Young Children's Cognitive Development

Interrelationships Among Executive Functioning, Working Memory, Verbal Ability, and Theory of Mind

Wolfgang Schneider, Ruth Schumann-Hengsteler, Beate Sodian

• Publisher: Psychology Press
• Year: 2014
• eBook ISBN: 9781135614409
• Topic: Psychology
• Subtopic: Cognitive Psychology & Cognition
• Index: Psychology

A critical part of early childhood development is the development of "theory of mind" (ToM), which is the ability to take the perspective of another person. The main purpose of this book is to discuss and integrate findings from prominent research areas in developmental psychology that are typically studied in isolation, but are clearly related. Two examples are whether executive functions represent a precursor of ToM or whether ToM understanding predicts the development of executive functions, and to what extent children's level of verbal ability and their working memory are important predictors of performance on both executive functioning and ToM tasks. The chapters in this book give a detailed account of the major outcomes of this research. First, the state of the art concerning current understanding of the relevant constructs (working memory, ToM, executive functioning) and their developmental changes is presented, followed by chapters that deal with interactions among the core concepts. Its main focus is on theoretically important relationships among determinants of young children's cognitive development--considered to be "hot" issues in contemporary developmental psychology.

Based on presentations made at an international workshop, this book is divided into two parts. In the first part, five teams of researchers present theoretical analyses and overviews of empirical evidence regarding the core constructs of memory, executive functions, and ToM. The next part deals with the interplay among the core concepts outlined in Part I with developmental trends in the interaction.

Chapter 1

Introduction and Overview

Wolfgang Schneider

University of Würzburg

Ruth Schumann–Hengsteler

Catholic University of Eichstätt–Ingolstadt

Beate Sodian

University of München

The study of cognitive development has undergone considerable changes during the last three decades. In the 1970s, the field was dominated by information processing views that assumed parallel and closely interrelated developmental changes in different cognitive domains, thus emphasizing a domain-general perspective of cognitive development. This perspective changed during the course of the 1980s and 1990s as the importance of domain-specific processes was confirmed in numerous studies, reflected in different developmental patterns in foundational domains (Wellman & Gelman, 1998). Research on children’s developing understanding of the mental domain has become paradigmatic for the domain-specific approach to cognitive development. Although initially the primary focus of theory of mind research was on children’s acquisition of core conceptual distinctions (e.g., between belief and reality), the developmental relations between conceptual development and other cognitive functions have attracted considerable research interest in recent years. Interrelations among theory of mind or metacognitive knowledge, working memory, language acquisition, and executive functions have been studied empirically. Several theoretical proposals have been made to account for the observed associations. However, there is still little exchange between researchers working in the memory and information processing traditions and researchers working in conceptual development.

Thus, the main purpose of this book is to discuss and integrate findings from prominent research areas in developmental psychology that are typically studied in isolation but are clearly related. For instance, young children’s ability to regulate their actions (executive functions) is related to the ability to perform theory of mind (ToM) tasks that require the inhibition of prepotent responses (e.g., ignore one’s own knowledge of the situation and take the perspective of another person). An interesting question is whether executive functions represent a precursor of ToM or whether ToM understanding predicts the development of executive functions. Another interesting and understudied issue is to what extent children’s level of verbal ability (e.g., their understanding of sentences) and their working memory are important predictors of performance on both executive functioning and theory of mind tasks. For example, it is reasonable to assume that individual differences in vocabulary and verbal understanding are particularly important for predicting performance on executive functioning and ToM tasks in samples of young children (i.e., 3–4-year-olds), whereas among older children individual differences in working memory and executive functioning, rather than verbal abilities, may be better predictors of ToM performance.

During the last two decades, numerous studies have been conducted to investigate developmental trends in the areas addressed in the title of this book. More recently, several cross-sectional and longitudinal studies were carried out to test the specific predictions outlined previously. The chapters in this book give a detailed account of the major outcomes of this research. First, the state of the art concerning current understanding of the relevant constructs (working memory, ToM, executive functioning) and their developmental changes is presented, followed by chapters that deal with interactions among the core concepts. Thus, one outstanding feature of this volume is its focus on theoretically important relationships among determinants of young children’s cognitive development—topics considered to be hot issues in contemporary developmental psychology. Most of the contributions to the book are based on presentations made at an international workshop at Castle Hirschberg, Bavaria, in May of 2002.

