Understanding Cognitive Development

Approaches from Mind and Brain

Barbara Landau

• Publisher: Psychology Press
• Year: 2016
• ISBN:
  9781134933969
• Edition: 1
• Topic: Psicologia
• Subtopic: Storia e teoria della psicologia

The papers in this volume examine the state of the art in key areas of developmental cognitive neuroscience, focusing on theoretically driven research on cognition and its development. The past decade has seen an increasing number of empirical papers on the relationship between brain and cognitive development. But despite the clearly burgeoning interest in this topic, there is a relative paucity of work motivated by deep theoretical questions about the nature of cognition and its development. Many papers are still in the mode of reporting brain-cognition correlations with a focus on regional activations during brain imaging - a useful approach, but one that is limited with respect to its contributions to understanding the structure of cognition and its development. The papers in this special issue of Cognitive Neuropsychology consider a number of domains and mechanisms in cognition, including language, number, space, faces, reading, memory, and attention, and represent the wealth of approaches and techniques that can be used to shed light on the nature of cognitive development in brain and mind. These include cross-species comparisons, studies of development under experiential deprivation or genetic differences, classical developmental experimentation, and imaging techniques such as NIRS and fMRI which have recently been applied to developmental questions. The combination of solid theorizing together with a broad range of approaches allows a critical but constructive look at the latest findings in the field relevant to answering enduring questions about cognition, its development, and its realization in the developing brain.

Introduction

Understanding cognitive development: Approaches from mind and brain

Barbara Landau
Department of Cognitive Science, Johns Hopkins University, Baltimore, MD, USA

The concept for this special issue emerged in the summer of 2010, when a small group of cognitive scientists—including some authors of papers in this volume—assembled for an informal thought session regarding the status of research on cognitive development in the context of the explosive growth in the field of cognitive neuroscience. As is well known, the past few decades have seen enormous growth in the brain sciences, and intense attention to questions of how we understand characteristics of the mind as embodied in a physical system, the brain. Moreover, the past decade has witnessed particular growth in the field of developmental cognitive neuroscience, with increasing numbers of empirical papers and specialized volumes published, driven not only by improvements and availability of new methods appropriate to infants and children, but also by the recognition that if we are to understand cognitive function and how it is carried out by the brain, we will have to understand how both mind and brain develop—how they change over the lifetime.

Given the recent explosive growth in the new field of developmental cognitive neuroscience and concomitant increase in empirical papers, edited volumes, and new journals, why assemble another set of articles?

The reason is the strong sense from at least some of us that development of mind has been left out of the mind–brain equation. Although we have increasing knowledge of brain structure and its change from infancy through adulthood, accumulating data on the regional activations typical for different tasks and domains, and evidence on the nature of changes in connectivity over development, we have made little progress in understanding how cognition is embodied in the brain. Part of the reason for this is that relatively little progress has been made in connecting levels of explanation; e.g., discovering computational schemes that can help us understand how neural tissue accomplishes cognitive functions. Another reason is that rapid improvements in brain imaging techniques have made it more and more straightforward to carry out studies in which we can see the brain in action, as we carry out cognitive tasks; and this has invited ever more research examining the "brain" end of the equation. The question remains, however, as to how cognitive function—instantiated either by an entire task or its subparts—maps onto the action of individual neurons, groups of neurons, and networks of neurons across different regions of the brain. In short, although the past decade has seen an increasing number of empirical papers on the relationship between brain and cognitive development, there is a relative paucity of work motivated by deep theoretical questions about the nature of cognition and its development. Many papers are still in the mode of reporting brain–cognition correlations with a focus on regional activations during brain imaging—a useful approach, but one that is limited with respect to its contributions to understanding the structure of cognition and its development.

