Preverbal Infants Research Articles

Preverbal infants produce more protophones with artificial objects compared to natural objects

Protophones are considered to be precursors of speech. These vocalizations have been notably discussed in relation to toys and their importance for developing language skills. However, little is known about how natural objects, compared to artificial objects, may affect protophone production, an approach that could additionally help reconstruct how language evolved. In the current study, we examined protophone production in 58 infants (4–18 months) while interacting with their caregivers when using natural objects, household items, and toys. The infants were recorded in their home environment, in a rural area in Zambia. The results showed that the infants produced significantly fewer protophones when using natural objects than when using household items or toys. Importantly, this pattern was found only for the younger preverbal infants, and there was no indication in the data that the level of caregiver responsiveness differed with regard to the object type. Furthermore, the infants of the present work selected primarily the household items when exposed to both natural objects and household items. These findings suggest that natural objects are less likely to promote protophone production and, consequently, language skill development than artificial objects in preverbal infants, who seem to favor the latter, perhaps due to their features designed for specific functional purposes. Furthermore, these findings provide empirical evidence that the use of complex tools in social interactions may have helped to promote the evolution of language among hominins.

An initial but receding altercentric bias in preverbal infants' memory.

Young learners would seem to face a daunting challenge in selecting to what they should attend, a problem that may have been exacerbated in human infants by changes in carrying practices during human evolution. A novel theory proposes that human infant cognition has an altercentric bias whereby early in life, infants prioritize encoding events that are the targets of others' attention. We tested for this bias by asking whether, when the infant and an observing agent have a conflicting perspective on an object's location, the co-witnessed location is better remembered. We found that 8- but not 12-month-olds expected the object to be at the location where the agent had seen it. These findings suggest that in the first year of life, infants may prioritize the encoding of events to which others attend, even though it may sometimes result in memory errors. However, the disappearance of this bias by 12 months suggests that altercentricism is a feature of very early cognition. We propose that it facilitates learning at a unique stage in the life history when motoric immaturity limits infants' interaction with the environment; at this stage, observing others could maximally leverage the information selection process.

The other side of false belief: Constructing the objectivity of reality

AbstractYoung children appear not to grasp the independence between objective reality and subjective beliefs, as evidenced by their errors on false belief tasks. Whereas decades of research have examined children's developing understanding of the subjectivity of beliefs, however, almost no research has examined the other side of the issue: How do humans come to understand the objectivity of reality, and why is this understanding important? To help address this gap, this article proposes an evolutionary‐developmental account of how the understanding that reality is objective may have emerged in human thinking. Three key steps are highlighted: (i) phylogenetic foundations in great ape competitive mindreading, (ii) ontogenetic foundations in preverbal infant joint attention, and (iii) key experiences of perspectival conflict in linguistic humans. Functionally, the concept of an objective reality facilitated collaborative reasoning and joint decision‐making. To arrive at good joint decisions, individuals needed to recognize that both their own beliefs and others' beliefs could be wrong—with respect to the objective reality.

Number sense at 12 months predicts 4-year-olds' maths skills.

Preverbal infants spontaneously represent the number of objects in collections. Is this 'sense of number' (also referred to as Approximate Number System, ANS) part of the cognitive foundations of mathematical skills? Multiple studies reported a correlation between the ANS and mathematical achievement in children. However, some have suggested that such correlation might be mediated by general-purpose inhibitory skills. We addressed the question using a longitudinal approach: we tested the ANS of 60 12 months old infants and, when they were 4 years old (final N=40), their symbolic math achievement as well as general intelligence and inhibitory skills. Results showed that the ANS at 12 months is a specific predictor of later maths skills independent from general intelligence or inhibitory skills. The correlation between ANS and maths persists when both abilities are measured at four years. These results confirm that the ANS has an early, specific and longstanding relation with mathematical abilities in childhood. RESEARCH HIGHLIGHTS: In the literature there is a lively debate about the correlation between the ANS and maths skills. We longitudinally tested a sample of 60 preverbal infants at 12 months and rested them at 4 years (final sample of 40 infants). The ANS tested at 12 months predicted later symbolic mathematical skills at 4 years, even when controlling for inhibition, general intelligence and perceptual skills. The ANS tested at 4 years remained linked with symbolic maths skills, confirming this early and longstanding relation in childhood.

