How do infants recognize joint attention?

The emergence of joint attention is still a matter of vigorous debate. It involves diverse hypotheses ranging from innate modules dedicated to intention reading to more neuro-constructivist approaches. The aim of this study was to assess whether 12-month-old infants are able to recognize a “joint attention” situation when observing such a social interaction. Using a violation-of-expectation paradigm, we habituated infants to a “joint attention” video and then compared their looking time durations between “divergent attention” videos and “joint attention” ones using a 2 (familiar or novel perceptual component) × 2 (familiar or novel conceptual component) factorial design. These results were enriched with measures of pupil dilation, which are considered to be reliable measures of cognitive load. Infants looked longer at test events that involved novel speaker and divergent attention but no changes in infants’ pupil dilation were observed in any conditions. Although looking time data suggest that infants may appreciate discrepancies from expectations related to joint attention behavior, in the absence of clear evidence from pupillometry, the results show no demonstration of understanding of joint attention, even at a tacit level. Our results suggest that infants may be sensitive to relevant perceptual variables in joint attention situations, which would help scaffold social cognitive development. This study supports a gradual, learning interpretation of how infants come to recognize, understand, and participate in joint attention.     

Two-month-old infants’ sensitivity to allophonic differences

The present study investigated 2-month-olds’ abilities to discriminate allophonic differences that are potentially useful in segmenting fluent speech. Experiment 1 investigated infants’ sensitivity to the kind of distinction that may signal the presence or absence of a word boundary. When tested with the high-amplitude sucking procedure, infants discriminated pairs of items, such as “nitrate” versus “night rate” and “nikrate” versus “nike rate.” By greatly reducing the potential contribution of prosodic differences to these contrasts, Experiment 2 evaluated whether the allophonic differences for /t/ and /r/ were sufficient for infants to distinguish the “nitrate” versus “night rate” pair. Infants distinguished “nitrate” from a cross-spliced version of “night rate,” which differed only in the allophones for /t/ and /r/ that it included. Thus, infants appear to possess one of the prerequisite capacities (i.e., the ability to discriminate allophonic distinctions) necessary to use allophonic information in segmenting fluent speech.     

Serial-position effects in infants’ recognition memory

Preverbal infants (7 months of age) were repeatedly shown a fixed series of photographs of adult female faces. The effects of the order of presentation of a photo (first, middle, or last) and the duration of retention (5 sec, 1 rain, or 5 rain) were subsequently assessed in a probe-recognition test. Both primacy and recency effects were obtained, but there was no evidence of recognition of the face that appeared in the middle of the series. There was also no evidence of recognition of the most recently studied face following the 5-rain retention interval. The bowed serial-position function and labile recency effect match those found in the performance of older subjects in classical verbal learning tasks, and we suggest an automatic process underlying these effects. Our explanation emphasizes differential learning and the context of the items to be remembered.     

Carrying human infants – An evolutionary heritage

We propose that infant carrying is a biological norm for human caregiving, given that human infants have evolved a capacity to cling onto an upright caregiver whose body co-evolved to enable offspring carrying. The origins of this mutual adaptation may date back 4 million years, with the emergence of bipedalism, which precluded the infant horizontal and gravity-supported position on the back of a quadrupedal caregiver. We describe infant cooperative reflexes and behaviors, including the carrying-induced calming response and discuss hypotheses for the invention of infant carrier tools.Carrying involves several physiological and behavioral parent-infant co-adaptations that imply it is an evolutionarily conserved strategy. Epigenetic transmission of reproductive behavior through generations affects the development of the offspring, as well as the mental health of the parent. Carrying might have contributed to the evolution of Hominidae, potentially aiding dexterity, handedness, language acquisition, and social interactions.We review the evolutionary milestones and time points where the infant-caregiver interactions might have changed, exploring infant carrying as it intersects with biological and cultural evolution. We briefly summarize the effects of infant carrying on physiological, epigenetic, and socio-emotional outcomes.     

