Changing Body Representation Through Full Body Ownership Illusions Might Foster Motor Rehabilitation Outcome in Patients With Stroke.

Marta Matamala-Gomez,Elisa Pedroli,Giuseppe Riva,Fabrizia Mantovani,Clelia Malighetti,Pietro Cipresso,Olivia Realdon

doi:10.3389/fpsyg.2020.01962

Abstract

How our brain represents our body through the integration of internal and external sensory information so that we can interact with our surrounding environment has become a matter of interest especially in the field of neurorehabilitation. In this regard, there is an increasing interest in the use of multisensory integration techniques—such as the use of body ownership illusions—to modulate distorted body representations after brain damage. In particular, cross-modal illusions such as mirror visual feedback therapy (MVFT) have been widely used for motor rehabilitation. Despite the effectiveness of the MVFT for motor rehabilitation, there are some limitations to fully modify the distorted internal representation of the paretic limb in patients with stroke. A possible explanation for this relies on the physical limitations of the mirror in reproducing upper-limb distortions, which can result in a reduced sense of ownership of the mirrored limb. New digital technologies such as virtual reality (VR) and 360° videos allow researchers to create body ownership illusions by adapting virtual bodies so that they represent specific morphological characteristics including upper-limb distortions. In this manuscript, we present a new rehabilitation approach that employs full virtual body ownership illusions, using a 360° video system, for the assessment and modulation of the internal representation of the affected upper limb in stroke patients. We suggest modifying the internal representation of the upper limb to a normal position before starting motor rehabilitation training.

Highlights

How our brain represents our body has been a matter of interest in the field of neuropsychology and neuroscience for many years (Lhermitte, 1942)
Some studies have attempted to modulate body distortions in patients suffering from brain damage using cross-modal illusions based on multisensory integration techniques and the “free-energy principle” (FEP; Friston et al, 2010; Limanowski and Blankenburg, 2013), through mirror visual feedback therapy (MVFT) and the rubber hand illusion (RHI; Bolognini et al, 2015; Tosi et al, 2018), or by manipulating visuo-tactile stimulation feedback in amputee patients presenting a telescoped effect
We propose a new rehabilitation approach based on the use of full-body ownership illusions induced using a 360° video system designed to assess and later modulate the distorted internal body representation of the paretic upper limb in patients with stroke

Summary

INTRODUCTION

How our brain represents our body has been a matter of interest in the field of neuropsychology and neuroscience for many years (Lhermitte, 1942). Some studies have attempted to modulate body distortions in patients suffering from brain damage using cross-modal illusions based on multisensory integration techniques and the “free-energy principle” (FEP; Friston et al, 2010; Limanowski and Blankenburg, 2013), through mirror visual feedback therapy (MVFT) and the rubber hand illusion (RHI; Bolognini et al, 2015; Tosi et al, 2018), or by manipulating visuo-tactile stimulation feedback in amputee patients presenting a telescoped effect (which occurs when the distal part of the phantom limb is perceived as shrinking within the stump; Schmalzl, 2011) In this perspective article, we propose a new rehabilitation approach based on the use of full-body ownership illusions induced using a 360° video system designed to assess and later modulate the distorted internal body representation of the paretic upper limb in patients with stroke. We hypothesize that visual exposure to a corrected representation of the paretic limb through a virtual body ownership illusion generated in a 360° video should provide enough predictive errors, based on the FEP explained above, to update the distorted internal representation of the body to a normal one (Riva et al, 2017; Riva, 2018)

CONCLUDING REMARKS

ETHICS STATEMENT