Six facial prosodic expressions caregivers similarly display to infants and dogs

Parents tend to use a specific communication style, including specific facial expressions, when speaking to their preverbal infants which has important implications for children’s healthy development. In the present study, we investigated these facial prosodic features of caregivers with a novel method that compares infant-, dog- and adult-directed communication. We identified three novel facial displays in addition to the already described three facial expressions (i.e. the ‘prosodic faces’) that mothers and fathers are typically displaying when interacting with their 1–18 month-old infants and family dogs, but not when interacting with another adult. The so-called Special Happy expression proved to be the most frequent face type during infant- and dog-directed communication which always includes a Duchenne marker to convey an honest and intense happy emotion of the speaker. These results suggest that the ‘prosodic faces’ play an important role in both adult-infant and human–dog interactions and fulfil specific functions: to call and maintain the partner’s attention, to foster emotionally positive interactions, and to strengthen social bonds. Our study highlights the relevance of future comparative studies on facial prosody and its potential contribution to healthy emotional and cognitive development of infants.

Ready for Read‐Alouds: 10 Practices for Book‐Sharing with Infants and Toddlers

AbstractExperiences with books before age three predict children's motivation to read (Bus et al., 1995), and can support the development of vocabulary, communication, and symbolic skills (Scarborough, 2001). Sharing books with infants and toddlers is different than reading aloud to older children. For example, it is important to attend more closely to infants' eye gaze and to support toddlers to respond with gestures. This article presents 10 research‐based practices for book‐sharing with infants and toddlers to foster love of reading and emergent literacy skills. For each practice, we provide examples with preverbal infants and newly verbal toddlers. We encourage teachers of reading to use these practices in their interactions with infants and toddlers and to use their role as literacy leaders to share the practices with childcare providers, families, and others who work with this age group.

Two types of genetic reasoning in contemporary psychology and their relevance for education

The paper shows how arguments based on genetics came back in the 1960s. The universalist claims started from the innatism of Chomsky, and gradually extended the idea of preconfigured cognitive systems to several areas. This resulted in the development on new methods towards studying preverbal infants, but also in proposing much leaner prewired core systems. The other revival of genetic ideas in psychology was mainly reraising to classical nature/nurture debates regarding IQ. The new epigenetic theories propose a new synthesis in the frames of developmental science: environmental enrichment fosters the unfolding of genetic based individual differences.

Representations of Abstract Relations in Infancy.

relations are considered the pinnacle of human cognition, allowing for analogical and logical reasoning, and possibly setting humans apart from other animal species. Recent experimental evidence showed that infants are capable of representing the abstract relations same and different, prompting the question of the format of such representations. In a propositional language of thought, abstract relations would be represented in the form of discrete symbols. Is this format available to pre-lexical infants? We report six experiments (N = 192) relying on pupillometry and investigating how preverbal 10- to 12-month-old infants represent the relation same. We found that infants' ability to represent the relation same is impacted by the number of individual entities taking part in the relation. Infants could represent that four syllables were the same and generalized that relation to novel sequences (Experiments 1 and 4). However, they failed to generalize the relation same when it involved 5 or 6 syllables (Experiments 2-3), showing that infants' representation of the relation same is constrained by the limits of working memory capacity. Infants also failed to form a representation equivalent to all the same, which could apply to a varying number of same syllables (Experiments 5-6). These results highlight important discontinuities along cognitive development. Contrary to adults, preverbal infants lack a discrete symbol for the relation same, and rather build a representation of the relation by assembling symbols for individual entities.

A cross-cultural investigation of people's intuitive beliefs about the origins of cognition.

Nature vs. nurture is an enduring theme of studies of the mind. Past studies on American children and adults have revealed a preference for thinking that even fundamental cognitive abilities documented in human infants and non-human species are late-emerging and reliant on learning and nurture. However, little is known about the generalizability of this "intuitive empiricist" belief and what factors may help explain it. Adult participants (N = 600) reported their beliefs about the emergence of several fundamental cognitive abilities demonstrated by preverbal infants. Studies 1A-1C showed that adults from both Japan and the US similarly estimated an older age of onset for cognitive abilities in human children as compared to the findings of cognitive science and consistently attributed acquisition of these abilities to learning rather than innateness in humans, and they made these learning attributions more so for humans than for non-human species. Study 2 showed that participants' beliefs about biological evolution versus creationism were related to their age onset estimates for fundamental cognitive abilities, and their beliefs about the malleability of intelligence were related to participants' explanations of the origin of fundamental cognitive abilities. These findings suggest generalizable preferences for nurture over nature across both Eastern and Western cultures (Japan and the United States), which may be related to people's beliefs about human origins and the power of learning.

