The Developmental Cognitive Neuroscience Group focuses on neurocognitive development in typically developing children and adolescents, and in children, adolescents and adults with developmental disorders such as autism spectrum conditions. We are particularly interested in the development of the social brain - that is, the network of brain regions involved in understanding other people.

The social brain

Humans are inherently social. A large proportion of the human brain is involved in social interaction and understanding other people. The social brain is defined as the complex network of areas that enable us to recognise others and evaluate their mental states (intentions, desires, beliefs), feelings, enduring dispositions and actions. Brain areas involved in social cognitive processes include medial prefrontal cortex (mPFC), anterior cingulate cortex (ACC), inferior frontal gyrus, superior temporal sulcus (STS), the amygdala and anterior insula (see Figure on right). Over the past two decades, research has begun to shed light on how the brain enables the diverse set of functions that allow humans to understand and interact with each other. These functions range from the recognition of faces and bodily gestures to the evaluation of what another person is thinking or feeling, predicting what they are about to do next and communicating with them.

Our current research focuses on the development of the social brain during adolescence, and the functioning of the social brain in autism.

Adolescence

In the past decade or so, a number of structural magnetic resonance imaging (MRI) studies have shown that several cortical regions, in particular the PFC, parts of the temporal cortex and parietal cortex, as well as a number of subcortical structures, undergo substantial changes in white matter and grey matter density during the first two decades of life. In several brain regions, white matter volume tends to increase linearly during the first two decades and beyond while grey matter volume tends to decrease during adolescence. Some of the brain regions that are late-maturing include parts of the social brain.

Social brain development during adolescence

There is a rich literature on the development of social cognition in infancy and childhood, pointing to step-wise changes in social cognitive abilities during the first five years of life. However, there has been surprisingly little empirical research on social cognitive development beyond childhood. Only recently have studies focussed on development of the social brain beyond childhood.

Although there is no strong evidence that performance in mentalising tasks changes during adolescence, several fMRI studies of social cognition have shown that medial prefrontal cortex activity decreases between adolescence and adulthood. For example, the dorsal mPFC was found to be more active in adolescents than in adults in an fMRI study that involved thinking about one's own intentions (Blakemore et al. 2007). Adolescents (aged 12-18) and adults (aged 22-38) were presented with scenarios about intentional causality (involving intentions and consequential actions) or physical causality (involving natural events and their consequences). In both groups, intentional causality relative to physical causality activated the classic mentalising network including the mPFC, temporal poles and pSTS/TPJ. However, the dorsal mPFC was more active in adolescents than in adults during intentional causality relative to physical causality. A different activity cluster within the same region was negatively correlated with age over the whole group of participants. Conversely, a region in the right STS was more active in adults than in adolescents when they were thinking about intentional causality compared with physical causality.

In a second fMRI study, which was carried out by Stephanie Burnett, volunteers had their brain scanned when thinking about social situations that would cause many people to experience social emotions such as guilt and embarrassment. For example, in the Embarrassment condition, volunteers read sentences like, "Your dad started doing rock 'n' roll dances in the supermarket". Thinking about guilt and embarrassment situations activated the social brain in both adolescents and adults. However, the mPFC was more active in adolescents than in adults while the temporal pole was more active in adults than in adolescents (Burnett et al. 2008).

These results suggest that the neural strategy for thinking about intentions changes from adolescence to adulthood. Although the same neural network is active, the relative roles of the different areas change with age, with activity moving from anterior (mPFC) regions to posterior (temporal) regions.

Several recent fMRI studies have shown that activity in the mPFC during social cognitive tasks decreases between adolescence and adulthood (see Blakemore, 2008 for meta-analysis and figure).

Executive functions and cognitive control in adolescence

As well as social functions, we are interested in how the brain matures to en able cognitive control, a collection of brain processes that guide thought and behaviour in accordance with internally generated goals or plans. Inhibitory control, task switching and working memory have been investigated in children by various groups; it has been found that performance on executive function tasks continues to improve as late as adolescence and early adulthood. Our research focuses on novel tasks of cognitive control, for example tapping into the manipulation of self-generated thoughts. We are studying how performance on these tasks improves during late childhood and adolescence, in parallel to the development of social cognition. Iroise Dumontheil is running a research project on how rostral prefrontal cortex, or Brodmann area 10 (shown in the figure on right), a region that is thought to support both executive and social functions, develops during late childhood and adolescence, and how it might be divided in functionally dissociated sub-regions (Dumontheil et al. 2008).

Autism spectrum conditions

We are interested in how the social brain functions in autism spectrum conditions (ASC). Recent studies run by Zillah Boraston have shown that adults with ASC show selective impairments on the perception of emotion from simple animations (Boraston et al. 2007). We have also found that adults with ASC have trouble distinguishing between genuine and posed smiles (Boraston et al. 2008). In these studies, both the perception of emotion from animations and the ability to distinguish between genuine and posed smiles were related to degree of reciprocal social interaction problems experienced in the group with ASC.

The mirror neuron system

Some of our research focuses on action understanding and the mirror neuron system (MNS), that is the parts of the motor system that are also involved in the perception of others' actions. We have developed a behavioural paradigm that produces measurable interference between observed and executed actions (Kilner et al. 2003). When participants observe another human making incongruent movements (see figure on right) we find that this interferes with their own executed movements. This interference effect is specific to observed biological motion - when participants observe a robot, or even a video of a human moving like a robot, no interference occurs (Kilner et al. 2007).