In the first part of the volume, five teams of researchers present theoretical analyses and overviews of empirical evidence regarding the core constructs: working memory, executive functions, and theory of mind. Chapter 2, by Towse and Cowan, describes recent developments in the area of working memory. In its first section, it focuses on two different approaches to working memory, namely, the models of Baddeley and Hitch and of Cowan. This section ends with a comparison of these two approaches, which is stimulating because the two authors each stand behind one of the two models. Hence, the similarities are outlined without neglecting the distinct differences. The second section consists of an empirical approach comparing different working memory span procedures on the basis of their assumed processing demands. Here, the authors conclude that different span measures may reflect—depending on the age of the children—quite different processing demands (for similar arguments, see also chap. 3 by Zoelch and colleagues). The last section again takes a theoretical focus, when the authors emphasize that working memory development may not be adequately described by taking into account only the amount of information that has to be processed but that it is also important to consider variables that might be age dependent, such as processing speed, storage time, strategic variations, or variations in representational format. Finally, Towse and Cowan relate the concept of working memory to that of executive functions by referring to the core system of Baddeley’s (1996) model, that is, the central executive.

It is exactly here where the chapter 3 by Zoelch, Seitz, and Schumann-Hengsteler takes up: They discuss, on a theoretical as well as an empirical basis, how central executive processing within the Baddeley and Hitch working memory framework could be measured. A primary attempt is made at an empirical evaluation of Baddeley’s (1996) theoretical conceptualization of central executive processes within a developmental context. Therefore, the authors adjust seven different measures of central executive processes to children between 5 and 10 years of age. Each of these different operationalizations of central executive processing is discussed with respect to its processing demands—in particular, when different age groups will be faced with them. Empirically, Zoelch et al. demonstrate different developmental trends for the four different central executive subfunctions and report a correlational pattern that is in accordance with Baddeley’s theoretical assumptions. Furthermore, they discuss on the basis of their findings the criteria that should be taken into account when creating and evaluating working memory measurement tools within a developmental context.

In the following chapter by Zelazo, Qu, and Müller, the focus is switched from working memory to the role of executive functions (EF). The main part of the chapter is dedicated to reviewing the state of the art with respect to the definition of EF. Here the authors start with a functional approach, describing EF as mainly a planning procedure and—this is emphasized—as a domain-general construct. A crucial distinction is then made between hot and cool EF, depending on whether an action or thought occurs in a motivationally significant context or not. In particular, hot EF are relevant for social, emotional, and moral development. At that point, the authors point out a relation to ToM: Zelazo et al. argue on the basis of the CCC theory (Cognitive Complexity and Control) on complexity, that, basically, ToM is EF as expressed in the content domain of self and social understanding. They close the chapter by reporting a first study that documents the relative difficulty that children have with tasks that reflect both ToM and EF. In their conclusions, they clearly state that ToM doesn’t cause EF and EF doesn’t cause ToM; rather, both reflect the development of similar cognitive mechanisms and neural systems.

The chapters on working memory and EF are followed by an overview of the theory of mind literature. In the past 20 years, theory of mind has been one of the most active fields of cognitive development. Based on a conceptual analysis of what it means to be able to impute mental states to oneself and to others, Wimmer and Perner (1983) conducted the first systematic investigation of belief understanding in children. Since then, several hundred studies have addressed the issue of whether or not age-related changes in children’s solutions of the false belief task reflect a genuine developmental phenomenon. In chapter 5, Sodian reviews the developmental evidence for both first- and second-order belief understanding and the mastery of related concepts as well as the theoretical accounts that have been proposed for these phenomena. If belief understanding is a genuine developmental phenomenon (and there is good reason to believe that it is), what is it the development of? Whereas earlier accounts (simulation as well as conceptual change accounts) have focused on the mental domain, more recent theories have linked theory of mind development to broader cognitive changes, such as perspective-representation, the acquisition of syntax, and EF. Because the developmental relation of ToM and EF has been demonstrated in a large body of empirical studies, and because of its implications for neurocognitive development, the ToM-EF link has become an area of both theoretical and empirical innovation in recent years and is at the core of this book.

