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Manual Therapy 16 (2011) 40e41

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Manual Therapy

journal homepage: www.elsevier .com/math

3rd International conference on movement dysfunction 2009

Evidence from cognitive neuroscience supports action observation as part of anintegrated approach to stroke rehabilitation

Paul Holmes*

IPR, Department of Exercise and Sports Science, Manchester Metropolitan University, Hassall Road, Alsager, Cheshire, ST7 2HL, United Kingdom

a r t i c l e i n f o

Article history:Received 31 March 2010Received in revised form28 June 2010Accepted 29 June 2010

Keywords:StrokeAction observationPsychology

* Tel.: þ44 161 247 5342; fax: þ44 161 247 6375.E-mail address: p.s.holmes@mmu.ac.uk.

1356-689X/$ e see front matter � 2010 Elsevier Ltd.doi:10.1016/j.math.2010.06.011

a b s t r a c t

This is an invited extended abstract from 3rd ICMD.� 2010 Elsevier Ltd. All rights reserved.

This review of cognitive neuroscience research aims to showthat observing meaningful actions, for example, using a rowingmachine (Fig. 1), can contribute positively to the stroke rehabili-tation process.

Following a cerebrovascular accident, individuals may be leftwith chronic motor impairment (e.g. hemiplegia), and cognitiveand psychological disability. Fortunately, recent advances in brainimaging have led to a greater understanding of the mechanisms ofpost-stroke recovery. This knowledge has been essential for opti-mizing the efficacy of interventions aimed at promoting motorrecovery. All forms of neural reorganisation are possible followingstroke and include: synaptogenesis; diaschisis, sprouting fromsurviving neurons; and recruitment of functionally homologouspathways (Rossini, Calautti et al., 2003) Therefore, any functionalpost-stroke intervention should attempt to enrich and optimiseneural stimulation in order to promote this brain plasticity.Unfortunately, many traditional therapies have tended to focus onthe recovery of prescriptive physical functions and on theresumption of generic activities of daily living and, in so doing, haveneglected previously valued activities which have personalimportance to individuals (Cott, Wiles et al., 2007). Research thathas attempted to address some of these concerns, by consideringthe effectiveness of motor imagery after stroke, has suggested somepromising results (see Page, 2010 for a review). However, a numberof practical and procedural concerns still remain (see Holmes,

All rights reserved.

2007). Until recently, video presented practical problems for theamateur user; cost, size of equipment, technological understandingof hardware and editing software were all barriers to its use. Thedevelopments in ubiquitous digital media now allow for the quickand easy production of high definition images that can addressimagery generation and ability problems, and provide relevantcontextual information. As well as the methodological benefits ofthis approach, action observation has also received support fromthe neuroscience literature.

Cortical activity in parieto-frontal circuits during action obser-vation has been studied extensively over the past two decades;neurons in these areas being proposed to possess mirror propertiessince they are active during both action execution as well as actionobservation. Whilst, debate is still ongoing regarding the involve-ment of these circuits in, for example, social cognition and actionand intention understanding, there is growing evidence that theycontribute to the motoric understanding of goals and intentionsthat comes with action observation of self and others.

From data in our own studies, we have demonstrated indirectevidence for some of these behaviours to support our work withstroke patients. Using electroencephalography (EEG) during theobservation and execution of non-object-related movements,Calmels, Holmes et al. (2006) studied event-related desynchroni-zation and synchronization of brain activity prior to, and during,observation and execution of finger movements (typical of thoseused in stroke rehabilitation) in four brain frequency bands. Theresults revealed that there was no significant difference in EEGcortical activity between the action observation condition and theexecution conditions. Whilst there was not an identical match of

Fig. 1. Patient engaging with rowing machine DVD. In this example, the visualperspective is first person. The viewing behaviour was selected by the patient.[Photograph used with patient’s permission].

P. Holmes / Manual Therapy 16 (2011) 40e41 41

EEG cortical indices, this study provided indirect support for theexistence of a mirror neuron system in humans that could supportclinical interventions. The nature of the cortical activity revealed inthis, and similar studies, suggests actioneobservationmay facilitatethe physical therapies used during traditional treatments.

We have also investigated action observation and the existenceof a motor-resonance mechanism in the human brain using trans-cranial magnetic stimulation (TMS). Observation of an action, in theabsence of overt movement, modulates the excitability of the cor-ticospinal pathwaywith a resultant increase in the amplitude of themotor evoked potentials (MEPs) specific to the muscles involved inthe observed action. MEPs during the observation of a ball pinchingaction (again, similar to tasks in some rehabilitation therapies) wasfacilitated when compared to observation of a static hand or a blankscreen, irrespective of whether participants had performed thesame ball pinching action prior to observing it. Furthermore, the

MEP amplitude was only modulated in a specific, functional fingermuscle (FDI) during the action observation. Taken together, the EEGand TMS data provide evidence for a cortical and skeletomuscularinvolvement during action observation that could be seen to befacilitative within a stroke rehabilitation context.

Using these findings to support our applied work with strokegroups, we follow an in-depth interview procedure to identify:contextually-relevant and meaningful actions; the importantstimuli associated with the actions; and patient’s behavioural andemotional responses to such stimuli. These scripts are used to directhighly individualised DVDs to recreate personally meaningfulactions. Our findings from case studies (Chatterton, Ewan et al.,2008), and group-based studies (Ewan, Kinmond et al., 2010),provide strong psychosocial and functional activity support for theprocedure and the use of action observation as an adjunct to moretraditional physical therapies.

1. Summary

The research reviewed here provides evidence to support theuse of action observation in stroke rehabilitation. The datasupports, in part, (i) a spatio-temporal similarity between centralmarkers of action execution and action observation and(ii) increased MEP amplitude during action observation. Theapplication and extension of these findings will reveal how actionobservation can support physical therapies for improvements inmotor function and affective behaviour and allow patients to returnto activities which were valued pre-stroke (Robison, Wiles et al.,2009).

References

Calmels C , Holmes PS, Jarry G, Leveque J-M , Stam CJ . Cortical activity prior to, andduring, observation and execution of sequential finger movements. BrainTopography 2006;19:77e88.

Chatterton H, Ewan L, Kinmond K, Haire A, Smith N, Holmes P. Observation ofmeaningful activities: a case study of a personalized intervention on post-stroke functional state. Journal of Neurologic Physical Therapy 2008;32:52e9.

Cott C, Wiles R, Devitt R. Continuity, participation and transition: preparing clientsfor life in the community post-stroke. Disability and Rehabilitation 2007;29:1566e74.

Ewan LM, Kinmond K, Holmes PS. An observation-based intervention for strokerehabilitation: Experiences of eight individuals affected by stroke. Disabilityand Rehabilitation; 2010:1e10. doi:10.3109/09638288.2010.481345.

Holmes PS. Theoretical and methodological problem for imagery in stroke reha-bilitation: an observation solution. Rehabilitation Psychology 2007;52:1e10.

Page SJ. An overview of the effectiveness of motor imagery after stroke: a neuro-imaging approach. In: Guillot A, Collet C, editors. The neurophysiologicalfoundations of mental and motor imagery. New York: Oxford University Press;2010. p. 145e59.

Robison J, Wiles R , Ellis-Hill C, McPherson K, Hyndman D, Ashburn A. Resumingpreviously valued activities post-stroke: who or what helps? Disability andRehabilitation 2009;31:1555e66.

Rossini PM, Calautti C, Pauri F , Baron JC . Post-stroke plastic reorganisation in theadult brain. The Lancet Neurology 2003;2:493e502.