An integrative model of rational imitation in infancy

It has been proposed that infants selectively imitate based on a rational evaluation of an observed action (Gergely, Bekkering, & Király, 2002). This rational-imitation account has been rejected based on findings which suggested that infant imitation depends on: (a) the similarity between the infant's and the model's body posture; and (b) the presence of action effects (Paulus, Hunnius, Vissers, & Bekkering, 2011). Despite this controversy, we show that both accounts have received empirical support from different fields of research. We propose that both accounts operate on different levels, and we present an integrative model, which combines the two seemingly competing accounts. Motor resonance is perceived as a mechanism that enables infants to imitate, and a rational evaluation of the model's action is conceived as a mechanism that guides infants’ imitative behavior.     

Anticipating action effects recruits audiovisual movement representations in the ventral premotor cortex

When table tennis players anticipate the course of the ball while preparing their motor responses, they not only observe their opponents striking the ball but also listen to events such as the sound of racket–ball contact. Because visual stimuli can be detected more easily when accompanied by a sound, we assumed that complementary sensory audiovisual information would influence the anticipation of biological motion, especially when the racket–ball contact is not presented visually, but has to be inferred from continuous movement kinematics and an abrupt sound. Twenty-six observers were examined with fMRI while watching point-light displays (PLDs) of an opposing table tennis player. Their task was to anticipate the resultant ball flight. The sound was presented complementary to the veracious event or at a deviant time point in its kinematics.Results showed that participants performed best in the complementary condition. Using a region-of-interest approach, fMRI data showed that complementary audiovisual stimulation elicited higher activation in the left temporo-occipital middle temporal gyrus (MTGto), the left primary motor cortex, and the right anterior intraparietal sulcus (aIPS). Both hemispheres also revealed higher activation in the ventral premotor cortex (vPMC) and the pars opercularis of the inferior frontal gyrus (BA 44). Ranking the behavioral effect of complementary versus conflicting audiovisual information over participants revealed an association between the complementary information and higher activation in the right vPMC. We conclude that the recruitment of movement representations in the auditory and visual modalities in the vPMC can be influenced by task-relevant cross-modal audiovisual interaction.     

Action Attenuates the Effect of Visibility on Gesture Rates

Much evidence suggests that semantic characteristics of a message (e.g., the extent to which the message evokes thoughts of spatial or motor properties) and social characteristics of a speaking situation (e.g., whether there is a listener who can see the speaker) both influence how much speakers gesture. However, the Gesture as Simulated Action (GSA) framework (Hostetter & Alibali, 2008 ) predicts that these effects should not be independent but should interact such that the effect of visibility is lessened when a message evokes strong thoughts of action. This study tested this claim by comparing the gesture rates produced by speakers as they described 24 nouns that vary in how strongly they evoke thoughts of action. Further, half of the words were described with visibility between speaker and listener blocked. The results demonstrated a significant interaction as predicted by the GSA framework.     

Expanding the link between core self-evaluations and affective job attitudes

The present study examined the differentiated relationship between core self-evaluations and affective job attitudes. In previous research, job characteristics were proposed to mediate this relationship. However, the facets of the job characteristics model have not yet been assessed separately. In the present study we tested which job characteristics (i.e., skill variety, task identity, task significance, autonomy, and feedback) mediate the relationship between core self-evaluations and job satisfaction as well as organizational commitment in a sample of 199 employees. Results revealed that core self-evaluations were related to job satisfaction and organizational commitment. Task significance was found to mediate these relationships. These findings are discussed with respect to the level on which people regulate their actions.     

What is “Intervention”?

I begin by noting that several theologians and others object to special divine action (divine intervention and action beyond conservation and creation) on the grounds that it is incompatible with science. These theologians are thinking of classical Newtonian science; I argue that in fact classical science is in no way incompatible with special divine action, including miracle. What is incompatible with special divine action is the Laplacean picture, which involves the causal closure of the universe. I then note that contemporary, quantum mechanical science doesn't even initially appear to be incompatible with special divine action. Nevertheless, many who are well aware of the quantum mechanical revolution (including some members of the Special Divine Action Project) still find a problem with special divine action, hoping to find an understanding of it that doesn't involve divine intervention. I argue that their objections to intervention are not sound. Furthermore, it isn't even possible to say what intervention is, given the quantum mechanical framework. I conclude by offering an account of special divine action that isn't open to their objections to intervention.     