The special issue of Cognitive Neuropsychology was conceptualized as a response to this problem, and accordingly, the authors of papers in the issue were invited to submit a paper using the following guidelines. Authors were advised that their papers would principally and most crucially be required to focus on theoretical questions important to the study of cognition and its development—that is, the mind end of the equation. In particular, authors were invited to contribute a "position paper" in which they would explore a theoretically important question or set of questions about cognitive development in mind and brain, using any approaches and methods they saw fit. These approaches and methods turned out to be quite varied, including experimental studies of human behavior, brain imaging using near-infrared spectroscopy (NIRS) and functional magnetic resonance imaging (fMRI), cross-species comparisons that include neurophysiology, behavior, and outcomes under conditions of controlled rearing, linguistic theory and the broad methods of psycholinguistics, and studies of cognitive structure comparing normally developing individuals with those who have learning differences, genetic differences, or substantial differences in sensory experience due to deafness or blindness.

The result is a collection of nine papers that embrace a range of theoretical and empirical approaches, and address important questions about cognition in a range of empirical domains, including basic visual and auditory perception, face recognition, number, space, working memory, and language (spoken, signed, written). The wide range of approaches reminds us that we now have within our scientific repertoire a marvellously broad range of tools that can be used to understand the development of cognition in mind and brain.

The broad reach of the papers spans a number of themes that are threaded throughout the volume. The first is the theoretical imperative: All authors motivate their papers by posing key theoretical questions about cognition. The second is methodological scrutiny. The authors offer both cautionary tales about methodology and design and refreshing perspectives that remind us of how sometimes small differences in method can result in quite different experimental outcomes (see, e.g., Aslin, 2012 this issue; Ramus & Abissar, 2012 this issue; Hirshorn, Fernandez, & Bavelier, 2012 this issue; McKone, Crookes, Jeffrey, & Dilks, 2012 this issue). The third theme is the breadth of approaches relevant to questions of human cognition and its development in mind and brain. As noted above, the approaches offered in the volume range from cross-species comparisons (e.g., Bonn & Cantlon, 2012 this issue; Vallortigara, 2012 this issue) and controlled rearing studies in nonhuman species (Vallortigara, 2012 this issue) to brain imaging (Aslin, 2012 this issue; Poeppel, 2012 this issue; Bedny & Saxe, 2012 this issue; McKone et al., 2012 this issue) and work with deficit populations such as the congenitally blind (Bedny & Saxe, 2012 this issue) or deaf (Hirshorn, Fernandez, & Bavelier, 2012 this issue), people who are dyslexic (Ramus & Ahissar, 2012 this issue) and people with Williams syndrome (Musolino & Landau, 2012 this issue). The fourth theme is the importance of development in understanding both how the brain works and how it realizes cognitive function. Studies of deficit populations inform us about the plasticity of the brain (Bedny & Saxe, 2012 this issue), which cognitive functions are most robust and likely to be privileged, "core", or innate (Bedny & Saxe, 2012 this issue; Bonn & Cantlon, 2012 this issue; McKone et al., 2012 this issue Musolino & Landau, 2012 this issue), and which functions are susceptible to differences in experience (Hirshorn et al., 2012 this issue). Indeed, a number of authors point out that the most fundamental properties of human cognitive systems—the innate "parts list" in Poeppel's terms—can be best discovered by studying the organism as it develops, placing developmental studies at the forefront of inquiry in terms of importance.

