How infants process addition and subtraction events

Three experiments are described that assess 5‐month‐old infants’ processing of addition and subtraction events similar to those reported by Wynn (1992a ). In Experiment 1, prior to each test trial, one group of infants was shown an addition event (1 + 1) while another group was shown a subtraction event (2 ? 1). On test trials, all infants were shown outcomes of 0, 1, 2 and 3. The results seemed to require one of two dual‐process models. One such model assumed that the infants could add and subtract but also had a tendency to look longer when more items were on the stage. The other model assumed that infants had a preference for familiarity along with the tendency to look longer when more items were on the stage. Experiments 2 and 3 examined the assumptions made by these two models. In Experiment 2, infants were given only the test trials they had received in Experiment 1. Thus, no addition and subtraction or familiarity was involved. In Experiment 3 infants were familiarized to either one or two items prior to each test trial, but experienced no actual addition or subtraction. The results of these two experiments support the familiarity plus more items to look at model more than the addition and subtraction plus more items to look at model. Taken together, these three experiments shed doubt on Wynn’s (1992a ) assertion that 5‐month‐old infants can add and subtract. Instead they indicate the importance of familiarity preferences and the fact that one should be cautious before assuming that young infants have sophisticated numerical abilities.     

The relationship between attention and deferred imitation in 12-month-old infants

Imitation is a frequent behavior in the first years of life, and serves both a social function (e.g., to interact with others) and a cognitive function (e.g., to learn a new skill). Infants differ in their temperament, and temperament might be related to the dominance of one function of imitation. In this study, we investigated whether temperament and deferred imitation are related in 12-month-old infants. Temperament was measured via the Infant Behavior Questionnaire Revised (IBQ-R) and parts of the Laboratory Temperament Assessment Battery (Lab-TAB). Deferred imitation was measured via the Frankfurt Imitation Test for 12-month-olds (FIT-12). Regression analyses revealed that the duration of orienting (IBQ-R) and the latency of the first look away in the Task Orientation task (Lab-TAB) predicted the infants’ imitation score. These results suggest that attention-related processes may play a major role when infants start to imitate.     

The reliability of a model influences 14-month-olds’ imitation

Human infants have an enormous amount to learn from others to become full-fledged members of their culture. Thus, it is important that they learn from reliable, rather than unreliable, models. In two experiments, we investigated whether 14-month-olds (a) imitate instrumental actions and (b) adopt the individual preferences of a model differently depending on the model’s previous reliability. Infants were shown a series of videos in which a model acted on familiar objects either competently or incompetently. They then watched as the same model demonstrated a novel action on an object (imitation task) and preferentially chose one of two novel objects (preference task). Infants’ imitation of the novel action was influenced by the model’s previous reliability; they copied the action more often when the model had been reliable. However, their preference for one of the novel objects was not influenced by the model’s previous reliability. We conclude that already by 14 months of age, infants discriminate between reliable and unreliable models when learning novel actions.     

Does contingency in adults’ responding influence 12-month-old infants’ social referencing?

In two experiments we examined the influence of contingent versus non-contingent responding on infant social referencing behavior. EXPERIMENT 1: Forty 12-month-old infants were exposed to an ambiguous toy in a social referencing situation. In one condition an unfamiliar adult who in a previous play situation had responded contingently to the infant’s looks gave the infant positive information about the toy. In the other condition an unfamiliar adult who previously had not responded contingently delivered the positive information. EXPERIMENT 2: Forty-eight 12-month-old infants participated in Experiment 2. In this experiment it was examined whether the familiarity of the adult influences infants’ reactions to contingency in responding. In one condition a parent who previously had responded contingently to the infant’s looks provided positive information about the ambiguous toy, and in the other condition a parent who previously had not responded contingently provided the positive information. The infants looked more at the contingent experimenter in Experimenter 1, and also played more with the toy after receiving positive information from the contingent experimenter. No differences in looking at the parent and in playing with the toy were found in Experiment 2. The results indicate that contingency in responding, as well as the familiarity of the adult, influence infants’ social referencing behavior.     

Does contingency in adults’ responding influence 12-month-old infants’ social referencing?

In two experiments we examined the influence of contingent versus non-contingent responding on infant social referencing behavior. EXPERIMENT 1: Forty 12-month-old infants were exposed to an ambiguous toy in a social referencing situation. In one condition an unfamiliar adult who in a previous play situation had responded contingently to the infant’s looks gave the infant positive information about the toy. In the other condition an unfamiliar adult who previously had not responded contingently delivered the positive information. EXPERIMENT 2: Forty-eight 12-month-old infants participated in Experiment 2. In this experiment it was examined whether the familiarity of the adult influences infants’ reactions to contingency in responding. In one condition a parent who previously had responded contingently to the infant’s looks provided positive information about the ambiguous toy, and in the other condition a parent who previously had not responded contingently provided the positive information. The infants looked more at the contingent experimenter in Experimenter 1, and also played more with the toy after receiving positive information from the contingent experimenter. No differences in looking at the parent and in playing with the toy were found in Experiment 2. The results indicate that contingency in responding, as well as the familiarity of the adult, influence infants’ social referencing behavior.     

