This reply article is to be published alongside: Hernik, M., & Southgate, V. (2012). Nine‐months‐old infants do not need to know what the agent prefers in order to reason about its goals: on the role of preference and persistence in infants' goal‐attribution. Developmental Science. doi/10.1111/j.1467‐7687.2012.01151.x
AbstractHuman infants readily interpret others' actions as goal‐directed and their understanding of previous goals shapes their expectations about an agent's future goal‐directed behavior in a changed situation. According to a recent proposal (Luo & Baillargeon, 2005), infants' goal‐attributions are not sufficient to support such expectations if the situational change involves broadening the set of choice‐options available to the agent, and the agent's preferences among this broadened set are not known. The present study falsifies this claim by showing that 9‐month‐olds expect the agent to continue acting towards the previous goal even if additional choice‐options become available for which there is no preference‐related evidence. We conclude that infants do not need to know about the agent's preferences in order to form expectations about its goal‐directed actions. Implications for the role of action persistency and action selectivity are discussed.
AbstractIn recent years there has been a resurgence of interest in the motivations behind, and the function of, infant pointing behaviour. Many studies have converged on the view that early pointing reflects a motivation to share attention and interest with others. Under one view, it is the sharing of attention itself that is the ultimate function of pointing, and is an early manifestation of a uniquely human social cognition that is geared towards cooperation and collaboration. In the current study, we tested an alternative hypothesis in which the goal of pointing is not attention sharing itself, but the information‐laden response that infants tend to receive as a result of sharing attention. If infants indeed point in order to obtain information, their pointing should be modulated by the perceived ability of the other to provide this information. In Experiment 1, 16‐month‐olds who interacted with a demonstrably knowledgeable experimenter pointed significantly more to novel objects than infants who interacted with an ignorant experimenter. In Experiment 2, we confirmed that this finding was due to the perceived competence of the experimenter rather than to the different ways in which the experimenter responded to infants' points. Our results suggest that one function of pointing in infancy is to obtain information from others, and that infants selectively elicit desired information from those whom they perceive could competently provide it.
AbstractSpontaneous Motor Tempo (SMT) is influenced by individual differences in age and body size. We present the first data documenting the SMT of infants from 5 to 37 months of age using a simple drumming task. As in late childhood and adulthood, we predicted that infant SMT would slow across the first years of life. However, we find that older infants drum more quickly than younger infants. Furthermore, studies of adults suggest larger bodies prefer slower rhythms. This relationship may be the product of biomechanical resonance, or effects may be driven by rhythmic experience, such as of locomotion. We used infants, whose body size is dissociated from their predominant experience of locomotion as their parent often carries them, to test this argument. We reveal that infant SMT is predicted by parent, but not own, body size, supporting a passive experience‐based argument, and propose that early rhythm may be set by repetitive vestibular stimulation when carried by the caregiver.
AbstractRecent studies have demonstrated infants' pragmatic abilities for resolving the referential ambiguity of non‐verbal communicative gestures, and for inferring the intended meaning of a communicator's utterances. These abilities are difficult to reconcile with the view that it is not until around 4 years that children can reason about the internal mental states of others. In the current study, we tested whether 17‐month‐old infants are able to track the status of a communicator's epistemic state and use this to infer what she intends to refer to. Our results show that manipulating whether or not a communicator has a false belief leads infants to different interpretations of the same communicative act, and demonstrate early mental state attribution in a pragmatic context.
AbstractHow do children decide which elements of an action demonstration are important to reproduce in the context of an imitation game? We tested whether selective imitation of a demonstrator's actions may be based on the same search for relevance that drives adult interpretation of ostensive communication. Three groups of 18‐month‐old infants were shown a toy animal either hopping or sliding (action style) into a toy house (action outcome), but the communicative relevance of the action style differed depending on the group. For the no prior information group, all the information in the demonstration was new and so equally relevant. However, for infants in the ostensive prior information group, the potential action outcome was already communicated to the infant prior to the main demonstration, rendering the action style more relevant. Infants in the ostensive prior information group imitated the action style significantly more than infants in the no prior information group, suggesting that the relevance manipulation modulated their interpretation of the action demonstration. A further condition (non‐ostensive prior information) confirmed that this sensitivity to new information is only present when the 'old' information had been communicated, and not when infants discovered this information for themselves. These results indicate that, like adults, human infants expect communication to contain relevant content, and imitate action elements that, relative to their current knowledge state or to the common ground with the demonstrator, is identified as most relevant.
