The precision of 12-month-old infants' link between language and categorization predicts vocabulary size at 12 and 18 months

The Cognitive Architecture of Infant Attachment

Meta-analytic evidence indicates that the quality of the attachment relationship that infants establish with their primary caregiver has enduring significance for socioemotional and cognitive outcomes. However, the mechanisms by which early attachment experiences contribute to subsequent development remain underspecified. According to attachment theory, early attachment experiences become embodied in the form of cognitive-affective representations, referred to as internal working models (IWMs), that guide future behavior. Little is known, however, about the cognitive architecture of IWMs in infancy. In this article, we discuss significant advances made in the field of infant cognitive development and propose that leveraging insights from this research has the potential to fundamentally shape our understanding of the cognitive architecture of attachment representations in infancy. We also propose that the integration of attachment research into cognitive research can shed light on the role of early experiences, individual differences, and stability and change in infant cognition, as well as open new routes of investigation in cognitive studies, which will further our understanding of human knowledge. We provide recommendations for future research throughout the article and conclude by using our collaborative research as an example.

Neurobiological mechanisms for language, symbols and concepts: Clues from brain-constrained deep neural networks

Neural networks are successfully used to imitate and model cognitive processes. However, to provide clues about the neurobiological mechanisms enabling human cognition, these models need to mimic the structure and function of real brains. Brain-constrained networks differ from classic neural networks by implementing brain similarities at different scales, ranging from the micro- and mesoscopic levels of neuronal function, local neuronal links and circuit interaction to large-scale anatomical structure and between-area connectivity. This review shows how brain-constrained neural networks can be applied to study in silico the formation of mechanisms for symbol and concept processing and to work towards neurobiological explanations of specifically human cognitive abilities. These include verbal working memory and learning of large vocabularies of symbols, semantic binding carried by specific areas of cortex, attention focusing and modulation driven by symbol type, and the acquisition of concrete and abstract concepts partly influenced by symbols. Neuronal assembly activity in the networks is analyzed to deliver putative mechanistic correlates of higher cognitive processes and to develop candidate explanations founded in established neurobiological principles.

A principled link between object naming and representation is available to infants by seven months of age

By their first birthdays, infants represent objects flexibly as a function of not only whether but how the objects are named. Applying the same name to a set of different objects from the same category supports object categorization, with infants encoding commonalities among objects at the expense of individuating details. In contrast, applying a distinct name to each object supports individuation, with infants encoding distinct features at the expense of categorical information. Here, we consider the development of this nuanced link between naming and representation in infants' first year. Infants at 12 months (Study 1; N = 55) and 7 months (Study 2; N = 96) participated in an online recognition memory task. All infants saw the same objects, but their recognition of these objects at test varied as a function of how they had been named. At both ages, infants successfully recognized objects that had been named with distinct labels but failed to recognize these objects when they had all been named with the same, consistent label. This new evidence demonstrates that a principled link between object naming and representation is available by 7 months, early enough to support infants as they begin mapping words to meaning.

Preserved category-based inferences for word learning in school-aged children with developmental language disorder

Word learning difficulties are often found in children with Developmental Language Disorder (DLD). Lexical patterns of difficulties appear to be well described in the context of DLD but very little research focuses on their underlying causes. Word learning is known to be an inference-based process, constrained by categorization, which helps the extension of new words to unfamiliar referents and situations. These processes appear integrated in Bayesian models of cognition, which supposes that learning relies on an inductive inference process that recruits prior knowledge and principles of statistical learning (detection of regularities). Taken together, these mechanisms remain underexplored in DLD. Our study aims to define whether children with DLD can draw inductive inferences in a word learning context using categorization. Twenty children with DLD (between 6;0 and 12;6), and 20 language-matched and 16 age-matched controls were exposed to a word learning task where they were given exemplars of objects associated with pseudo-words. The objects belonged to six categories spread across three hierarchical levels. For each item, the children chose which one(s), among a set of test objects from the same categories, could be labelled the same way (word extension). Results showed that school-aged children with DLD could extend new words to broader categories as well as their typically developing (TD) peers. Nevertheless, none of the DLD or TD children showed a specification of their categorization of familiar instances that referred to more restricted instances. Our study suggests preserved abilities in using conceptual knowledge in order to learn new words, which could be used as a compensative strategy in the context of therapy. Further studies are needed to investigate this ability in more complex learning contexts.

Naming guides how 12-month-old infants encode and remember objects

A foundation of human cognition is the flexibility with which we can represent any object as either a unique individual (my dog Fred) or a member of an object category (dog, animal). This conceptual flexibility is supported by language; the way we name an object is instrumental to our construal of that object as an individual or a category member. Evidence from a new recognition memory task reveals that infants are sensitive to this principled link between naming and object representation by age 12 mo. During training, all infants (n = 77) viewed four distinct objects from the same object category, each introduced in conjunction with either the same novel noun (Consistent Name condition), a distinct novel noun for each object (Distinct Names condition), or the same sine-wave tone sequence (Consistent Tone condition). At test, infants saw each training object again, presented in silence along with a new object from the same category. Infants in the Consistent Name condition showed poor recognition memory at test, suggesting that consistently applied names focused them primarily on commonalities among the named objects at the expense of distinctions among them. Infants in the Distinct Names condition recognized three of the four objects, suggesting that applying distinct names enhanced infants' encoding of the distinctions among the objects. Infants in the control Consistent Tone condition recognized only the object they had most recently seen. Thus, even for infants just beginning to speak their first words, the way in which an object is named guides infants' encoding, representation, and memory for that object.

Becoming human: human infants link language and cognition, but what about the other great apes?

