From action to interaction: mechanisms underlying the acquisition and control of shared action representations, and their social effects

People copy each other all the time, often without realising it. This behaviour - imitation - is important. It helps us get along with other people: if we like someone, we tend to copy them more, and vice-versa, if someone copies us, we tend to like them more. We can also use imitation to learn new skills. However, imitation can also have unwanted effects: people copy unhealthy behaviours such as smoking, and even anti-social behaviour such as rioting, especially when they feel part of a group.

Imitation is a behaviour that is thought to rely on "mirror" neurons, which are cells in the brain that are active when we perform an action and also when we see someone else perform the same action. This research project investigates both imitation behaviour and the responses of mirror neuron areas in the brain. The project has two aims. The first is to understand how we acquire the ability to imitate other people. The second is to investigate how we control imitative behaviour, and in particular how our ability to control imitation is affected by the social context when we feel part of a group.

The experiments in the first theme - acquisition of imitation - are testing a theory which suggests that we need to learn to imitate. The theory states that the more experience we get of seeing and doing the same action at the same time, the better we will be at imitating that action in the future. Because we are generally already very good at imitating, the best way to test this theory in adult volunteers is to give people training where they see and do different actions at the same time. If the theory is correct, this training should reduce imitation of these actions, and change the responses of mirror neuron areas. Dr Catmur has carried out several experiments which show that this is indeed what happens after this kind of training. However, those experiments used very simple actions, so the next step in testing the theory is to carry out the same kind of training with more complex actions. The first two experiments will do this. The third experiment will test another important prediction of the theory, which is that for actions like facial expressions, when we can't normally see the outcome of our own actions, receiving visual feedback should help us to improve imitation. This experiment could help design training methods for people who have trouble imitating (such as people with autism), or to improve imitation learning of skills, sports, or dance.

The second theme investigates how the brain controls imitation in a social context. Previous work has shown that people imitate more when they are focused on being part of a group, rather than on being an individual. Another piece of research has identified the areas of the brain that control how much we imitate. The new theory being tested in this theme brings these two pieces of research together and suggests that the reason we imitate more when we are focused on being part of a group is that we are less able to control how much we imitate. Volunteers will do a simple imitation task while their brain activity is measured in a brain scanner. At the same time, they will either focus on being part of a group, or on being an individual. The connections between brain areas involved in controlling imitation and mirror neuron areas will be measured. If the theory is correct, then when the volunteers focus on being part of a group, these connections should be reduced. This means the volunteers will be less able to control their imitation, so they should imitate more. This research has implications for people's behaviour in group situations. If people are less able to control imitation of others when they are in a group, then if we don't want people to imitate undesirable behaviour, perhaps we need to find ways to make them feel more individual. On the other hand, when imitation within a group is desirable, we should try to increase the degree to which people feel part of the group.

Who will benefit from this research?

One set of beneficiaries of the research in Theme 1 are practitioners who use interventions based on action observation or imitation training. For example this could be in the rehabilitation of stroke patients; in the treatment of patients with syndromes such as complex regional pain syndrome in which sensorimotor functioning is impaired; or to improve social interaction in autism spectrum conditions.

The research in Theme 2 is more theoretical at this stage, but may ultimately inform policy where imitative group behaviour is concerned. These impacts will therefore be more long-term. Potential beneficiaries will be policy makers in a diverse range of fields where the effects of group membership on behaviour are of interest. This could include policy makers interested in the behaviour of large groups in public order situations, or those working in the areas of health behaviours or in food choice, for example. Other groups who may be interested in the long-term impact of the research in Theme 2 include advertising and marketing professionals who may be seeking new ways to influence consumer behaviour, and for whom imitative group behaviour is of interest from an economic perspective.

How will they benefit from this research?

Theme 1 will benefit practitioners who work in the various different areas of clinical intervention detailed above, by providing theory-based evidence for the best way to apply imitation training in order to improve shared action representations. Imitation training is already used as an intervention in some of these conditions, e.g. to improve social outcomes in autism spectrum conditions; the research in Theme 1 will allow practitioners to design more effective interventions with a strong theoretical and empirical basis. More efficient interventions should be more cost-effective and less time-consuming, leading to benefits for patients and savings for health care providers in the medium- to long-term.

The research in Theme 2 will benefit policy makers and others interested in the effects of group membership on imitative behaviour. The research should lead to a greater understanding of the neural mechanisms underlying the control of imitative behaviour. It will also clarify the effect on imitative control of manipulations such as emphasising individuality. In the long term this will lead to more effective policies for controlling unwanted imitative behaviour, which may be applied across a range of different areas. It may also lead to more effective ways of manipulating imitative behaviour in a consumer setting.