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ABSTRACT: 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.
Journal of Experimental Child Psychology 03/2013; · 3.12 Impact Factor
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ABSTRACT: The current study tested whether the purely amodal cue of contingency elicits orientation following behavior in 8-month-old infants. We presented 8-month-old infants with automated objects without human features that did or did not react contingently to the infants' fixations recorded by an eye tracker. We found that an object's occasional orientation toward peripheral targets was reciprocated by a congruent visual orientation following response by infants only when it had displayed gaze-contingent interactivity. Our finding demonstrates that infants' gaze-following behavior does not depend on the presence of a human being. The results are consistent with the idea that, in 8-month-old infants, the detection of contingent reactivity, like other communicative signals, can itself elicit the illusion of being addressed.
Developmental Psychology 09/2011; 47(6):1499-503. · 3.21 Impact Factor
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ABSTRACT: In the research reported here, we investigated whether 18-month-olds would use their own past experience of visual access to attribute perception and consequent beliefs to other people. Infants in this study wore either opaque blindfolds (opaque condition) or trick blindfolds that looked opaque but were actually transparent (trick condition). Then both groups of infants observed an actor wearing one of the same blindfolds that they themselves had experienced, while a puppet removed an object from its location. Anticipatory eye movements revealed that infants who had experienced opaque blindfolds expected the actor to behave in accordance with a false belief about the object's location, but that infants who had experienced trick blindfolds did not exhibit that expectation. Our results suggest that 18-month-olds used self-experience with the blindfolds to assess the actor's visual access and to update her belief state accordingly. These data constitute compelling evidence that 18-month-olds infer perceptual access and appreciate its causal role in altering the epistemic states of other people.
Psychological Science 06/2011; 22(7):878-80. · 4.43 Impact Factor
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ABSTRACT: We propose that the cognitive mechanisms that enable the transmission of cultural knowledge by communication between individuals constitute a system of 'natural pedagogy' in humans, and represent an evolutionary adaptation along the hominin lineage. We discuss three kinds of arguments that support this hypothesis. First, natural pedagogy is likely to be human-specific: while social learning and communication are both widespread in non-human animals, we know of no example of social learning by communication in any other species apart from humans. Second, natural pedagogy is universal: despite the huge variability in child-rearing practices, all human cultures rely on communication to transmit to novices a variety of different types of cultural knowledge, including information about artefact kinds, conventional behaviours, arbitrary referential symbols, cognitively opaque skills and know-how embedded in means-end actions. Third, the data available on early hominin technological culture are more compatible with the assumption that natural pedagogy was an independently selected adaptive cognitive system than considering it as a by-product of some other human-specific adaptation, such as language. By providing a qualitatively new type of social learning mechanism, natural pedagogy is not only the product but also one of the sources of the rich cultural heritage of our species.
Philosophical Transactions of The Royal Society B Biological Sciences 04/2011; 366(1567):1149-57. · 6.40 Impact Factor
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ABSTRACT: Near-infrared spectroscopy (NIRS) is a new and increasingly widespread brain imaging technique, particularly suitable for young infants. The laboratories of the McDonnell Consortium have contributed to the technological development and research applications of this technique for nearly a decade. The present paper provides a general introduction to the technique as well as a detailed report of the methodological innovations developed by the Consortium. The basic principles of NIRS and some of the existing developmental studies are reviewed. Issues concerning technological improvements, parameter optimization, possible experimental designs and data analysis techniques are discussed and illustrated by novel empirical data.
Developmental cognitive neuroscience. 01/2011; 1(1):22-46.
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ABSTRACT: Whether verbal labels help infants visually process and categorize objects is a contentious issue. Using electroencephalography, we investigated whether possessing familiar or novel labels for objects directly enhances 1-year-old children's neural processes underlying the perception of those objects. We found enhanced gamma-band (20-60 Hz) oscillatory activity over the visual cortex in response to seeing objects with labels familiar to the infant (Experiment 1) and those with novel labels just taught to the infant (Experiment 2). No such effect was observed for objects that infants were familiar with but had no label for. These results demonstrate that learning verbal labels modulates how the visual system processes the images of the associated objects and suggest a possible top-down influence of semantic knowledge on object perception.
Journal of Cognitive Neuroscience 12/2010; 22(12):2781-9. · 5.18 Impact Factor
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ABSTRACT: Recent 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.
Developmental Science 11/2010; 13(6):907-12. · 3.89 Impact Factor
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ABSTRACT: Human infants grow up in environments populated by artifacts. In order to acquire knowledge about different kinds of human-made objects, children have to be able to focus on the information that is most relevant for sorting artifacts into categories. Traditional theories emphasize the role of superficial, perceptual features in object categorization. In the case of artifacts, however, it is possible that abstract, non-obvious properties, like functions, may form the basis of artifact kind representations from an early age. Using an object individuation paradigm we addressed the question whether non-verbal communicative demonstration of the functional use of artifacts makes young infants represent such objects in terms of their kinds. When two different functions were sequentially demonstrated on two novel objects as they emerged one-by-one from behind a screen, 10-month-old infants inferred the presence of two objects behind the occluder. We further show that both the presence of communicative signals and causal intervention are necessary for 10-month-olds to generate such a numerical expectation. We also found that communicative demonstration of two different functions of a single artifact generated the illusion of the presence of two objects. This suggests that information on artifact function was used as an indicator of kind membership, and infants expected one specific function to define one specific artifact kind. Thus, contrary to previous accounts, preverbal infants' specific sensitivity to object function underlies, guides, and supports their learning about artifacts.