What do parents talk about to infants?

The content of parents' talk is studied here as expressing their conception of their developing infant, from the initial symbiotic fusion to an individual situtated in space, time and society. The topics parents introduce in their speech to their infant reflect the perception and expectations they have of their baby. The social and parental status of fathers and mothers, and the anticipated role and status of the child- and adult-to-be, and in particular the age and gender of the infant, mediate the choice of topics. Parents' spontaneous speech to 3-month- and 9-month-old infants was studied during a diapering episode, before leaving the day-care centre. Five minutes of such a speech was recorded, and each utterance was assigned to a semantic category (e. g. greetings, comments on diapering, on mood). Sex-typing is already noticeable as early as 3 months of age: comments on the present situation and state are more frequent for girls, and comments about absent persons or events more frequent with boys. Both parents contribute to this effect, fathers more than mothers. With age parents become less concerned with immediate problems and more aware of the infant's own performances. First names are used more for boys than for gilrs. As a whole, boys are considered as individuals earlier than girls.     

Do infants bind mental states to agents?

Recent findings suggest that infants understand others’ preferential choice and can use the perspectives and beliefs of others to interpret their actions. The standard interpretation in the field is that infants understand preferential choice as a dispositional state of the agent. It is possible, however, that these social situations trigger the acquisition of more general, not person-specific knowledge. In a looking-time study we showed an Agent A demonstrating a choice, that only could have been interpreted as preferential based on the perspective (and thus the belief) of the agent, not the observer. Then we introduced a new agent (Agent B), who chose consistently or inconsistently with Agent A; also varying whether Agent B was an adult or a child. Results show that infants expected Agent B (both the adult and the child) to choose as Agent A, but only in the condition where according to Agent A’s knowledge two objects were present in familiarization(confirming previous evidence on the importance of contrastive choice). We interpret these results in the following way: (1) infants do not encode the perspectives of other agents as person-specific sources of knowledge and (2) they learn about the object, rather than the agent’s disposition towards that object. We propose that early theory of mind processes lack the binding of belief content to the belief holder. However, such limitation may in fact serve an important function, allowing infants to acquire information through the perspectives of others in the form of universal access to general information.     

Maternal mind-mindedness over infants’ first three months

Maternal mind-mindedness refers to mothers’ ability to reflect upon their infants’ mental states and respond appropriately. The present study assessed mind-mindedness longitudinally from the newborn period to the infant age of three months. The study is the first to assess maternal mind-mindedness in the infant’s early life prior to three months (one week, one month, two months, three months). To measure maternal mind-mindedness, mothers’ speech to their infants is coded for mental state comments about the infants’ thoughts, desires, and emotions. Appropriate mind-minded comments are judged to accurately reflect the infants’ mental states; non-attuned mind-minded comments are judged to misinterpret the infants’ mental states. Mothers’ individual stability (rank order stability) and group level continuity (mean level of stability across the infant ages) were assessed. Mothers showed modest temporal stability in both appropriate and non-attuned mind-mindedness over the infants’ first three months. The continuity of mind-mindedness showed that appropriate mind-mindedness increased over the infant ages, but non-attuned mind-mindedness showed no change. In infants’ early lives, mothers’ ability to accurately interpret their infants’ mental states is enhanced as the mother-infant relationship develops and infants become more communicative partners.     

Do infants have a sense of fairness?

Two experiments examined infants' expectations about how an experimenter should distribute resources and rewards to other individuals. In Experiment 1, 19-month-olds expected an experimenter to divide two items equally, as opposed to unequally, between two individuals. The infants held no particular expectation when the individuals were replaced with inanimate objects, or when the experimenter simply removed covers in front of the individuals to reveal the items (instead of distributing them). In Experiment 2, 21-month-olds expected an experimenter to give a reward to each of two individuals when both had worked to complete an assigned chore, but not when one of the individuals had done all the work while the other played. The infants held this expectation only when the experimenter could determine through visual inspection who had worked and who had not. Together, these results provide converging evidence that infants in the 2nd year of life already possess context-sensitive expectations relevant to fairness.     

