Bridging the gap between the other and me: the functional role of motor resonance and action effects in infants’ imitation

Abstract

This paper investigates a two-stage model of infants' imitative learning from observed actions and their effects. According to this model, the observation of another person's action activates the corresponding motor code in the infants' motor repertoire (i.e. leads to motor resonance). The second process guiding imitative behavior results from the observed action effects. If the modeled action is followed by a salient action effect, the representation of this effect (i.e. perceptual code) will be associated with the activated motor code. If the infant later aims to obtain the same effect, the corresponding motor program will be activated and the model's action will therefore be imitated. Accordingly, the model assumes that for the imitation of novel actions the modeled action needs to elicit sufficient motor resonance and must be followed by a salient action effect. Using the head touch imitation paradigm, we tested these two assumptions derived from the model. To this end, we manipulated whether the actions demonstrated to the infants were or were not in the motor repertoire, i.e. elicited stronger or less strong motor resonance, and whether they were followed by salient action effects or not. The results were in line with the proposed two-stage model of infants' imitative learning and suggest that motor resonance is necessary, but not sufficient for infants' imitative learning from others' actions and their effects.

Fourteen-Month-Olds Adapt Their Imitative Behavior in Light of a Model’s Constraints

“…No differences in imitation level should occur in the hands-free condition. In contrast, the two-stage model of infant imitation [18] would predict similar imitation rates in both trials in both conditions, as the action effect stays constant across demonstrations and no change takes place between trials which would improve infants' ability to map the observed action onto their own motor repertoire in the second trial.…”

“…This would be in line with the principles of the mentalistic account [14], as the increase in the imitation rate might suggest infants' interpretation of the repeated demonstration of the unusual target action in the second trial as an emphasis on the intentional nature of the modeled action. This increase in imitation rates would, however, not be predicted by the teleological [12], the perceptual distraction account [20], or the two-stage model of infant imitation [18], as the model's rationality, motor action, or the appearance of the blanket did not change between trials. In the hands-occupied condition, the similar imitation rates in the first and second trial within the first 20 seconds provide support for the mentalistic [14] and the teleological account [12] and could also be explained by the two-stage model of infant imitation [18], as the model's physical constraints remained constant.…”

“…This increase in imitation rates would, however, not be predicted by the teleological [12], the perceptual distraction account [20], or the two-stage model of infant imitation [18], as the model's rationality, motor action, or the appearance of the blanket did not change between trials. In the hands-occupied condition, the similar imitation rates in the first and second trial within the first 20 seconds provide support for the mentalistic [14] and the teleological account [12] and could also be explained by the two-stage model of infant imitation [18], as the model's physical constraints remained constant. It contradicts the prediction of the perceptual distraction account [20], as the position of the blanket remained the same across trials, and due to infants' habituation it should have presented a lower level of distraction in the second trial.…”

“…Four theoretical accounts provide an explanation to the behavioral pattern found by Gergely et al [10] (i.e., the teleological account [12], the mentalistic account [14], the two-stage model of infant imitation [18], or the perceptual distraction account [20]). As stated earlier, the current study was not directly aimed at resolving the question which of these accounts is correct.…”

“…Thus, what makes infants imitate novel actions according to this account is the lack of apparent reasons for the model's choice of means. Rather than attributing mental-state understanding to infants and considering selective imitation as being based on a rational decision, Paulus et al [18] argue in their two-stage model of infant imitation that, first, it is the observed action effect that is decisive in whether or not an observed action will be later imitated. Second, they argue that infants' ability to map the observed action onto their own motor repertoire shapes their imitative behavior.…”