Cognition 10/2010; 117(1):1-8. · 3.16 Impact Factor
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ABSTRACT: Recently, a series of studies demonstrated false belief understanding in young children through completely nonverbal measures. These studies have revealed that children younger than 3 years of age, who consistently fail the standard verbal false belief test, can anticipate others' actions based on their attributed false beliefs. The current study examined whether children with autism spectrum disorder (ASD), who are known to have difficulties in the verbal false belief test, may also show such action anticipation in a nonverbal false belief test. We presented video stimuli of an actor watching an object being hidden in a box. The object was then displaced while the actor was looking away. We recorded children's eye movements and coded whether they spontaneously anticipated the actor's subsequent behavior, which could only have been predicted if they had attributed a false belief to her. Although typically developing children correctly anticipated the action, children with ASD failed to show such action anticipation. The results suggest that children with ASD have an impairment in false belief attribution, which is independent of their verbal ability.
Development and Psychopathology 05/2010; 22(2):353-60. · 4.40 Impact Factor
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ABSTRACT: Knowledge about the functional status of the frontal cortex in infancy is limited. This study investigated the effects of polymorphisms in four dopamine system genes on performance in a task developed to assess such functioning, the Freeze-Frame task, at 9 months of age. Polymorphisms in the catechol-O-methyltransferase (COMT) and the dopamine D4 receptor (DRD4) genes are likely to impact directly on the functioning of the frontal cortex, whereas polymorphisms in the dopamine D2 receptor (DRD2) and dopamine transporter (DAT1) genes might influence frontal cortex functioning indirectly via strong frontostriatal connections. A significant effect of the COMT valine(1)methionine (Val 158 Met) polymorphism was found. Infants with the Met/Met genotype were significantly less distractible than infants with the Val/Val genotype in Freeze-Frame trials presenting an engaging central stimulus. In addition, there was an interaction with the DAT1 3; variable number of tandem repeats polymorphism; the COMT effect was present only in infants who did not have two copies of the DAT1 10-repeat allele. These findings indicate that dopaminergic polymorphisms affect selective aspects of attention as early as infancy and further validate the Freeze-Frame task as a frontal cortex task.
Developmental Psychology 03/2010; 46(2):404-16. · 3.21 Impact Factor
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ABSTRACT: Despite much research demonstrating infants' abilities to attribute goals to others' actions, it is unclear whether infants can generate on-line predictions about action outcomes, an ability crucial for the human propensity to cooperate and collaborate with others. This lack of evidence is mainly due to methodological limitations restricting the interpretation of behavioral data. Here, we exploited the fact that observers' motor systems are recruited during the observation of goal-directed actions. We presented 9-month-old infants with part of an action. For this action to be interpreted as goal directed, the infants would need to predict an outcome for the action. Measuring the attenuation of the sensorimotor alpha signal during observation of action, we found that infants exhibited evidence of motor activation only if the observed action permitted them to infer a likely outcome. This result provides evidence for on-line goal prediction in infancy, and our method offers a new way to explore infants' cognitive abilities.
Psychological Science 03/2010; 21(3):355-9. · 4.43 Impact Factor
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J. Cognitive Neuroscience. 01/2010; 22:2781-2789.
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ABSTRACT: Many studies have demonstrated that infants can attribute goals to observed actions, whether they are presented live by familiar agents or on a computer screen by abstract figures. However, because most, if not all, of these studies rely on the repeated action presentations typical of infant studies, it is not clear whether infants are simply recognizing the completed action as goal directed, or whether they can productively infer a not-yet-achieved outcome from an ongoing action. We investigated this question by presenting 13-month-old infants with a single animated chasing event. Infants looked longer at the outcome of this action when, given the opportunity, the chaser did not catch the chasee than when it did. Crucially, this result was dependent on whether the action could be construed as efficient with regard to this goal state. This finding suggests the ability to infer the goal of an ongoing novel action and illustrates the productivity of 1-year-olds' action understanding.
Developmental Psychology 11/2009; 45(6):1794-8. · 3.21 Impact Factor
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ABSTRACT: How 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.