The ideomotor approach to imitative learning (IMAIL) in infancy: Challenges and future perspectives

The article presents the ideomotor approach to imitative learning (IMAIL). According to IMAIL, imitation rests on the acquisition of bidirectional action–effect associations through the observations of others’ actions and their sensory consequences. The article first outlines the challenges and demands that motivated the development of the theory. Then, it describes the theory in greater detail and presents empirical evidence supporting IMAIL. Finally, it concludes by discussing challenges and avenues for further research.     

The modulating influence of category size on the classification of exception patterns

Generalization gradients to exception patterns and the category prototype were investigated in two experiments. In Experiment 1, participants first learned categories of large size that contained a single exception pattern, followed by a transfer test containing new instances that had a manipulated similarity relationship to the exception or a nonexception training pattern as well as distortions of the prototype. The results demonstrated transfer gradients tracked the prototype category rather than the feedback category of the exception category. In Experiment 2, transfer performance was investigated for categories varying in size (5, 10, 20), partially crossed with the number of exception patterns (1, 2, 4). Here, the generalization gradients tracked the feedback category of the training instance when category size was small but tracked the prototype category when category size was large. The benefits of increased category size still emerged, even with proportionality of exception patterns held constant. These, and other outcomes, were consistent with a mixed model of classification, in which exemplar influences were dominant with small-sized categories and/or high error rates, and prototype influences were dominant with larger sized categories.     

Can you see me in the snow? Action simulation aids the detection of visually degraded human motion

Using a novel paradigm, we demonstrate that action simulation can directly facilitate ongoing perception of people's movements. Point-light actors (PLAs) representing common human motions were shown embedded in a visual noise reminiscent of “TV snow”. At first, the PLAs were perceived clearly, then occluded from view for a short duration, during which it was hypothesized that a real-time action simulation was generated tracking the motion's course. The PLA then reappeared in motion at variable visibility against the noise, whilst detection thresholds for the reappearance were measured. In the crucial manipulation, the test motion was either temporally congruent with the motion as it would have continued during occlusion, and thus temporally matching the simulation, or temporally incongruent. Detection thresholds were lower for congruent than for incongruent reappearing motions, suggesting that reappearing motion that temporally matched the internal action simulation was more likely to be detected.     

Factors that affect action possibility judgements: Recent experience with the action and the current body state

It has been suggested that action possibility judgements are formed through a covert simulation of the to-be-executed action. We sought to determine whether the motor system (via a common coding mechanism) influences this simulation, by investigating whether action possibility judgements are influenced by experience with the movement task (Experiments 1 and 2) and current body states (Experiment 3). The judgement task in each experiment involved judging whether it was possible for a person's hand to accurately move between two targets at presented speeds. In Experiment 1, participants completed the action judgements before and after executing the movement they were required to judge. Results were that judged movement times after execution were closer to the actual execution time than those prior to execution. The results of Experiment 2 suggest that the effects of execution on judgements were not due to motor activation or perceptual task experience—alternative explanations of the execution-mediated judgement effects. Experiment 3 examined how judged movement times were influenced by participants wearing weights. Results revealed that wearing weights increased judged movement times. These results suggest that the simulation underlying the judgement process is connected to the motor system, and that simulations are dynamically generated, taking into account recent experience and current body state.     

Sources of individual differences in the speed of naming objects and actions: The contribution of executive control

We examined the contribution of executive control to individual differences in response time (RT) for naming objects and actions. Following Miyake et al., executive control was assumed to include updating, shifting, and inhibiting abilities, which were assessed using operation span, task-switching, and stop-signal tasks, respectively. Experiment 1 showed that updating ability was significantly correlated with the mean RT of action naming, but not of object naming. This finding was replicated in Experiment 2 using a larger stimulus set. Inhibiting ability was significantly correlated with the mean RT of both action and object naming, whereas shifting ability was not correlated with the mean naming RTs. Ex-Gaussian analyses of the RT distributions revealed that updating ability was correlated with the distribution tail of both action and object naming, whereas inhibiting ability was correlated with the leading edge of the distribution for action naming and the tail for object naming. Shifting ability provided no independent contribution. These results indicate that the executive control abilities of updating and inhibiting contribute to the speed of naming objects and actions, although there are differences in the way and extent these abilities are involved.