Cortical Functional Domains Show Distinctive Oscillatory Dynamic in Bimanual and Mirror Visual Feedback Tasks.

Salim M H Al-Wasity,Frank Pollick,Anna Sosnowska,Aleksandra Vuckovic

doi:10.3389/fncom.2019.00030

Salim M H Al-Wasity, Frank Pollick + Show 2 more

Open Access

https://doi.org/10.3389/fncom.2019.00030

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Abstract

It is believed that Mirror Visual Feedback (MVF) increases the interlimb transfer but the exact mechanism is still a matter of debate. The aim of this study was to compare between a bimanual task (BM) and a MVF task, within functionally rather than geometrically defined cortical domains. Measure Projection Analysis (MPA) approach was applied to compare the dynamic oscillatory activity (event-related synchronization/desynchronization ERS/ERD) between and within domains. EEG was recorded in 14 healthy participants performing a BM and an MVF task with the right hand. The MPA was applied on fitted equivalent current dipoles based on independent components to define domains containing functionally similar areas. The measure of intradomain similarity was a “signed mutual information,” a parameter based on the coherence. Domain analysis was performed for joint tasks (BM and MVF) and for each task separately. MVF created 9 functional domains while MB task had only 4 functionally distinctive domains, two over the left hemispheres and two bilateraly. For all domains identified for BM task alone, similar domains could be identified in MVF and joint tasks analysis. In addition MVF had domains related to motor planning on the right hemisphere and to self-recognition of action. For joint tasks analysis, seven domains were identified, with similar functions for the left and the right hand with exception of a domain covering BA32 (self-recognition of action) of the left hand only. In joint task domain analysis, the ERD/ERS showed a larger difference between domains than between tasks. All domains which involved the sensory cortex had a visible beta ERS at the onset of movement, and post movement beta ERS. The frequency of ERD varied between domains. Largest difference between tasks existed in domains responsible for the awareness of action. In conclusion, functionally distinctive domains have different ERD/ERS patterns, similar for both tasks. MVF activates contralateral hemisphere in similar manner to BM movements, while at the same time also activating the ipsilateral hemisphere. Significance: Following stroke cortical activation and interhemispheric inhibition from the contralesional side is reduced. MVF creates stronger ipsilateral activity than BM, which is highly relevant of neurorehabilitation of movements.

Highlights

A specific type of mirror therapy, which is based on mirror-visual feedback (MVF), has been used for the rehabilitation of different forms of neuropathic pain (Matthys et al, 2009; Deconinck et al, 2014), and for the rehabilitation of movement in stroke patients (Michielsen et al, 2011)
In order to achieve the MVF illusion, a mirror is placed in a midsagittal plane between the intact and the affected limb, so that the reflection of the intact limb in a mirror is superimposed onto the affected one (Ramachandran and Rogers-Ramachandran, 1996)
The numbers in brackets show the probability of the mentioned domain occurring in that Brodman Areas (BA)/anatomical location

Summary

Introduction

A specific type of mirror therapy, which is based on mirror-visual feedback (MVF), has been used for the rehabilitation of different forms of neuropathic pain (Matthys et al, 2009; Deconinck et al, 2014), and for the rehabilitation of movement in stroke patients (Michielsen et al, 2011). It has been suggested that the mechanisms that underlie MVF are related to mismatched integration between vision, tactile sensation and proprioception (Hunter, 2003; Egsgaard et al, 2011). Another hypothesis has suggested that the mirror neuron system (Rizzolatti et al, 2001) may play a role in the mechanism of mirror therapy (Rosén and Lundborg, 2005; Yavuzer et al, 2008), a systematic overview of MVF studies failed to confirm this hypothesis (Deconinck et al, 2014). Other theories have suggested that mirror therapy is a type of motor imagery, which creates visual feedback of the imagined limb movement (Stevens and Stoykov, 2003)

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