http://neurology.thelancet.com Vol 5 September 2006 733

Media Watch

BooksSave a thought for social neuroscienceWhat is social neuroscience? Neuroscience is the study of what goes on inside brains and it deals, almost by defi nition, with individual organisms rather than collectives. The response of the brain to external stimuli has been the subject of research long before the science even had a name, but here is something new…Social animals, and above all human beings, need to be able to respond to many subtle behavioural cues from their conspecifi cs, not just the warning signals about potential predators, but also the body language of others in our social group when they express emotions such as fear, anger, joy, or distress. There’s a debate about just how recognition of these and many other less conspicuous clues are learned during development, but to survive in our social world a child has to acquire them early on and respond to them quickly, often below the level of conscious awareness. To do this, the child needs what is sometimes termed a theory of mind—that is, the capacity to recognise a non-solipsistic world in which other human beings also have thoughts, feelings, and intentions; in short, agency. Such a theory of mind is presumed to be absent, for example, in autistic children.

Do non-human species, in particular other primates, have even the rudiments of such a theory of mind? The suggestion that a monkey’s brain contains mirror neurons that respond not merely to the animal’s own intentional movements but also when it observes a conspecifi c performing a parallel action, implies, for some researchers at least, that they do. But most attention has properly been paid to the human situation. Until relatively recently, useful data could only be acquired from patients who had focal brain lesions, of whom the unfortunate American railwayman Phineas Gage has become the archetypal case. But in the past decades, the new imaging techniques, especially functional MRI and evoked response potentials, have opened up an almost uncharted universe for experiment and observation of normal brain functioning.

Social Neuroscience: People Thinking About Thinking People contains a collection of papers, apparently from a conference organised by the senior editor, that between them survey the present status of the subject, admittedly from an exclusively US perspective so that the rich vein of research opened by the Friths and their colleagues in London is present only in the form of references—a serious omission. The key brain regions, references to which recur in paper after paper, are the prefrontal and ventromedial cortex, the anterior cingulate, and the amygdala, the latter especially in reference to fear and anxiety-related emotions. Psychological properties and processes under study, either during development or in the adult, include emotional and social intelligence, self-awareness, non-cognitive language

processing, social pain, and racial and other forms of prejudice.

Rather than single out any one of these far-ranging topics and their authors in this brief review, some more general refl ections on the corpus as a whole seem more useful. All the authors take for granted is that it is appropriate to speak of a theory of mind, share a helpful developmental perspective, and reject one of the basic tenets of that group of self-defi ned evolutionary psychologists who argue that the mind is both innate and highly modular. For this group of social neuroscientists, modularity, even in its weakened form as proposed by Fodor, is out. But there remain many unresolved or unexplored issues: centrally, to what extent complex psychological and philosophical concepts, such as self-awareness or prejudice, can be given a tight enough experimental defi nition to be able usefully to map them onto a seat in the brain. As anthropologists remind us, such concepts are profoundly culture-bound, even where they may draw on certain human evolutionary universals, and the standard subject for such laboratory studies, the second year US psychology or neuroscience student, should not be taken as a universal representative of humanity.

Perhaps more troubling to neurobiologists is the question of how to interpret such mapping studies; at least one author in this collection has a reference to Gall, the founder of phrenology. If a particular brain region lights up—ie, shows increased local energy metabolism or electrical activity—in an experimental versus a control condition, is one entitled to argue that this region is the locus of the psychological function expressed in the experimental condition? Such localisational arguments have a long and contentious history in neuroscience. The cartographic signals take an average of activity over many millions of cells and relatively long periods of time, masking both temporal and spatial dynamics (a region may be apparently silent because some neurons are inhibited while others are active, for instance). In massively interconnected and re-entrant systems such as the brain, the hunt for specifi c locales for function may be a fool’s errand.

But I don’t mean to sound negative. Making neuroscience social in all senses of the term is an important ambition. Powerful as our imaging and conceptual tools are, they are as yet in their infancy and as so many of the authors in this useful book make clear that to understand the human condition, development is all-important. We should all watch carefully over the maturing of this particular infant and should thank its progenitors for their creative work.

Steven Roses.p.r.rose@open.ac.uk

Social Neuroscience: People Thinking About Thinking PeopleEdited by John T Cacioppo, Penny S Visser and Cynthia L PickettMIT Press, 2006£29·95, 328 pagesISBN 0 262 03335 6