Do infants possess an evolved spider-detection mechanism?

Previous studies with various non-human animals have revealed that they possess an evolved predator recognition mechanism that specifies the appearance of recurring threats. We used the preferential looking and habituation paradigms in three experiments to investigate whether 5-month-old human infants have a perceptual template for spiders that generalizes to real-world images of spiders. A fourth experiment assessed whether 5-month-olds have a perceptual template for a non-threatening biological stimulus (i.e., a flower). The results supported the hypothesis that humans, like other species, may possess a cognitive mechanism for detecting specific animals that were potentially harmful throughout evolutionary history.     

How do deaf infants attain first signs?

In this study the development and alternation of nonreferential gestures were examined longitudinally in terms of the acquisition of Japanese sign language. Parent–child free‐play sessions in their home were videotaped at every monthly visit. Hand activities produced by two deaf infants of deaf parents are described and analyzed. Nonreferential gestures were observed frequently just before the occurrences of the first signs. They consisted of many rhythmic and repetitious movements. Nonreferential gestures became more complex and the number of them also increased as infants grew up. The comparison of nonreferential gestures and first signs revealed the continuity between them in terms of movements. In conclusion, nonreferential gestures are equivalent to a manual analog of vocal babbling.     

Distributed study facilitates infants’ delayed recognition memory

Infants of 5–6 months of age were tested for recognition of briefly presented photographs of faces. The interaction typically obtained with adults, a beneficial effect on retention due to the temporal spacing of study, was obtained with these infants. The results suggest that the distribution effect reflects a fundamental and automatic process of human memory.     

What do infants know about continuous quantity?

We investigated infants' sensitivity to amount of continuous quantity and to change in amount of continuous quantity. Using a habituation procedure, Experiment 1 examined whether 6-month-old infants can distinguish between different amounts of liquid in a container. Infants looked significantly longer at a novel quantity than at the familiar quantity. Using a violation-of-expectation paradigm, Experiment 2 examined whether 9-month-old infants expect a change in amount when liquid is added to a hidden container which is already one-fourth full of liquid. Infants looked significantly longer at the impossible event than at the possible event. These findings indicate that infants are sensitive to amount, calling into question claims that infants have a quantitative mechanism which is exclusive to number.     

Do young infants respond socially to human hands?

This study revealed that 4- and 6-month-old infants produced social-communicative behaviours only in response to faces, and not in response to hands. However, infants’ spontaneous responses to hands were unique in that they scanned the space above the hands, perhaps searching for a face.     

Treating sleep disturbance in infants: What generalizes?

When treating infant sleep problems implementing treatment procedures at bedtime‐only might be easier and more efficient than requiring parents to implement procedures throughout the night, but only if improvements at bedtime generalize to later in the night. This study investigated the immediate and generalized effect of treating bedtime settling problems and later night waking in infants and whether it was parent or child behavior that generalized. Parents recorded sleep problems of seven infants (6–20 months) who exhibited chronic sleep disturbance, then implemented a graduated checking procedure at bedtime‐only (Setting 1). A multiple‐baseline across‐settings and participants design was employed. Immediate (in Setting 1) and any generalized effects (in Setting 2) on wakings and other changes in parent and child behavior were assessed by diary information and all‐night infra‐red video recordings. Clinically significant reductions in sleep problems were evident for five out of seven infants, but these were not consistently observed until parents generalized their use of the procedure throughout the night. There was no evidence that the infants generalized changes in self‐soothing from bedtime to later. It is concluded that changes in infant sleep problems are unlikely to occur unless parents actually alter their management of the problems across all settings in which the problems occur. Copyright © 2008 John Wiley & Sons, Ltd.     

Has infantile sexuality anything to do with infants?