Long-term memory,forgetting, and deferred imitation in 12-month-old infants

Long-term recall memory, as indexed by deferred imitation, was assessed in 12-month-old infants. Independent groups of infants were tested after retention intervals of 3 min, 1 week and 4 weeks. Deferred imitation was assessed using the ‘observation-only’ procedure in which infants were not allowed motor practice on the tasks before the delay was imposed. Thus, the memory could not have been based on re-accessing a motor habit, because none was formed in the first place. After the delay, memory was assessed either in the same or a different environmental context from the one in which the adult had originally demonstrated the acts. In Experiments 1 and 3, infants observed the target acts while in an unusual environment (an orange and white polka-dot tent), and recall memory was tested in an ordinary room. In Experiment 2, infants observed the target acts in their homes and were tested for memory in a university room. The results showed recall memory after all retention intervals, including the 4 week delay, with no effect of context change. Interestingly, the forgetting function showed that the bulk of the forgetting occurred during the first week. The findings of recall memory without motor practice support the view that infants as young as 12 months old use a declarative (nonprocedural) memory system to span delay intervals as long as 4 weeks.     

Preverbal children with autism understand the intentions of others

There is a ‘theory of mind’ theory of autism. Meltzoff has recently developed a procedure that gives a nonverbal assessment of ‘theory of mind’. A group of children with autism and a matched control group of normally developing infants were given three of Meltzoff’s tasks and three conventional, gestural imitation tasks. The children with autism showed the expected deficits on gestural imitation, but were significantly better than the normally developing infants on the Meltzoff tasks. The implications of these results for a number of theoretical issues are discussed.     

面孔可爱度和客观熟悉度对婴儿面孔注意偏向效应的影响

近年来, 研究发现, 与成人面孔和其他社会性刺激相比, 成人对婴儿面孔表现出更多的注意偏向。本研究利用点探测范式, 结合眼动技术, 探讨了面孔可爱度和熟悉度对婴儿面孔注意偏向效应的影响。行为结果表明, 成人对高可爱度的婴儿面孔的反应时注意偏向更强; 眼动结果发现, 高可爱度的婴儿面孔的首注视时间偏向和总注视时间偏向更强, 表现为注意维持模式, 并且, 这一效应只出现在低熟悉度条件下; 而在可爱度评分上, 高熟悉度的婴儿面孔的可爱度评分显著高于低熟悉度的婴儿面孔。结果表明, 在低熟悉度条件下, 可爱度才会影响成人对婴儿面孔注意偏向效应; 在偏好行为上, 对婴儿面孔的主观评定和观看行为上可能存在分离的情况。     

Changes in infant visual attention when observing repeated actions

Infants’ early visual preferences for faces, and their observational learning abilities, are well-established in the literature. The current study examines how infants’ attention changes as they become increasingly familiar with a person and the actions that person is demonstrating. The looking patterns of 12- (n = 61) and 16-month-old infants (n = 29) were tracked while they watched videos of an adult presenting novel actions with four different objects three times. A face-to-action ratio in visual attention was calculated for each repetition and summarized as a mean across all videos. The face-to-action ratio increased with each action repetition, indicating that there was an increase in attention to the face relative to the action each additional time the action was demonstrated. Infant’s prior familiarity with the object used was related to face-to-action ratio in 12-month-olds and initial looking behavior was related to face-to-action ratio in the whole sample. Prior familiarity with the presenter, and infant gender and age, were not related to face-to-action ratio. This study has theoretical implications for face preference and action observations in dynamic contexts.     

Eighteen-month-old human infants show intensive development in comprehension of different types of pointing gestures

This study explored children’s development in comprehending four types of pointing gestures with different familiarity. Our aim was to highlight human infants’ pointing comprehension abilities under the same conditions used for various animal species. Sixteen children were tested longitudinally in a two-choice task from 1 year of age. At the age of 12 and 14 months, infants did not exceed chance level with either of the gestures used. Infants were successful with distal pointing and long cross-pointing at the age of 16 months. By the age of 18 months, infants showed a high success rate with the less familiar gestures (forward cross-pointing and far pointing) as well. Their skills at this older age show close similarity with those demonstrated previously by dogs when using exactly the same testing procedures. Our longitudinal studies also revealed that in a few infants, the ability to comprehend pointing gestures is already apparent before 16 months of age. In general, we found large individual variation. This has been described for a variety of cognitive skills in human development and seems to be typical for pointing comprehension as well.     