Developmental Science 11/2009; 12(6):1013-9. · 3.89 Impact Factor
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ABSTRACT: Ten-month-old infants persistently search for a hidden object at its initial hiding place even after observing it being hidden at another location. Recent evidence suggests that communicative cues from the experimenter contribute to the emergence of this perseverative search error. We replicated these results with dogs (Canis familiaris), who also commit more search errors in ostensive-communicative (in 75% of the total trials) than in noncommunicative (39%) or nonsocial (17%) hiding contexts. However, comparative investigations suggest that communicative signals serve different functions for dogs and infants, whereas human-reared wolves (Canis lupus) do not show doglike context-dependent differences of search errors. We propose that shared sensitivity to human communicative signals stems from convergent social evolution of the Homo and the Canis genera.
Science 10/2009; 325(5945):1269-72. · 31.20 Impact Factor
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ABSTRACT: Certain regions of the human brain are activated both during action execution and action observation. This so-called 'mirror neuron system' has been proposed to enable an observer to understand an action through a process of internal motor simulation. Although there has been much speculation about the existence of such a system from early in life, to date there is little direct evidence that young infants recruit brain areas involved in action production during action observation. To address this question, we identified the individual frequency range in which sensorimotor alpha-band activity was attenuated in nine-month-old infants' electroencephalographs (EEGs) during elicited reaching for objects, and measured whether activity in this frequency range was also modulated by observing others' actions. We found that observing a grasping action resulted in motor activation in the infant brain, but that this activity began prior to observation of the action, once it could be anticipated. These results demonstrate not only that infants, like adults, display overlapping neural activity during execution and observation of actions, but that this activation, rather than being directly induced by the visual input, is driven by infants' understanding of a forthcoming action. These results provide support for theories implicating the motor system in action prediction.
Biology letters 09/2009; 5(6):769-72. · 3.76 Impact Factor
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ABSTRACT: Recent work suggests that a subcortical visual route may mediate rapid orienting towards faces in the visual periphery. We now demonstrate that this orienting bias towards faces shows a temporal-nasal visual field asymmetry of responses, supporting the view that it is mediated by extrageniculate pathways. Upright schematic face-like pattern elicited faster behavioural responses than inverted one in the temporal but not in the nasal hemifield of each eye. This effect occurred for saccades but not for manual responses. The presence of a similar asymmetry of the orienting bias in newborns supports the role of extrageniculate pathways in face detection in both neonates and adults.
Neuroreport 09/2009; 20(15):1309-12. · 1.66 Impact Factor
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ABSTRACT: We propose that human communication is specifically adapted to allow the transmission of generic knowledge between individuals. Such a communication system, which we call 'natural pedagogy', enables fast and efficient social learning of cognitively opaque cultural knowledge that would be hard to acquire relying on purely observational learning mechanisms alone. We argue that human infants are prepared to be at the receptive side of natural pedagogy (i) by being sensitive to ostensive signals that indicate that they are being addressed by communication, (ii) by developing referential expectations in ostensive contexts and (iii) by being biased to interpret ostensive-referential communication as conveying information that is kind-relevant and generalizable.
Trends in Cognitive Sciences 05/2009; 13(4):148-53. · 12.59 Impact Factor
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ABSTRACT: Recent studies of infant siblings of children diagnosed with autism have allowed for a prospective approach to examine the emergence of symptoms and revealed behavioral differences in the broader autism phenotype within the early years. In the current study we focused on a set of functions associated with visual attention, previously reported to be atypical in autism.
We compared performance of a group of 9-10-month-old infant siblings of children with autism to a control group with no family history of autism on the 'gap-overlap task', which measures the cost of disengaging from a central stimulus in order to fixate a peripheral one. Two measures were derived on the basis of infants' saccadic reaction times. The first is the Disengagement effect, which measures the efficiency of disengaging from a central stimulus to orient to a peripheral one. The second was a Facilitation effect, which arises when the infant is cued by a temporal gap preceding the onset of the peripheral stimulus, and would orient faster after its onset.
Infant siblings of children with autism showed longer Disengagement latencies as well as less Facilitation relative to the control group. The findings are discussed in relation to how differences in visual attention may relate to characteristics observed in autism and the broader phenotype.
Journal of Child Psychology and Psychiatry 03/2009; 50(5):637-42. · 4.28 Impact Factor
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ABSTRACT: One-year-old infants have a small receptive vocabulary and follow deictic gestures, but it is still debated whether they appreciate the referential nature of these signals. Demonstrating understanding of the complementary roles of symbolic (word) and indexical (pointing) reference provides evidence of referential interpretation of communicative signals. We presented 13-month-old infants with video sequences of an actress indicating the position of a hidden object while naming it. The infants looked longer when the named object was revealed not at the location indicated by the actress's gestures, but on the opposite side of the display. This finding suggests that infants expect that concurrently occurring communicative signals co-refer to the same object. Another group of infants, who were shown video sequences in which the naming and the deictic cues were provided concurrently but by two different people, displayed no evidence of expectation of co-reference. These findings suggest that a single communicative source, and not simply co-occurrence, is required for mapping the two signals onto each other. By 13 months of age, infants appreciate the referential nature of words and deictic gestures alike.
Psychological Science 03/2009; 20(3):347-53. · 4.43 Impact Factor