Classical psychoanalytic theory draws many concepts from mental processes that are assumed to arise in the infant and influence the adult mind. Still, psychoanalytic practice with mothers and infants has been integrated but little within general psychoanalytic theory. One reason is that only few analysts have utilized such practice to further theory. Another reason is that infant therapists tend to abandon classical psychoanalytic concepts in favour of attachment concepts. As a result the concept of infantile sexuality, so central to classical theory, plays an unobtrusive role in clinical discussions on infant therapy. The author argues that infantile sexuality plays an important role in many mother-infant disturbances. To function as a clinical concept, it needs to be delineated from attachment and be understood in the context of mother-infant interaction. Two examples are provided; one where the analyst's infantile sexuality emerged in a comment to the infant. Another is a case of breast-feeding problems with a little boy fretting at the breast. This is interpreted as reflecting the mother's infantile sexual conflicts as well as the boy's emerging internalization of them. Thus, to conceptualize such disorders we need to take into account the infantile sexuality in both mother and baby.     

Are infants in the dark about hidden objects?

Infants appear to search for objects hidden by darkness earlier in development than they search for objects hidden by an occluder in the light. However, these two types of search tasks have differed in numerous ways that may have contributed to better performance in the dark (e.g. in whether the hidden objects made sound, in the number of familiarization trials with visible objects). The current studies controlled such incidental differences between search tasks, so that they could be directly compared. Six‐and‐a‐half‐month‐olds received four types of test events, in which either a toy or no toy was presented and then hidden in the dark or under a cloth in the light. Infants searched more often on toy than no‐toy trials in the dark than with a cloth. The advantage in searching for hidden objects in the dark thus appears to be genuine. Theoretical implications are discussed.     

Can chimpanzee infants (Pan troglodytes) form categorical representations in the same manner as human infants (Homo sapiens)?

We directly compared chimpanzee infants and human infants for categorical representations of three global-like categories (mammals, furniture and vehicles), using the familiarization-novelty preference technique. Neither species received any training during the experiments. We used the time that participants spent looking at the stimulus object while touching it as a measure. During the familiarization phase, participants were presented with four familiarization objects from one of three categories (e.g. mammals). Then, they were tested with a pair of novel objects, one was a familiar-category object and another was a novel-category object (e.g. vehicle) in the test phase. The chimpanzee infants did not show significant habituation, whereas human infants did. However, most important, both species showed significant novelty-preference in the test phase. This indicates that not only human infants, but also chimpanzee infants formed categorical representations of a global-like level. Implications for the shared origins and species-specificity of categorization abilities, and the cognitive operations underlying categorization, are discussed.     

Do 10-month-old infants understand others' false beliefs?

As adults, we know that others’ mental states, such as beliefs, guide their behavior and that these mental states can deviate from reality. Researchers have examined whether young children possess adult-like theory of mind by focusing on their understanding about others’ false beliefs. The present research revealed that 10-month-old infants seemed to interpret a person’s choice of toys based on her true or false beliefs about which toys were present. These results indicate that like adults, even preverbal infants act as if they can consider others’ mental states when making inferences about others’ actions.     

Do infants segment words or recurring contiguous patterns?

Eight experiments tested the hypothesis that infants' word segmentation abilities are reducible to familiar sound-pattern parsing regardless of actual word boundaries. This hypothesis was disconfirmed in experiments using the headturn preference procedure: 8.5-month-olds did not mis-segment a consonant-vowel-consonant (CVC) word (e.g., dice) from passages containing the corresponding phonemic pattern across a word boundary (C#VC#; "cold ice"), but they segmented it when the word was really present ("roll dice"). However, they did not segment the real vowel-consonant (VC) word (ice in "cold ice") until 16 months. Yet, at that age, they still did not false alarm on the straddling CVC word. Thus, infants do not simply respond to recurring phonemic patterns. Instead, they are sensitive to both acoustic and allophonic cues to word boundaries. Moreover, there is a sizable developmental gap between consonant- and vowel-initial word segmentation.