Exploring the characteristics of imitation in Parkinson's disease

Parkinson's disease is a common neurological disorder, which has a profound effect on movement. People find it hard to initiate movements and often make movements that are smaller than they should be, such as taking shorter steps. Improving their movements can lead to significant benefits in quality of life. One way that this is done currently is using cues, such as markers on the floor to help increase their step length or sound cues to help time their steps. This project will investigate another possible way of eliciting movements in Parkinson's - imitation.

When we imitate someone, we copy their movements and receive a great deal of information from watching them. Think how much easier it is to copy a movement, like a tennis serve, than to follow written instructions. One of the reasons for this is that even when we just watch a movement, the areas of our own brain that are involved in generating our own movements become active. This means we are primed to make the same movement ourselves and this could be a route to facilitating movements for people with Parkinson's. However, despite the obvious potential for imitation to be used therapeutically, there has been very little research into imitation in Parkinson's. Previous studies have mostly looked at the imitation of gestures and measured only gross errors, such as making whole movements in the wrong order, rather than looking in detail at how fast or effective the imitated movements are. One study, however, suggests that imitation has the potential to improve movements in Parkinson's as people with Parkinson's were faster to reach after watching someone else reaching for the same target. This project builds on and extends this observation.

We will examine how effective imitation is at improving movement in people with Parkinson's, compared to a group of healthy volunteers of a similar age. We will ask them to copy a simple sequence of hand movements from a video clip, comparing this to when they are instructed verbally to make the hand movements. Measuring the speed and distance that they move their hand will tell us how effective their movements are. Monitoring where they are looking, as they observe the movement, will also tell us whether they are watching the movement in a similar manner to healthy participants. Using these methods, we will compare imitation under different conditions. For example, comparing imitating a moving hand versus a moving square will tell us whether seeing a real human action is more effective than an abstract movement. We will also examine whether imitation is improved in Parkinson's by observing the hand move towards visible targets, changing the perspective of the observed movement (as if sitting behind rather than opposite the actor moving their hand) and changing the speed of the observed movement so it closely matches the person's own movement speed. Finally, we will find out if imitation is more effective if the person makes their own movement at the same time as, or after they have finished watching, the observed movement. As a secondary aim, we will compare the healthy older volunteers to a group of young volunteers to discover any changes in imitation with age.

Finding out the answers to these questions will improve our understanding of how Parkinson's affects behaviour. Moreover, it will inform the development of therapeutic interventions and day-to-day strategies that use imitation, which have the potential to improve the quality of life of people with Parkinson's. To make our project as relevant as possible for interventions and everyday life for people with Parkinson's, our research team includes a physiotherapist, a neurologist and a representative with Parkinson's. In addition, finding out how a behaviour is affected by a disease that changes the brain can provide clues about how the behaviour is normally produced. Thus, our findings will also contribute to our general understanding of imitation in healthy people.

This project will produce the scientific groundwork to inform the design of therapeutic interventions involving imitation for people with Parkinson's. Using a behavioural intervention to improve their significant and disabling motor symptoms has the potential to improve the quality of life of people with Parkinson's and of their family and carers in a cost-effective manner. This could have widespread benefits since Parkinson's affects approximately 1 in 500 people and is estimated to cost the UK up to 3.3 billion annually (Findley, 2007). Our findings may also inform the use of imitation to promote healthy ageing.

The immediate beneficiaries of our research findings will be other researchers and practitioners (cognitive neuroscientists, physiotherapists, neurologists) who may develop new therapeutic interventions based on imitation or use our findings to drive further research. Researchers developing technology to support interventions may also benefit from our findings. To ensure that such interested parties are able to access and use our findings, we will hold a multidisciplinary workshop on Parkinson's and imitation in year 3 of the grant, to discuss our findings and other relevant research (see Pathways to Impact for more details). We will also disseminate our findings widely, to multidisciplinary audiences by targeting conferences and journal articles that reach Parkinson's researchers and practitioners (see Academic Beneficiaries for details). This will be facilitated by the breadth of our research team.

People with Parkinson's and practitioners who work with them (such as nurses, physiotherapists and occupational therapists) may also benefit immediately from our findings, which may inspire changes in their day-to-day lives or to their practice. For example, imitation could be emphasised more strongly in exercise programmes for people with Parkinson's or a carer might be able to use a type of imitation to help a person with Parkinson's who is "frozen". Hence, we will target people with Parkinson's via talks and articles in newsletters and target practitioners who work with people with Parkinson's via talks and training events (see Pathways to Impact for more details). Raising interest and awareness of imitation will also be important with regard to the development and trialling of interventions involving imitation. In year 3 of the grant, we will apply for local funding to collect pilot data for an imitation training intervention based on our findings, in a small number of participants (N=5). Together with the results of the proposed project, this will form the basis of a larger project to test the therapeutic efficacy of an imitation-based intervention. This might involve exercise or physiotherapy interventions incorporating imitation and could involve imitation of instructors or use technology (e.g. avatars). We anticipate that such interventions could be more widely available within 5-6 years.

We also anticipate that our patient representative and other people with Parkinson's involved in discussing the research at our workshop (see Pathways to Impact) and at local groups, as well as some of the participants, may benefit personally from the opportunity to be involved in the research project, as well as to discuss and influence our research. There will also be longer-term impact from training the post-doctoral researcher working on this project over the course of the project. They will gain experience in working in a cross-disciplinary team, as well as communicating with others outside their field and to the general public.