title: Assimilation of virtual legs and perception of floor texture by complete paraplegic patients receiving artificial tactile feedback.
abstract: Spinal cord injuries disrupt bidirectional communication between the patient's brain and body. Here, we demonstrate a new approach for reproducing lower limb somatosensory feedback in paraplegics by remapping missing leg/foot tactile sensations onto the skin of patients' forearms. A portable haptic display was tested in eight patients in a setup where the lower limbs were simulated using immersive virtual reality (VR). For six out of eight patients, the haptic display induced the realistic illusion of walking on three different types of floor surfaces: beach sand, a paved street or grass. Additionally, patients experienced the movements of the virtual legs during the swing phase or the sensation of the foot rolling on the floor while walking. Relying solely on this tactile feedback, patients reported the position of the avatar leg during virtual walking. Crossmodal interference between vision of the virtual legs and tactile feedback revealed that patients assimilated the virtual lower limbs as if they were their own legs. We propose that the addition of tactile feedback to neuroprosthetic devices is essential to restore a full lower limb perceptual experience in spinal cord injury (SCI) patients, and will ultimately, lead to a higher rate of prosthetic acceptance/use and a better level of motor proficiency.
authors.affiliation: Neurorehabilitation Laboratory, Associação Alberto Santos Dumont para Apoio à Pesquisa (AASDAP), São Paulo, Brazil.
authors.forename: Solaiman
authors.initials: S
authors.lastname: Shokur
authors.affiliation: STI IMT, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
authors.forename: Simone
authors.initials: S
authors.lastname: Gallo
authors.affiliation: Edmond and Lily Safra International Institute of Neuroscience, Santos Dumont Institute, Macaiba, Brazil.|Alberto Santos Dumont Education and Research Institute, São Paulo, Brazil.
authors.forename: Renan C
authors.initials: RC
authors.lastname: Moioli
authors.affiliation: Neurorehabilitation Laboratory, Associação Alberto Santos Dumont para Apoio à Pesquisa (AASDAP), São Paulo, Brazil.|Associação de Assistência à Criança Deficiente (AACD), São Paulo, Brazil.
authors.forename: Ana Rita C
authors.initials: ARC
authors.lastname: Donati
authors.affiliation: Edmond and Lily Safra International Institute of Neuroscience, Santos Dumont Institute, Macaiba, Brazil.|Alberto Santos Dumont Education and Research Institute, São Paulo, Brazil.
authors.forename: Edgard
authors.initials: E
authors.lastname: Morya
authors.affiliation: STI IMT, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
authors.forename: Hannes
authors.initials: H
authors.lastname: Bleuler
authors.affiliation: Neurorehabilitation Laboratory, Associação Alberto Santos Dumont para Apoio à Pesquisa (AASDAP), São Paulo, Brazil.|Edmond and Lily Safra International Institute of Neuroscience, Santos Dumont Institute, Macaiba, Brazil.|Alberto Santos Dumont Education and Research Institute, São Paulo, Brazil.|Department of Neurobiology, Duke University, Durham, NC, USA.|Department of Biomedical Engineering, Duke University, Durham, NC, USA.|Department of Psychology and Neuroscience, Duke University, Durham, NC, USA.|Center for Neuroengineering, Duke University, Durham, NC, USA.
authors.forename: Miguel A L
authors.initials: MAL
authors.lastname: Nicolelis
mesh_terms: D000328:Adult; D001921:Brain / Q000503:physiopathology; D005246:Feedback; D005260:Female; D005430:Floors and Floorcoverings; D005528:Foot / Q000503:physiopathology; D006801:Humans; D007088:Illusions / Q000502:physiology*; D007866:Leg / Q000502:physiology*; D008297:Male; D010264:Paraplegia / Q000503:physiopathology*; D010465:Perception / Q000502:physiology*; D013119:Spinal Cord Injuries / Q000503:physiopathology / Q000534:rehabilitation; D013499:Surface Properties; D014110:Touch / Q000502:physiology*; D014584:User-Computer Interface; D016138:Walking / Q000502:physiology