The papers are organized into three sections. The first section is Issues of Theory and Method, containing papers by Aslin and Poeppel. These opening papers help us to situate studies of mind–brain relationships over development in the context of both the excitement of new methodologies and the challenges inherent in connecting these methods and their results to theories of cognition. Aslin (2012 this issue) focuses on the new tool of NIRS to study infant cognition, broadly reviewing the literature and raising important issues about potential pitfalls of experimental designs that have been used, the need for hypothesis-driven work, and questions about the kinds of inferences we have made and that we can make from NIRS results, given inherent limitations in the method. In the end, Aslin suggests that we may have so far attempted to ask questions about infant cognition that are simply too complex for our current understanding of what NIRS can tell us; and he encourages the field to first map out some of the most basic perceptual functions in order to provide a strong foundation for attacking more complex cognitive functions. Poeppel (2012 this issue), too, challenges us to think hard about what we can learn about cognition from existing methods about properties of the brain and mind. He discusses two problems. One is the "practical" maps problem, for which he emphasizes that although localization and spatial activation are by far the most common kind of empirical result in the field, still, "uncontroversially, localization and spatial mapping are not explanation". The question, then, is whether—given ever-increasing technical sophistication—the approach of regional mapping will ever satisfy the explanatory needs for understanding how the functions of perception and cognition are carried out. The second problem he discusses is the "principled" mapping problem—how to formulate the correspondences and, ultimately, the causal links between the "parts list" for cognition (e.g., syllable, morpheme, noun phrase) and the parts list of neurobiology (e.g., neurons, synapses, long-term potentiation). Ultimately, Poeppel challenges all of us—across the cognitive sciences and neurosciences—to reformulate our thinking, by making a powerful but undoubtedly controversial argument that the cognitive sciences (dealing as they do with the functional units of cognition) provide the elements (representations) and computations that neuroscientists should then seek to identify at the neural (implementational) level.

Section 2, Atypical Experience and Genetic Differences, focuses on how unusual cases of human development can shed light on the nature of cognitive structure. Bedny and Saxe (2012 this issue) lead the section, presenting compelling studies of cognition in the congenitally blind, using data from behavioural and brain-imaging studies to explore how lifelong absence of visual experience affects cognitive structure and function. They begin by discussing now extensive evidence showing that primary visual cortex in congenitally blind people can take on other sensory/perceptual functions (e.g., spatial functions underlying the perception of Braille) as well as high-level functions involved in language. Given this significant evidence for the plasticity of the human brain in its basic organization, and its dependence on particular types of sensory experience (i.e., vision), the authors then ask whether the same plasticity effects extend to higher-level functions such as concepts. They argue that, contrary to classical empiricist hypotheses about the role of sensory experience in the development of cognition, blind and sighted individuals possess much the same conceptual structure for lexical concepts; moreover, these structures are housed in virtually identical areas of the brain for the blind and sighted. This, together with the compelling evidence for plasticity in sensory and perceptual representations, makes a beautiful case for understanding both what aspects of brain and mind remain the same under changes in sensory and perceptual input, and what aspects are subject to change.

Hirshorn, Fernandez, and Bavelier (2012 this issue) make an equally compelling point in their paper, illustrating that the way that one theoretically conceptualizes a cognitive difference between populations can have profound effects on how these differences are tested, and the conclusions that one draws. They start with a wellknown and persistent finding showing consistent differences between deaf signers and hearing speakers in short-term memory (STM) tasks, with deaf signers regularly underperforming hearing speakers. This has most often been interpreted as a deficit in temporal order processing that stems from differences in experience. Hirshorn and colleagues show that deaf signers' performance in such tasks depends not on differences in the ability to process temporal order, but rather on the different biases that hearing/deaf speakers develop regarding the kinds of cues they use to carry out the task. In showing this, they provide evidence for a very different kind of theoretical explanation underlying the difference shown between groups, emphasizing the role that different language modalities afford (rather than available perceptual systems per se), with speech and sign experience leading to different biases in the kinds of coding that are most likely in many STM tasks. Their studies also illustrate how conclusions about the effects of different kinds of experience must undergo rigorous examination with respect to alternative hypotheses.