The second part of this volume deals with the interplay among the core concepts previously outlined and with developmental trends in the interaction. There is broad agreement that EF is a heterogeneous construct including inhibition, working memory, cognitive flexibility, and planning, as well as monitoring skills. Moses, Carlson, and Sabbagh (chap. 6) ask which aspects of executive function underlie the EF-ToM relation. The empirical findings strongly suggest that working memory, in combination with inhibitory control, is important for ToM development. There is ample evidence against a simple working memory account because ToM tasks with parallel working memory demands are solved at different ages, and only tasks with high inhibitory demands have been found to correlate closely with executive function measures. With respect to theories about the causal relation between executive control and ToM development, Moses et al. argue that the view that a certain level of executive functioning is a prerequisite for ToM development is best supported by the empirical data (especially by longitudinal data). The authors also argue that EF is probably important for conceptual development, that is, for ToM to emerge in the first place, rather than merely for overcoming performance problems, as expression accounts suggest.

In chapter 7, Bjorklund, Cormier, and Rosenberg take an evolutionary perspective on the ToM-EF relation. While evolutionary psychology generally favors domain-specific accounts, Bjorklund et al. argue that, in human evolutionary history, a domain-general process—the evolution of increased inhibitory ability resulting from brain expansion—led to better intentional control over individuals’ behavior and that this ability proved to be most highly adaptive in the social domain, where it was applied to dealing with everyday challenges in social groups. Enhanced social-cognitive abilities resulting from increased inhibitory control altered the hominids’ ecology and thereby produced new selective pressures that eventually resulted in the emergence of new, more sophisticated domain-specific social-reasoning abilities, supported by a theory of mind.

Whereas most studies of the EF-ToM relationship focused on first-order ToM, Sodian and Hülsken (chap. 8) studied advanced ToM abilities in children with deficient inhibitory control (children with attention deficit hyperactivity disorder [ADHD]). Consistent with the few studies previously conducted on ToM in children with ADHD, there was no difference between children with ADHD and normally developing controls in second-order belief understanding, as well as in a test of advanced social understanding. However, children with ADHD were shown to be delayed as indicated by a test of advanced understanding of epistemic states (knowing, guessing correctly, knowing by inference), requiring online representation of a person’s informational access, independently of behavioral outcome. These findings indicate that the development of EF may be important for certain aspects of advanced ToM development in elementary school age. The findings certainly support an expression account, but they may also be consistent with an emergence account, based on theoretical assumptions about an interaction of the conceptual content of mindreading tasks with their inhibitory demands.

Several contributions to this book emphasize that developmental changes in the prefrontal cortex relate to developmental changes observed for EF and ToM functioning. In chapter 9, Kain and Perner report on the current evidence from neuroimaging studies for the neural basis of ToM and EF. Although neuroimaging studies with children are still scarce, the empirical data summarized in this chapter show that both ToM and EF recruit spatially proximal brain regions. Regarding developmental differences, the overview given in this chapter indicates that, when working on EF tasks, children’s prefrontal regions are more broadly activated than those of adults. Overall, the authors emphasize that the relationship between ToM and EF performance depends considerably on the particular kinds of executive functioning and ToM tasks one is dealing with. Accordingly, generalizations about the relationship between the two constructs are difficult to justify based on findings from neuroimaging studies and thus should be avoided.

In chapter 10, Hasselhorn, Mähler, and Grube relate ToM to phonological working memory and verbal abilities. In particular, the authors look for so-called developmental dependencies between these three aspects of cognitive development in preschool children. The chapter starts with two empirical studies: In both of the studies, verbal ability aspects such as understanding, comparison, and word fluency as well as two measures of phonological working memory (i.e., digit span and nonword repetition) are incorporated and related to ToM. With respect to the latter, the focus is laid on first- and second-order false beliefs. On the basis of correlational and covariational data analyses, the authors discuss various potential developmental trajectories. Finally, they propose a hypothetical model, the relay race model, based on the assumption that, in the beginning, phonological working memory, and, later in development, verbal abilities are major pacemakers for the development of ToM.