The role of sensorimotor experience in the development of mimicry in infancy

During 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.     

Emotional facial expressions affect visual rule learning in 7- to 8-month-old infants

Rule learning (RL) is an implicit learning mechanism that allows infants to detect and generalize rule-like repetition-based patterns (such as ABB and ABA) from a sequence of elements. Increasing evidence shows that RL operates both in the auditory and the visual domain and is modulated by the perceptual expertise with the to-be-learned stimuli. Yet, whether infants’ ability to detect a high-order rule from a sequence of stimuli is affected by affective information remains a largely unexplored issue. Using a visual habituation paradigm, we investigated whether the presence of emotional expressions with a positive and a negative value (i.e., happiness and anger) modulates 7- to 8-month-old infants’ ability to learn a rule-like pattern from a sequence of faces of different identities. Results demonstrate that emotional facial expressions (either positive and negative) modulate infants’ visual RL mechanism, even though positive and negative facial expressions affect infants’ RL in a different manner: while anger disrupts infants’ ability to learn the rule-like pattern from a face sequence, in the presence of a happy face infants show a familiarity preference, thus maintaining their learning ability. These findings show that emotional expressions exert an influence on infants’ RL abilities, contributing to the investigation on how emotion and cognition interact in face processing during infancy.     

Homo imitans or homo provocans? Human imprinting model of neonatal imitation

Searching for the mechanism of neonatal imitation resulted in the discovery of neonatal initiative capacity, here called “provocation”. Newborns spontaneously produced previously imitated gestures while waiting for the experimenter’s response. A psychophysiological analysis revealed that imitation was accompanied by heart rate increase while gesture initiation was accompanied by heart rate deceleration, suggesting different underlying mechanisms. Results imply that infants are not only capable of responding to a model movement by imitating, but that they also have the capacity to provoke an imitative response, thus sustaining an interaction. These findings may constitute a laboratory demonstration of the first dialogue and, according to our hypothetical model, they represent how human imprinting begins.     

Mother versus stranger: a triadic situation of imitation at the end of the first year of life

This study presents two experiments investigating 8‐ and 12‐month‐old infants' imitative behaviour. Seventy‐two 8‐month‐olds and seventy‐two 12‐month‐olds were observed in a triadic situation which included their mother and a stranger. Depending on the condition, either the mother or the stranger acted as the demonstrator and either stayed close or withdrew after the demonstration, during the response period. In addition to imitative acts, visual exploration and smiles addressed, respectively, to each partner were computed. Results showed that at both ages, neither the familiarity nor the position of the partner has an effect on the number of target gestures that are imitated. At 12 months, infants looked and smiled more at the stranger when he demonstrated target actions but no difference was found when the mother acted as demonstrator. Moreover, 12‐month‐old infants looked more at the demonstrating partner immediately after their first imitation. At 8 months, infants paid more attention to the stranger in all conditions except when the mother performed the target actions and moved away, a pattern that suggests a referencing to the mother. Results from the gaze and smile variables suggest that with age different motivations (social contact, exploration of objects) induce imitation. Copyright © 2003 John Wiley & Sons, Ltd.     

Vocal imitation between mothers and infants

The aim of the present mixed cross-sectional and longitudinal study was to observe and describe some aspects of vocal imitation in natural mother-infant interaction. Specifically, maternal imitation of infant utterances was observed in relation to the imitative modeling, mirrored equivalence, and social guided learning models of infant speech development. Nine mother-infant dyads were audio-video recorded. Infants were recruited at different ages between 6 and 11 months and followed for 3 months, providing a quasi-longitudinal series of data from 6 through 14 months of age. It was observed that maternal imitation was more frequent than infant imitation even though vocal imitation was a rare maternal response. Importantly, mothers used a range of contingent and noncontingent vocal responses in interaction with their infants. Mothers responded to three-quarters of their infant's vocalizations, including speech-like and less mature vocalization types. The infants’ phonetic repertoire expanded with age. Overall, the findings are most consistent with the social guided learning approach. Infants rarely imitated their mothers, suggests a creative self-motivated learning mechanism that requires further investigation.     

Imitation from 12 to 24 months in autism and typical development: a longitudinal Rasch analysis

The development of imitation during the second year of life plays an important role in domains of sociocognitive development such as language and social learning. Deficits in imitation ability in persons with autism spectrum disorder (ASD) from toddlerhood into adulthood have also been repeatedly documented, raising the possibility that early disruptions in imitation contribute to the onset of ASD and the deficits in language and social interaction that define the disorder. This study prospectively examined the development of imitation between 12 and 24 months of age in 154 infants at familial risk for ASD and 78 typically developing infants who were all later assessed at 36 months for ASD or other developmental delays. The study established a developmental measure of imitation ability and examined group differences over time, using an analytic Rasch measurement model. Results revealed a unidimensional latent construct of imitation and verified a reliable sequence of imitation skills that was invariant over time for all outcome groups. Results also showed that all groups displayed similar significant linear increases in imitation ability between 12 and 24 months and that these increases were related to individual growth in both expressive language and ratings of social engagement but not in fine motor development. The group of children who developed ASD by age 3 years exhibited delayed imitation development compared with the low-risk typical outcome group across all time-points, but were indistinguishable from other high-risk infants who showed other cognitive delays not related to ASD.     

