book review

Three main concepts emerge from this Monkey see, monkey do book that are of particular interest to neuroscientists: the role of sequence learn- ing in imitation, the role of hierarchical structures in imitated actions and the crit- The Imitative Mind: Development, ical role of fronto-temporal interactions for Evolution and Brain Bases action and imitation. Andrew Whiten addresses comparative imitative edited by Andrew N. Meltzoff and Wolfgang Prinz sequence learning in normal and autistic Cambridge University Press, Cambridge, UK, 2002. $65.00 children and in apes. Interestingly, hardcover, pp 364 sequence learning has been frequently studied in in the last Reviewed by Marco Iacoboni ten years, but the neural basis of sequence learning within an imitative task has not yet been addressed. It is to be hoped that this book will stimulate such study. Robert Byrne investigates hierarchy in imitation in great apes, and Gattis, Bekkering and Scientific interest in the study of imitation introductory remarks, which concisely Wolschlager do the same in their explo- dates back to Darwin, who wrote detailed and effectively address the renewed inter- ration of goal-oriented imitation in chil- descriptions of mimicry in animals. There est in imitation and the approaches used dren. Recent imaging data suggest that a is now a rapidly growing neuroscience lit- to study its functional and neural mech- critical neural structure for goal-oriented erature on imitation and its related func- anisms. Most of the book’s merit, howev- imitation in humans is the inferior frontal http://www.nature.com/natureneuroscience tions, with studies ranging from er, is in the chapters themselves, most of gyrus, and precisely Brodmann area 44, single-unit recording to brain imaging and which are skillfully written such that their which is considered the human homolog computational approaches. For even the relevance goes beyond the limits of the of area F5 of the macaque brain, a premo- most reductive neuroscientist, imitation is discipline at hand and illuminates issues tor area containing mirror neurons. The of interest because it requires the percep- relevant to neighboring disciplines as well. chapter by Perrett and colleagues describes tion of motion and body parts, the inte- The two editors are leading figures in systematically the visual properties of neu- gration of these percepts with motor plans, the fields of developmental and experi- rons in the anterior sector of the superior and finally the control and execution of mental , and their respective temporal sulcus. These neurons have visu- those motor plans. The Imitative Mind is research contributions blend well con- al properties that are very similar to those among the first books to address the neur- ceptually. Andrew Meltzoff revolutionized of premotor mirror neurons. It is natural al bases of imitation. It is a survey of the world of in to assume some level of interaction empirical work on imitation that provides the 1970s when he showed that very between superior temporal and inferior a well-integrated view of imitative behav- young infants (the youngest was only 42 frontal neurons in action perception and

© Group 2003 Nature Publishing ior and its neural mechanisms by drawing minutes old) have some rudimentary imi- imitation. Recent imaging work has started from a wide range of disciplines in the tative ability. His findings overturned the addressing this issue empirically. behavioral and brain sciences. Indeed, the then-dominant paradigm of ‘learning to The book is also well defined by what study of imitation necessarily requires an imitate’ proposed by Piaget, and actually is left out. Recent computational and interdisciplinary approach that reaches suggested that babies learn by imitation. robotics approaches, strongly tuned toward well beyond the boundaries of the neuro- Wolfgang Prinz has framed his experi- an understanding of the mechanisms sciences. Traditionally the target of study mental work within a model that assumes favoring imitation learning, are not dis- in comparative and developmental psy- shared codes for perception and action, cussed. Psychological models that address chology, imitation is also studied in which fits nicely with the developmental experience-dependent mechanisms anthropology and artificial intelligence. evidence provided by Meltzoff’s work. encounter the same fate. In a way, this The book is divided into three sec- The recent discovery of ‘mirror neurons’ makes sense. The work of Meltzoff has tions: the first presents work from devel- in the macaque—premotor neurons that been interpreted, more by others than by opmental and comparative psychology, fire both when monkeys perform an Meltzoff himself, within a strong, albeit the second from experimental and cogni- action and when they observe another unnecessary, nativistic framework. More- tive psychology and the third from neu- animal performing that action—by the over, the action-perception model of Prinz roscience. Although this structure would group led by Giacomo Rizzolatti seems to is not heavily concerned with the question not seem to favor cross-talk between the be the natural neuroscientific counterpart of whether the sharing of perceptual and chapters and topics addressed by different of Meltzoff’s developmental psychology motor codes is shaped by experience or disciplines, the book succeeds in achiev- work and of Prinz’s experimental psy- hard-wired. Although The Imitative Mind ing a high level of integration. Part of this chology work. Needless to say, mirror does not take a strong position on the issue success is certainly due to the editors’ neurons have a central role in this book. of innate versus experience-dependent imi- Rizzolatti and colleagues clearly describe tation, I would not be surprised if the book Marco Iacoboni is in the Ahmanson Lovelace most of their basic findings in one chap- is perceived more on the ‘nature’ side of the Brain Mapping Center, David Geffen School of ter, and several other contributors refer to nature–nurture continuum. Even if so per- Medicine at UCLA, 660 Charles E. Young Drive mirror neurons in their chapters or invoke ceived, I am convinced that even those who South, Los Angeles, California 90095, USA. mirror neurons to support and explain land more on the ‘nurture’ side of the con- email: [email protected] some of their findings. tinuum will find the book worth reading.

nature neuroscience • volume 6 no 2 • february 2003 109