Developmental disorders are especially important for understanding the EF-ToM relationship. Tager-Flusberg and Joseph (chap. 11) longitudinally studied the relationship between impairments in ToM and EF in autistic children. Their findings indicate that working memory, combined with inhibitory control and planning, contributed to ToM performance in autistic children and adolescents, independently of nonverbal mental age and language ability. Again, a simple working memory account was not supported because working memory by itself was not significantly correlated with ToM independently of general cognitive ability and language. Working memory combined with inhibitory control was a significant concurrent predictor of ToM, whereas planning ability predicted progress in ToM development in autistic persons. The authors discuss the implications of these findings for emergence versus expression accounts of the EF-ToM relationship, arguing that the combination of working memory and inhibitory control appears to be most closely related to performance aspects (expression) of ToM, whereas planning seems to be more deeply and conceptually related to ToM development—a conclusion that is also supported by independent research on the relation of ToM and planning abilities in normally developing children (Bischof-Köhler, 2000).

Although a few longitudinal studies tap developmental changes in some of the constructs discussed in this volume, only one recent study deals with the development of all of these concepts. Schneider, Lockl, and Fernandez (chap. 12) report on the first results of the Würzburg Longitudinal Study that was initiated in 2001 with 3-year-old children and is supposed to last until 2005. This longitudinal study was stimulated by a similar investigation conducted by Astington and Jenkins (1999), which emphasized the role of language development for the development of ToM and EF. Overall, the findings of the Würzburg study confirm and extend the findings by Astington and Jenkins, again highlighting the importance of language development (in particular, sentence comprehension) for children’s performance on both ToM and EF tasks when this relationship is investigated with comparably young children (i.e., 3-year-olds). Although the study is not complete (at the time of this writing), findings from subsequent measurement points seem to indicate that the importance of individual differences in language proficiency for ToM and EF performance is reduced with increasing age.

In the final chapter, Oberauer discusses the findings presented in the various chapters of this volume and their implications for our understanding of the interplay among ToM, EF, and working memory functions. The author already served as a discussant at the workshop at Castle Hirschberg and extends the comments he made at that occasion to the revised evidence presented in this volume. One of the major conclusions he draws from the available evidence is that a narrow definition of EF should be used in empirical studies, because (limited) construct validity can be demonstrated only for such a conception that focuses on supervisory and control processes, in particular, the inhibition of prepotent responses. Another conclusion is that working memory capacity seems to contribute to the emergence of ToM understanding, even though the existing evidence is not particularly strong. Finally, the author generates interesting speculations regarding the developmental function of the constructs under investigation in this volume, discussing the issue of whether they all come together and develop at about the same pace. The readers of this book are invited to take on these hypotheses and speculations and develop them further. We hope that they can share our discussant’s view and find the chapters valuable and helpful.

ACKNOWLEDGMENTS

The workshop at Castle Hirschberg, Bavaria, in May 2002, from which the contributions to the present volume originated, was funded by a grant...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Table of Contents
• Contributors
• 1 Introduction and Overview
• 2 Working Memory and Its Relevance for Cognitive Development
• 3 From Rag(Bag)s to Riches: Measuring the Developing Central Executive
• 4 Hot and Cool Aspects of Executive Function: Relations in Early Development
• 5 Theory of Mind—The Case for Conceptual Development
• 6 On the Specificity of the Relation Between Executive Function and Children’s Theories of Mind
• 7 The Evolution of Theory of Mind: Big Brains, Social Complexity, and Inhibition
• 8 The Developmental Relation of Theory of Mind and Executive Functions: A Study of Advanced Theory of Mind Abilities in Children with ADHD
• 9 What fMRI Can Tell Us About the ToM-EF Connection: False Beliefs, Working Memory, and Inhibition
• 10 Theory of Mind, Working Memory, and Verbal Ability in Preschool Children: The Proposal of a Relay Race Model of the Developmental Dependencies
• 11 Theory of Mind, Language, and Executive Functions in Autism: A Longitudinal Perspective
• 12 Interrelationships Among Theory of Mind, Executive Control, Language Development, and Working Memory in Young Children: A Longitudinal Analysis
• 13 Executive Functions, Working Memory, Verbal Ability, and Theory of Mind—Does It All Come Together?
• Author Index
• Subject Index