants' action control.

In adults, the selection and the planning of actions are influenced by the anticipation of desired action effects. However, the role of action effects for action control in infants is still an unresolved issue. One important prerequisite for infants' action control is that infants are able to relate certain movements to certain effects.