Ramus and Ahissar (2012 this issue) address theoretical problems in understanding the root causes of dyslexia. They note that this disorder has invited a proliferation of theories and that conflicting patterns of data abound, despite decades of systematic work and more than a century of clinical observation. Most crucially, however, they argue that the field has tended to focus too much on poor performance by dyslexics, and not enough on strong performance by dyslexics, leading to theories that explain only half of the overall profile—which results in no explanation at all. Ramus and Ahissar argue that the key to understanding dyslexia (as well as other disorders, such as autism and amusia) is to carry out careful and systematic task analyses of both tasks that elicit poor performance and those that elicit strong performance. For example, they note that tasks involving phonology typically elicit poor performance among dyslexics; however, tasks that are used often engage a wide range of cognitive processes such as mental manipulations of speech sounds, strong working memory, rapid responses, or metalinguistic judgements. The same complexities hold for tasks examining the visual system's potential contribution to dyslexia. Ramus and Ahissar end by encouraging the field to focus on much deeper and more systematic task analyses—understanding the basic cognitive representations and processes that are required in order to carry out a task. They also encourage scientists to round out the task battery in order to document both strengths and weaknesses, and to consider examining quite basic perceptual functions before moving on to cognitive functions that are undeniably complex. Little of this has been done, in the authors' view, but much more will be needed in order to construct accurate theories of the underlying deficit or deficits.

Musolino and Landau (2012 this issue) then take up the case of Williams syndrome, a genetic syndrome in which roughly 25 genes are missing, giving rise to an unusual cognitive profile in which people show strong linguistic abilities but severe spatial impairment. The authors use this syndrome to explore how one could address one of cognitive science's holy grails—the possibility of unravelling the causal chains between genes and cognition—and focus their attention on thinking about the kind of theory that might be able to account for the language profile. They argue that to do this, we need to have a theory at the appropriate level of complexity and power to explain what is to be acquired—this turns out to be available in the form of linguistic theory. This theory offers the opportunity to develop test cases to ask whether people with Williams syndrome possess knowledge of complex aspects of linguistic structure. Musolino and Landau present positive evidence on this question. They then contrast this linguistic theory-driven approach with the neuroconstructivist approach to language learning, which has been offered to support the idea that language in people with Williams syndrome is not structurally intact, but rather is qualitatively different from normal individuals. By comparing the two approaches' power to explain the data, Musolino and Landau show that the two are in fact not commensurate in what they can explain, and therefore simply do not compete equally in advancing our understanding of what is learned and how this is accomplished. By emphasizing the role of theory in understanding cognition and its development, Musolino and Landau challenge us to become more precise in the theories we use to explain both normal and unusual development.

The third section, Integrative Approaches to Specific Cognitive Domains includes papers that focus on number (Bonn & Cantlon), face processing (McKone et al.), and "core" knowledge including objects and space (Vallortigara), all of which are foundational to cognition in humans as well as other species. Bonn and Cantlon (2012 this issue) lead the section by reviewing data from human behaviour in infancy, childhood, and adulthood, as well as brain imaging in humans and behaviour and neurophysiology in other species. They examine the fundamental neural and cognitive relations among different quantitative dimensions (e.g., number, size, pitch, loudness, brightness), exploring how these relationships could have evolved over time, and how they might be realized over human development. They argue that the fundamental conceptual domain of number unifies many different phenomena, using theory and evidence from a wide range of sources—empirical studies of humans (of different ages, patients and intact individuals) and other species, both brain-based and behavioural. Bonn and Cantlon show us the power of drawing on such wide-ranging sources of evidence, enriching our understanding of the most fundamental aspects of human cognition and their development.

McKone et al. (2012 this issue) then provide a quite comprehensive review of the literature on face representation in development, focusing on the evaluation of the classical hypothesis for face identification that has proposed an extremely protracted developmental timetable, with maturity arriving only in adolescence. Contrary to this idea, McKone et al. present compelling evidence that all qualitative indicators of key phen...

Table of contents

• Cover
• Title
• Copyright
• Contents
• Citation Information
• 1. Introduction. Understanding cognitive development: Approaches from mind and brain
• Part I: Issues of Theory and Method
• Part II: Atypical experience and genetic differences
• Part III: Integrative approaches to specific cognitive domains
• Index