Human language has no parallel elsewhere in the animal kingdom. It is unique not only for its structural complexity but also for its inextricable interface with core cognitive capacities such as object representation, object categorization and abstract rule learning. Here, we (i) review recent evidence documenting how (and how early) language interacts with these core cognitive capacities in the mind of the human infant, and (ii) consider whether this link exists in non-human great apes-our closest genealogical cousins. Research with human infants demonstrates that well before they begin to speak, infants have already forged a link between language and core cognitive capacities. Evident by just three months of age, this language-cognition link unfolds in a rich developmental cascade, with each advance providing the foundation for subsequent, more precise and more powerful links. This link supports our species' capacity to represent and convey abstract concepts and to communicate beyond the immediate here and now. By contrast, although the communication systems of great apes are sophisticated in their own right, there is no conclusive evidence that apes establish reference, convey information declaratively or pass down communicative devices via cultural transmission. Thus, the evidence currently available reinforces the uniqueness of human language and the power of its interface to cognition. This article is part of the theme issue 'What can animal communication teach us about human language?'

Maturation constrains the effect of exposure in linking language and thought: evidence from healthy preterm infants

The power of human language rests upon its intricate links to human cognition. By 3 months of age, listening to language supports infants' ability to form object categories, a building block of cognition. Moreover, infants display a systematic shift between 3 and 4 months - a shift from familiarity to novelty preferences - in their expression of this link between language and core cognitive processes. Here, we capitalize on this tightly-timed developmental shift in fullterm infants to assess (a) whether it also appears in preterm infants and (b) whether it reflects infants' maturational status or the duration of their postnatal experience. Healthy late preterm infants (N = 22) participated in an object categorization task while listening to language. Their performance, coupled with that of fullterm infants, reveals that this developmental shift is evident in preterm infants and unfolds on the same maturational timetable as in their fullterm counterparts.

Linking Language and Cognition in Infancy

Human language, a signature of our species, derives its power from its links to human cognition. For centuries, scholars have been captivated by this link between language and cognition. In this article, we shift this focus. Adopting a developmental lens, we review recent evidence that sheds light on the origin and developmental unfolding of the link between language and cognition in the first year of life. This evidence, which reveals the joint contributions of infants' innate capacities and their sensitivity to experience, highlights how a precocious link between language and cognition advances infants beyond their initial perceptual and conceptual capacities. The evidence also identifies the conceptual advantages this link brings to human infants. By tracing the emergence of a language-cognition link in infancy, this article reveals a dynamic developmental cascade in infants' first year, with each developmental advance providing a foundation for subsequent advances.

Linking language and categorization in infancy

Language exerts a powerful influence on our concepts. We review evidence documenting the developmental origins of a precocious link between language and object categories in very young infants. This collection of studies documents a cascading process in which early links between language and cognition provide the foundation for later, more precise ones. We propose that, early in life, language promotes categorization at least in part through its status as a social, communicative signal. But over the first year, infants home in on the referential power of language and, by their second year, begin teasing apart distinct kinds of names (e.g. nouns, adjectives) and their relation to distinct kinds of concepts (e.g. object categories, properties). To complement this proposal, we also relate this evidence to several alternative accounts of language's effect on categorization, appealing to similarity ('labels-as-features'), familiarity ('auditory overshadowing'), and communicative biases ('natural pedagogy').

Early development of abstract language knowledge: evidence from perception-production transfer of birth-language memory

Children adopted early in life into another linguistic community typically forget their birth language but retain, unaware, relevant linguistic knowledge that may facilitate (re)learning of birth-language patterns. Understanding the nature of this knowledge can shed light on how language is acquired. Here, international adoptees from Korea with Dutch as their current language, and matched Dutch-native controls, provided speech production data on a Korean consonantal distinction unlike any Dutch distinctions, at the outset and end of an intensive perceptual training. The productions, elicited in a repetition task, were identified and rated by Korean listeners. Adoptees' production scores improved significantly more across the training period than control participants' scores, and, for adoptees only, relative production success correlated significantly with the rate of learning in perception (which had, as predicted, also surpassed that of the controls). Of the adoptee group, half had been adopted at 17 months or older (when talking would have begun), while half had been prelinguistic (under six months). The former group, with production experience, showed no advantage over the group without. Thus the adoptees' retained knowledge of Korean transferred from perception to production and appears to be abstract in nature rather than dependent on the amount of experience.

Naming influences 9-month-olds' identification of discrete categories along a perceptual continuum

A growing body of evidence documents that naming guides 9-month-old infants as they organize their visual experiences into categories. In particular, this evidence reveals that naming highlights categories when these are visually distinct. Here we advance this work in by introducing an anticipatory looking design to assess how naming influences infants' categorization of objects that vary along a perceptual continuum. We introduced 9-month-old infants (n = 48) to continua of novel creature-like objects. During the learning phase, infants had an opportunity to observe that objects from one end of the perceptual continuum moved to the left and objects from the other end moved to the right. What varied was how the objects were named. Infants in theone-name condition heard the same novel noun applied to all objects along the continuum; those in the two-name condition heard one name for objects from one end of the continuum and a second name for objects at the other end. At test, all infants viewed new objects from the same continuum. At issue was whether infants would anticipate the side to which the test objects would move and whether their expectations varied as a function of naming condition. Infants in the one-name condition formed a single overarching category and therefore searched for new test objects at either location; those in the two-name condition discerned two categories and therefore correctly anticipated the likely location of the test objects, whether these were close to the poles or to the center of the continuum. This provides the first evidence that by 9 months, naming supports both the number of categories infants impose along a perceptual continuum and the clarity of the category boundaries.