Abstract The capacity to take another's perspective appears to be present from early in life, with young infants ostensibly able to predict others' behaviour even when the self and other perspective are at odds. Yet, infants' abilities are difficult to reconcile with the well-known problems that older children have with ignoring their own perspective. Here we show that it is the development of the self-perspective, at around 18 months, that creates a perspective conflict between self and other during a non-verbal perspective-tracking scenario. Using mirror self-recognition as a measure of self-awareness and pupil dilation to index conflict processing, our results show that mirror recognisers perceive greater conflict during action anticipation, specifically in a high inhibitory demand condition, in which conflict between self and other should be particularly salient.
AbstractThe current study probed whether infants understand themselves in relation to others. Infants aged 16–26 months (n = 102) saw their parent wearing a sticker on their forehead or cheek, depending on experimental condition, placed unwitnessed by the child. Infants then received a sticker themselves, and their spontaneous behavior was coded. Regardless of age, from 16 months, all infants who placed the sticker on their cheek or forehead, placed it on the location on their own face matching their parent's placement. This shows that infants as young as 16 months of age have an internal map of their face in relation to others that they can use to guide their behavior. Whether infants placed the sticker on the matching location was related to other measures associated with self‐concept development (the use of their own name and mirror self‐recognition), indicating that it may reflect a social aspect of children's developing self‐concept, namely their understanding of themselves in relation and comparison to others. About half of the infants placed the sticker on themselves, while others put it elsewhere in the surrounding, indicating an additional motivational component to bring about on themselves the state, which they observed on their parent. Together, infants' placement of the sticker in our task suggests an ability to compare, and motivation to align, self and others.
AbstractDuring social interactions we often have an automatic and unconscious tendency to copy or 'mimic' others' actions. The dominant view on the neural basis of mimicry appeals to an automatic coupling between perception and action. It has been suggested that this coupling is formed through associative learning during correlated sensorimotor experience. Although studies with adult participants have provided support for this hypothesis, little is known about the role of sensorimotor experience in supporting the development of perceptual‐motor couplings, and consequently mimicry behaviour, in infancy. Here we investigated whether the extent to which an observed action elicits mimicry depends on the opportunity an infant has had to develop perceptual‐motor couplings for this action through correlated sensorimotor experience. We found that mothers' tendency to imitate their 4‐month‐olds' facial expressions during a parent‐child interaction session was related to infants' facial mimicry as measured by electromyography. Maternal facial imitation was not related to infants' mimicry of hand actions, and instead we found preliminary evidence that infants' tendency to look at their own hands may be related to their tendency to mimic hand actions. These results are consistent with the idea that mimicry is supported by perceptual‐motor couplings that are formed through correlated sensorimotor experience obtained by observing one's own actions and imitative social partners.
AbstractThere are cells in our motor cortex that fire both when we perform and when we observe similar actions. It has been suggested that these perceptual‐motor couplings in the brain develop through associative learning during correlated sensorimotor experience. Although studies with adult participants have provided support for this hypothesis, there is no direct evidence that associative learning also underlies the initial formation of perceptual–motor couplings in the developing brain. With the present study we addressed this question by manipulating infants' opportunities to associate the visual and motor representation of a novel action, and by investigating how this influenced their sensorimotor cortex activation when they observed this action performed by others. Pre‐walking 7–9‐month‐old infants performed stepping movements on an infant treadmill while they either observed their own real‐time leg movements (Contingent group) or the previously recorded leg movements of another infant (Non‐contingent control group). Infants in a second control group did not perform any steps and only received visual experience with the stepping actions. Before and after the training period we measured infants' sensorimotor alpha suppression, as an index of sensorimotor cortex activation, while they watched videos of other infants' stepping actions. While we did not find greater sensorimotor alpha suppression following training in the Contingent group as a whole, we nevertheless found that the strength of the visuomotor contingency experienced during training predicted the amount of sensorimotor alpha suppression at post‐test in this group. We did not find any effects of motor experience alone. These results suggest that the development of perceptual–motor couplings in the infant brain is likely to be supported by associative learning during correlated visuomotor experience.