How do mothers signal shared feeling‐states to their infants? An investigation of affect attunement and imitation during the first year of life

The present study examined how mothers signal shared feeling-states to their infants. Affect attunement and imitation were investigated cross-culturally in 39 mother-infant dyads from Sweden (N = 22) and the former Yugoslavia (N = 17) during the first year of life. Video-recordings of playful interaction between mothers and their infants were analysed using the Affect Attunement Protocol. A significant negative association between imitation and age was found, while there was a significant positive association between affect attunement and age. Single occurrences of affect attunement appeared already at two or three months of age, and by 6 months of age episodes of affect attunement were more common than imitation. Frequencies of imitation and affect attunement were similar cross-culturally and in terms of gender, although there was a significant interaction between age and gender. The results suggest that the signalling of shared feeling-states is not a static process. Mothers do not signal shared feeling-states in the same manner at different ages. Imitation is the most important process during the earliest months, but is superseded by affect attunement earlier than previously thought. The functional implications of this developmental variation are discussed.     

Mediated imitation in 6-month-olds: remembering by association

In two experiments with 72 6-month-olds, we examined whether associating an imitation task with an operant task affects infants' memory for either task. In Experiment 1, infants who imitated target actions that were modeled for 60 s on a hand puppet remembered them for only 1 day. We hypothesized that if infants associated the puppet imitation task with a longer-remembered operant task, then they might remember it longer too. In Experiment 2, infants learned to press a lever to activate a miniature train-a task 6-month-olds remember for 2 weeks-and saw the target actions modeled immediately afterward. These infants successfully imitated for up to 2 weeks, but only if the train memory was retrieved first. A follow-up experiment revealed that the learned association was bidirectional. This is the first demonstration of mediated imitation in 6-month-olds across two very different paradigms and reveals that associations are an important means of protracting memories.     

Fourteen-month-olds’ imitation is influenced more strongly by a model’s competence than by a model’s certainty

Research has shown that infants are more likely to learn from certain and competent models than from uncertain and incompetent models. However, it is unknown which of these cues to a model’s reliability infants consider more important. In Experiment 1, we investigated whether 14-month-old infants (n = 35) imitate and adopt tool choices selectively from an uncertain but competent compared to a certain but incompetent model. Infants watched videos in which an adult expressed either uncertainty but acted competently or expressed certainty but acted incompetently with familiar objects. In tool-choice tasks, the adult then chose one of two objects to operate an apparatus, and in imitation tasks, the adult then demonstrated a novel action. Infants did not adopt the model’s choice in the tool-choice tasks but they imitated the uncertain but competent model more often than the certain but incompetent model in the imitation tasks. In Experiment 2, 14-month-olds (n = 33) watched videos in which an adult expressed only either certainty or uncertainty in order to test whether infants at this age are sensitive to a model’s certainty. Infants imitated and adopted the tool choice from a certain model more than from an uncertain model. These results suggest that 14-month-olds acknowledge both a model’s competence and certainty when learning novel actions. However, they rely more on a model’s competence than on his certainty when both cues are in conflict. The ability to detect reliable models when learning how to handle cultural artifacts helps infants to become well-integrated members of their culture.     

Deferred imitation in 18-month-olds from two cultural contexts: The case of Cameroonian Nso farmer and German-middle class infants

Imitative learning has been described in naturalistic studies for different cultures, but lab-based research studying imitative learning across different cultural contexts is almost missing. Therefore, imitative learning was assessed with 18-month-old German middle-class and Cameroonian Nso farmer infants – representing two highly different eco-cultural contexts associated with different cultural models, the psychological autonomy and the hierarchical relatedness – by using the deferred imitation paradigm. Study 1 revealed that the infants from both cultural contexts performed a higher number of target actions in the deferred imitation than in the baseline phase. Moreover, it was found that German middle-class infants showed a higher mean imitation rate as they performed more target actions in the deferred imitation phase compared with Cameroonian Nso farmer infants. It was speculated that the opportunity to manipulate the test objects directly after the demonstration of the target actions could enhance the mean deferred imitation rate of the Cameroonian Nso farmer infants which was confirmed in Study 2. Possible explanations for the differences in the amount of imitated target actions of German middle-class and Cameroonian Nso farmer infants are discussed considering the object-related, dyadic setting of the imitation paradigm with respect to the different learning contexts underlying the different cultural models of learning.