Neural dynamics in human imitation revealed by ERP surface topography

To clarify the neural dynamics in human motor imitation, we examined event-related potentials (ERP) for a reaction time task that required responses to an actor's ¢nger motions with identical motions. Compared with a control task (reaction to an LED illumination), the ERP surface topography in the imitative reaction was di¡erentiated at around 120^200 ms post-cueing, showing an early sensitivity to the response hand over the pre-central region.This result suggested that activities around the motor areas were facilitated in the imitative reaction, which is consistent with recent neuroimaging studies. However, taken together with that there were no di¡erences in reaction times, the early ERP latency of conditional divergence indicated that neural activities related to imitation are visual responses and do not directly lead to motor acceleration. NeuroRepor

'Obsessed with goals': functions and mechanisms of teleological interpretation of actions in humans

Humans show a strong and early inclination to interpret observed behaviours of others as goal-directed actions. We identify two main epistemic functions that this ‘teleological obsession’ serves: on-line prediction and social learning. We show how teleological action interpretations can serve these functions by drawing on two kinds of inference (‘action-to-goal’ or ‘goal-to-action’), and argue that both types of teleological inference constitute inverse problems that can only be solved by further assumptions. We pinpoint the assumptions that the three currently proposed mechanisms of goal attribution (action-effect associations, simulation procedures, and teleological reasoning) imply, and contrast them with the functions they are supposed to fulfil. We argue that while action-effect associations and simulation procedures are generally well suited to serve on-line action monitoring and prediction, social learning of new means actions and artefact functions requires the inferential productivity of teleological reasoning

Beyond rational imitation: learning arbitrary means actions from communicative demonstrations

The principle of rationality has been invoked to explain that infants expect agents to perform the most efficient means action to attain a goal. It has also been demonstrated that infants take into account the efficiency of observed actions to achieve a goal outcome when deciding whether to reenact a specific behavior or not. It is puzzling, however, that they also tend to imitate an apparently suboptimal unfamiliar action even when they can bring about the same outcome more efficiently by applying a more rational action alternative available to them. We propose that this apparently paradoxical behavior is explained by infants’ interpretation of action demonstrations as communicative manifestations of novel and culturally relevant means actions to be acquired, and we present empirical evidence supporting this proposal. In Experiment 1, we found that 14-month-olds reenacted novel arbitrary means actions only following a communicative demonstration. Experiment 2 showed that infants’ inclination to reproduce communicatively manifested novel actions is restricted to behaviors they can construe as goal-directed instrumental acts. The study also provides evidence that infants’ reenactment of the demonstrated novel actions reflects epistemic motives rather than purely social motives. We argue that ostensive communication enables infants to represent the teleological structure of novel actions even when the causal relations between means and end are cognitively opaque and apparently violate the efficiency expectation derived from the principle of rationality. This new account of imitative learning of novel means shows how the teleological stance and natural pedagogy—two separate cognitive adaptations to interpret instrumental versus communicative actions—are integrated as a system for learning socially constituted instrumental knowledge in humans

Do infants provide evidence that the mirror system is involved in action understanding?

The mirror neuron theory of action understanding makes predictions concerning how the limited motor repertoire of young infants should impact on their ability to interpret others’ actions. In line with this theory, an increasing body of research has identified a correlation between infants’ abilities to perform an action, and their ability to interpret that action as goal-directed when performed by others. In this paper, I will argue that the infant data does by no means unequivocally support the mirror neuron theory of action understanding and that alternative interpretations of the data should be considered. Furthermore, some of this data can be better interpreted in terms of an alternative view, which holds that the role of the motor system in action perception is more likely to be one of enabling the observer to predict, after a goal has been identified, how that goal will be attained

Goal representation in the infant brain

It is well established that, from an early age, human infants interpret the movements of others as actions directed towards goals. However, the cognitive and neural mechanisms which underlie this ability are hotly debated. The current study was designed to identify brain regions involved in the representation of others’ goals early in development. Studies with adults have demonstrated that the anterior intraparietal sulcus (aIPS) exhibits repetition suppression for repeated goals and a release from suppression for new goals, implicating this specific region in goal representation in adults. In the current study, we used a modified paired repetition suppression design with 9-month-old infants to identify which cortical regions are suppressed when the infant observes a repeated goal versus a new goal. We find a strikingly similar response pattern and location of activity as had been reported in adults; the only brain region displaying significant repetition suppression for repeated goals and a release from suppression for new goals was the left anterior parietal region. Not only does our data suggest that the left anterior parietal region is specialized for representing the goals of others’ actions from early in life, this demonstration presents an opportunity to use this method and design to elucidate the debate over the mechanisms and cues which contribute to early action understanding

Reasoning about Instrumental and Communicative Agency in Human Infancy

Theoretical rationality and practical rationality are, respectively, properties of an individual's belief system and decision system. While reasoning about instrumental actions complies with practical rationality, understanding communicative actions complies with the principle of relevance. Section 2 reviews the evidence showing that young infants can reason about an agent's instrumental action by representing her subjective motivations and the episodic contents of her epistemic states (including false beliefs).demonstration as a communicative, not an instrumental, action. Section 4 reviews the evidence for natural pedagogy, a species-unique social communicative learning mechanism that exploits human infants' receptivity to ostensive-communicative signals and enables infants to acquire kind-wide generalizations from the nonverbal demonstrations of communicative agents. We argue that the essentialist bias that has been shown to be involved in children's concepts of natural kinds also applies to infants' concepts of artifacts. We further examine how natural pedagogy may also boost inductive learning in human infancy. Section 3 reviews the evidence showing special sensitivity in young human infants to some ostensive behavioral signals encoding an agent's communicative intention. We also address the puzzle of imitative learning of novel means actions by 1-year olds and argue that it can be resolved only by assuming that the infant construes the model'

Moving Just Like You: Motor Interference Depends on Similar Motility of Agent and Observer

Recent findings in neuroscience suggest an overlap between brain regions involved in the execution of movement and perception of another’s movement. This so-called “action-perception coupling” is supposed to serve our ability to automatically infer the goals and intentions of others by internal simulation of their actions. A consequence of this coupling is motor interference (MI), the effect of movement observation on the trajectory of one’s own movement. Previous studies emphasized that various features of the observed agent determine the degree of MI, but could not clarify how human-like an agent has to be for its movements to elicit MI and, more importantly, what ‘human-like’ means in the context of MI. Thus, we investigated in several experiments how different aspects of appearance and motility of the observed agent influence motor interference (MI). Participants performed arm movements in horizontal and vertical directions while observing videos of a human, a humanoid robot, or an industrial robot arm with either artificial (industrial) or human-like joint configurations. Our results show that, given a human-like joint configuration, MI was elicited by observing arm movements of both humanoid and industrial robots. However, if the joint configuration of the robot did not resemble that of the human arm, MI could longer be demonstrated. Our findings present evidence for the importance of human-like joint configuration rather than other human-like features for perception-action coupling when observing inanimate agents