Experience-dependent brain development as a key to understanding the language system

An influential view of the nature of the language system is that of an evolved biological system in which a set of rules is combined with a lexicon that contains the words of the language together with a representation of their context. Alternative views, usually based on connectionist modeling, attempt to explain the structure of language on the basis of complex associative processes. Here I put forward a third view that stresses experience-dependent structural development of the brain circuits supporting language as a core principle of the organization of the language system. On this view, embodied in a recent neuroconstructivist neural network of past tense development and processing, initial domain-general predispositions enable the development of functionally specialized brain structures through interactions between experience-dependent brain development and statistical learning in a structured environment. Together, these processes shape a biological adult language system that appears to separate into distinct mechanism for processing rules and exceptions, whereas in reality those subsystems co-develop and interact closely. This view puts experience-dependent brain development in response to a specific language environment at the heart of understanding not only language development but adult language processing as well

Constructivist neural network models of cognitive development

In this thesis I investigate the modelling of cognitive development with constructivist neural networks. I argue that the constructivist nature of development, that is, the building of a cognitive system through active interactions with its environment, is an essential property of human development and should be considered in models of cognitive development. I evaluate this claim on the basis of evidence from cortical development, cognitive development, and learning theory. In an empirical evaluation of this claim, I then present a constructivist neural network model of the acquisition of the English past tense and of impaired inflectional processing in German agrammatic aphasics. The model displays a realistic course of acquisition, closely modelling the U-shaped learning curve and more detailed effects such as frequency and family effects. Further, the model develops double dissociations between regular and irregular verbs. I argue that the ability of the model to account for the hu..

Predictive processing and developmental language disorder

Purpose: Research in the cognitive and neural sciences has situated predictive processing – the anticipation of upcoming percepts – as a dominant function of the brain. The purpose of this article is to argue that prediction should feature more prominently in explanatory accounts of sentence processing and comprehension deficits in developmental language disorder (DLD). Method: We evaluate behavioural and neurophysiological data relevant to the theme of prediction in early typical and atypical language acquisition and processing. Results: Poor syntactic awareness – attributable in part to an underlying statistical learning deficit – is likely to impede syntax-based predictive processing in children with DLD, conferring deficits in spoken sentence comprehension. Furthermore, there may be a feedback cycle in which poor syntactic awareness impedes children’s ability to anticipate upcoming percepts, and this in turn makes children unable to improve their syntactic awareness on the basis of prediction error signals. Conclusion: This article offers a re-focusing of theory on sentence processing and comprehension deficits in DLD, from a difficulty in processing and integrating perceived syntactic features, to a difficulty in anticipating what is coming next

Pupillometry in infancy research

The human pupil is a small opening in each eye that dilates in response not only to changes in luminance but also to novel events. This makes changes in pupil diameter an attractive measure in studies on infants’ and young children’s physical and social cognition. However, designing and interpreting pupillometry studies for developmental populations comes with its own caveats. Here we give an overview of how psychologically induced changes in pupil diameter have been investigated and interpreted in developmental studies. We highlight the methodological challenges when designing experiments for infants and young children and provide several suggestions to address common problems. The fact that pupillometry provides a sensitive measure of the time course of responses to novelty extends the scope of possibilities for researchers studying infant cognition and development

A learned label modulates object representations in 10-month-old infants

Despite substantial evidence for a bidirectional relationship between language and representation, the roots of this relationship in infancy are not known. The current study explores the possibility that labels may affect object representations at the earliest stages of language acquisition. We asked parents to play with their 10-month-old infants with two novel toys for three minutes, every day for a week, teaching infants a novel word for one toy but not the other. After a week infants participated in a familiarization task in which they saw each object for 8 trials in silence, followed by a test trial consisting of both objects accompanied by the trained word. Infants exhibited a faster decline in looking times to the previously unlabeled object. These data speak to the current debate over the status of labels in human cognition, supporting accounts in which labels are an integral part of representation

Curiosity Enhances Incidental Object Encoding

Recent research with adults indicates that curiosity induced by uncertainty enhances learning and memory outcomes and that the resolution of curiosity has a special role in curiosity-driven learning. However, the role of curiosity-based learning in early development is unclear. Here we presented 8-month-old infants with a novel looking time procedure to explore (a) whether uncertainty-induced curiosity enhances learning of incidental information and (b) whether uncertainty-induced curiosity leads infants to seek uncertainty resolution over novelty. In Experiment 1, infants saw blurred images to induce curiosity (Curiosity sequence) or a clear image (Non-curiosity sequence) followed by presentation of incidental objects. Despite looking equally to the incidental objects in both sequences, in a subsequent object recognition phase infants looked longer to incidental objects presented in the Non-curiosity condition compared with the Curiosity condition, indicating that curiosity induced by blurred pictures enhanced the processing of the incidental object, leading to a novelty preference for the incidental object shown in the Non-Curiosity condition. In Experiment 2, a blurred picture of a novel toy was first presented, followed by its corresponding clear picture paired with a clear picture of a new novel toy side by side. Infants showed no preference for either image, providing no evidence for a drive to resolve uncertainty. Overall, the current experiments suggest that curiosity has a broad attention-enhancing effect in infancy. Taking into account existing studies with older children and adults, we propose a developmental change in the function of curiosity, from this attentional enhancement to more goal-directed information seeking in older children and adults

Precis of neuroconstructivism: how the brain constructs cognition

Neuroconstructivism: How the Brain Constructs Cognition proposes a unifying framework for the study of cognitive development that brings together (1) constructivism (which views development as the progressive elaboration of increasingly complex structures), (2) cognitive neuroscience (which aims to understand the neural mechanisms underlying behavior), and (3) computational modeling (which proposes formal and explicit specifications of information processing). The guiding principle of our approach is context dependence, within and (in contrast to Marr [1982]) between levels of organization. We propose that three mechanisms guide the emergence of representations: competition, cooperation, and chronotopy; which themselves allow for two central processes: proactivity and progressive specialization. We suggest that the main outcome of development is partial representations, distributed across distinct functional circuits. This framework is derived by examining development at the level of single neurons, brain systems, and whole organisms. We use the terms encellment, embrainment, and embodiment to describe the higher-level contextual influences that act at each of these levels of organization. To illustrate these mechanisms in operation we provide case studies in early visual perception, infant habituation, phonological development, and object representations in infancy. Three further case studies are concerned with interactions between levels of explanation: social development, atypical development and within that, developmental dyslexia. We conclude that cognitive development arises from a dynamic, contextual change in embodied neural structures leading to partial representations across multiple brain regions and timescales, in response to proactively specified physical and social environment