Habituation, part II. Rethinking the habituation paradigm

AbstractThe habituation paradigm has been applied to study the development of memory, perception, and other cognitive processes in preverbal infants, making it one of the most prominent experimental paradigms in infant research. However, there are many features of the process of habituation that remain elusive, which results in uncertainty about the best research practices. This article first discusses current practices in habituation research (e.g., the use of habituation criteria) in relation to modelling the process of habituation, revealing several issues that impede progress in the field. To overcome these challenges, we propose to move towards a modelling framework to study critical features of the habituation process. To facilitate this transition, alternative experimental designs are proposed. The article encourages clearer thinking about the process of habituation, such that the theory, design, and analysis are all in line with each other. The article concludes with concrete recommendations to improve current practices in infant habituation research.

Relations between parental metacognitive talk and children’s early metacognition and memory

After decades of research suggesting that metacognition—that is, processes whereby people monitor and regulate their cognitive performance—did not emerge and is not related to children’s performance until late childhood, recent studies have provided evidence that even preverbal infants can access their internal states. The existence of this basic metacognition raises the question of the variables influencing its development at such a young age and whether such early skills could predict successful cognitive performance. The current study had two main goals: (a) exploring the relation between parental metacognitive style and children’s early metacognition and (b) determining whether these early metacognitive skills can predict children’s memory performance. To this end, 2.5- to 4.5-year-old children (N = 72) and their parents were recruited. To assess parental metacognitive style, parent–child dyads were invited to participate in a 15-min session during which they played memory games. The parents’ speech during this session was later coded for metacognitive content. Children’s memory was assessed using cued recall and recognition tests. During one of these recognition tests, participants had the opportunity to ask for a cue to help them decide whether their response was correct (i.e., metacognitive measure). Results revealed that parental metacognitive style predicted both children’s metacognitive accuracy and memory performance. Interestingly, a mediation effect of children’s metacognitive skills on the relation between parental style and memory performance was found. These findings suggest that environmental factors such as parental metacognitive style are related to children’s early metacognition, which in turn is linked to children’s memory development.

Preverbal infants’ reactions to third-party punishments and rewards delivered toward fair and unfair agents

Rewarding individuals who distribute resources fairly and punishing those who distribute resources unfairly may be very important actions for fostering cooperation. This study investigated whether 9-month-olds have some expectations concerning punishments and rewards that follow distributive actions. Infants were shown simple animations and were tested using the violation-of-expectation paradigm. In Experiment 1, we found that infants looked longer when they saw a bystander delivering a corporal punishment to a ‘fair distributor,' who distributed some windfall resources equally to the possible recipients, rather than to an ‘unfair distributor,' who distributed the resources unequally. This pattern of looking times was reversed when, in Experiment 2, punishments were replaced with rewards. These findings suggest an early emergence of expectations about punishing and rewarding actions in third-party contexts, and they help to evaluate competing claims about the origins of a sense of fairness.

Infants expect agents to minimize the collective cost of collaborative actions

This paper argues that human infants address the challenges of optimizing, recognizing, and interpreting collaborative behaviors by assessing their collective efficiency. This hypothesis was tested by using a looking-time study. Fourteen-month-olds (N = 32) were familiarized with agents performing a collaborative action in computer animations. During the test phase, the looking times were measured while the agents acted with various efficiency parameters. In the critical condition, the agents’ actions were individually efficient, but their combination was either collectively efficient or inefficient. Infants looked longer at test events that violated expectations of collective efficiency (p = .006, d = 0.79). Thus, preverbal infants apply expectations of collective efficiency to actions involving multiple agents.

Preverbal infants tune manual choices on subliminal affective information

Human behaviour is often shaped by unconscious emotional cues. From early on, infants are able to process emotional signals even if presented subliminally; however, whether subliminal emotional expressions are capable to affect infants’ behaviour remains unknown. The current study aimed to fill this gap, recording 8–10-month-old infants’ looking time and manual choice toward two objects previously associated to subliminal emotional faces. Results demonstrated that infants’ manual choice, but not looking time, was guided by the previously presented subliminal emotional signal, as infants preferred to choose the object associated to the happy face. Overall, our findings show that preverbal infants tune their behaviour based on affective information, which drives them towards or away from previous encounters, even outside conscious awareness.

Infants' anticipatory eye movements: feature-based attention guides infants' visual attention.

When looking for an object, we identify it by selectively focusing our attention to a specific feature, known as feature-based attention. This basic attentional system has been reported in young children; however, little is known of whether infants could use feature-based attention. We have introduced a newly developed anticipation-looking task, where infants learned to direct their attention endogenously to a specific feature based on the learned feature (color or orientation), in 60 preverbal infants aged 7-8months. We found that preverbal infants aged 7-8months can direct their attention endogenously to the specific target feature among irrelevant features, thus showing the feature-based attentional selection. Experiment 2 bolstered this finding by demonstrating that infants directed their attention depending on the familiarized feature that belongs to a never-experienced object. These results that infants can form anticipation by color and orientation reflect they could drive their attention through feature-based selection.

