Understanding other minds: linking developmental psychology and functional neuroimaging.

Key Words theory of mind, mentalizing, social cognition, cognitive neuroscience

* Abstract Evidence from developmental psychology suggests that understanding other minds constitutes a special domain of cognition with at least two components: an early-developing system for reasoning about goals, perceptions, and emotions, and a later-developing system for representing the contents of beliefs. Neuroimaging reinforces and elaborates upon this view by providing evidence that (a) domain-specific brain regions exist for representing belief contents, (b) these regions are apparently distinct from other regions engaged in reasoning about goals and actions (suggesting that the two developmental stages reflect the emergence of two distinct systems, rather than the elaboration of a single system), and (c) these regions are distinct from brain regions engaged in inhibitory control and in syntactic processing. The clear neural distinction between these processes is evidence that belief attribution is not dependent on either inhibitory control or syntax, but is subserved by a specialized neural system for theory of mind.

 
CONTENTS 
 
INTRODUCTION 
FUNCTIONAL NEUROIMAGING: STANDARDS 
  OF EVIDENCE AND INFERENCE 
DEVELOPMENTAL PSYCHOLOGY: BELIEF ATTRIBUTION 
    Inhibitory Control and Belief Attribution 
    Language and Belief Attribution 
    Beyond False Belief 
NEUROIMAGING: BELIEF ATTRIBUTION 
    Neuroimaging: Belief Attribution and Inhibitory Control 
    Neuroimaging: Belief Attribution and Language 
    Belief Attribution: Conclusions 
DEVELOPMENTAL PSYCHOLOGY: DESIRES, 
  PERCEPTIONS, EMOTIONS 
    Desires/Goals 
    Neuroimaging: Desires, Perceptions, and Emotions 
CONCLUSIONS 

INTRODUCTION

Unlike behaviorists, normal adults attribute to one another (and to themselves) unobservable internal mental states, such as goals, thoughts, and feelings, and use these to explain and predict behavior. This human capacity for reasoning about the mental causes of action is called a theory of mind. In the past 25 years, theory of mind has become a major topic of research, initially in developmental psychology and subsequently in other fields including social psychology, philosophy, and ethology.

Most recently, a new method for theory of mind research has joined the pack: functional brain imaging [especially functional magnetic resonance imaging (fMRI)]. The blood oxygenation level dependent (BOLD) signal measured by fMRI gives scientists unprecedented access to the hemodynamic changes (and indirectly to the neural activity) in the brain that are associated with psychological processes, fMRI may have by now exceeded all other techniques in psychology in terms of expense, growth rate, and public visibility. But many have wondered how much this new technology has actually contributed to the study of human cognition, and when--if ever--a finding from functional neuroimaging has constrained a cognitive theory.

In this review, we take the human theory of mind as a case study of real theoretical exchange between studies (and scientists) using functional neuroimaging and those using the more well-established techniques of developmental psychology, As such, this review will necessarily be selective. For more complete coverage of related research, we refer the reader to the many excellent recent reviews in the fields of cognitive neuroscience (e.g., Adolphs 2001, 2002, 2003; Allison et al. 2000; Blakemore & Decety 2001; Decety & Grezes 1999; Frith 2001; Frith & Frith 2000, 2003; Gallagher & Frith 2003; Gallese 2003; Greene & Haidt 2002; Grezes & Decety 2001; Puce & Perrett 2003; Siegal & Varley 2002) and developmental psychology (e.g., Baldwin & Baird 2001; Bartsch 2002; Csibra 2003; Flavell 1999; Johnson 2000, 2003; Meltzoff & Decety 2003; Wellman & Lagattuta 2000; Wellman et al. 2001).