Tracking transitional probabilities and segmenting auditory sequences are dissociable processes in adults and neonates.

Since speech is a continuous stream with no systematic boundaries between words, how do pre-verbal infants manage to discover words? A proposed solution is that they might use the transitional probability between adjacent syllables, which drops at word boundaries. Here, we tested the limits of this mechanism by increasing the size of the word-unit to four syllables, and its automaticity by testing asleep neonates. Using markers of statistical learning in neonates' EEG, compared to adult behavioral performances in the same task, we confirmed that statistical learning is automatic enough to be efficient even in sleeping neonates. We also revealed that: (1) Successfully tracking transition probabilities (TP) in a sequence is not sufficient to segment it. (2) Prosodic cues, as subtle as subliminal pauses, enable to recover words segmenting capacities. (3) Adults' and neonates' capacities to segment streams seem remarkably similar despite the difference of maturation and expertise. Finally, we observed that learning increased the overall similarity of neural responses across infants during exposure to the stream, providing a novel neural marker to monitor learning. Thus, from birth, infants are equipped with adult-like tools, allowing them to extract small coherent word-like units from auditory streams, based on the combination of statistical analyses and auditory parsing cues. RESEARCH HIGHLIGHTS: Successfully tracking transitional probabilities in a sequence is not always sufficient to segment it. Word segmentation solely based on transitional probability is limited to bi- or tri-syllabic elements. Prosodic cues, as subtle as subliminal pauses, enable to recover chunking capacities in sleeping neonates and awake adults for quadriplets.

Cross-cultural differences in early expectations about third party resource distribution

Research using non-verbal looking-time methods suggests that pre-verbal infants are able to detect inequality in third party resource allocations. However, nothing is known about the emergence of this capacity outside a very narrow Western context. We compared 12- to 20-month-old infants (N = 54) from one Western and two non-Western societies. Swedish infants confirmed the pattern from previous Western samples by looking longer at the unequal distribution, suggesting that they expected the resources to be distributed equally. Samburu infants looked longer at the equal distribution, suggesting an expectation of unequal distribution. The Kikuyu infants looked equally at both distributions, and did not show any specific exactions. These results suggest that expectations of equal distributions in third party allocations are affected by experience of cultural variations of distributive norms and social interaction early in development.

Great expectations: The construct validity of the violation‐of‐expectation method for studying infant cognition

AbstractThe violation‐of‐expectation method has been used in thousands of studies examining the breadth and depth of preverbal infants' knowledge and cognitive capacities. In this commentary, we review evidence that supports the violation‐of‐expectation method as an important tool for infant research that has strong construct validity. We show that this method reveals infants' expectations, produces reliable results across study designs and stimuli, and is grounded in theories of learning. We support and encourage the use of this method to continue to unveil the scope and sophistication of infant cognition.

Third-party punishment by preverbal infants

Third-party punishment of antisocial others is unique to humans and seems to be universal across cultures. However, its emergence in ontogeny remains unknown. We developed a participatory cognitive paradigm using gaze-contingency techniques, in which infants can use their gaze to affect agents displayed on a monitor. In this paradigm, fixation on an agent triggers the event of a stone crushing the agent. Throughout five experiments (total N = 120), we show that eight-month-old infants punished antisocial others. Specifically, infants increased their selective looks at the aggressor after watching aggressive interactions. Additionally, three control experiments excluded alternative interpretations of their selective gaze, suggesting that punishment-related decision-making influenced looking behaviour. These findings indicate that a disposition for third-party punishment of antisocial others emerges in early infancy and emphasize the importance of third-party punishment for human cooperation. This behavioural tendency may be a human trait acquired over the course of evolution.

In Bilinguals' Hands: Identification of Bilingual, Preverbal Infants at Risk for Language Delay.

Studies with monolingual infants show that the gestural behavior of 1–2-year-olds is a strong predictor for later language competencies and, more specifically, that the absence of index-finger pointing at 12 months seems to be a valid indicator for risk of language delay (LD). In this study a lack of index-finger pointing at 12 months was utilized as diagnostic criterion to identity infants with a high risk for LD at 24 months in a sample of 42 infants growing up bilingually. Results confirm earlier findings from monolinguals showing that 12-month-olds who point with the extended index finger have an advanced language status at 24 months and are less likely language delayed than infants who only point with the whole hand and do not produce index-finger points at 12 months.