Can vision of the body ameliorate impaired somatosensory function?

• Published in: Neuropsychologia Vol. 45; no. 5; pp. 1101 - 1107
• Main Authors: Serino, Andrea, Farnè, Alessandro, Rinaldesi, Maria Luisa, Haggard, Patrick, Làdavas, Elisabetta
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.01.2007; Elsevier Science
• Subjects: Adult; Adult and adolescent clinical studies; Arm - physiology; Biological and medical sciences; Body representation; Brain Damage, Chronic - complications; Brain Damage, Chronic - physiopathology; Brain plasticity; Discrimination (Psychology) - physiology; Female; Humans; Male; Medical sciences; Multisensory perception; Organic mental disorders. Neuropsychology; Perceptual Disorders - etiology; Perceptual Disorders - physiopathology; Perceptual Disorders - rehabilitation; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Somatosensory deficits; Somatosensory Disorders - etiology; Somatosensory Disorders - physiopathology; Somatosensory Disorders - rehabilitation; Stereognosis - physiology; Touch - physiology; Vision, Ocular - physiology; Visual Perception - physiology; Multisensory perception; Brain plasticity; Body representation; Somatosensory deficits; Human; Vision; Central nervous system; Plasticity; Representation; Intermodal perception; Body; Encephalon
• ISSN: 0028-3932; 1873-3514
• DOI: 10.1016/j.neuropsychologia.2006.09.013

Viewing the body is reported to improve tactile acuity [Kennett, S., Taylor-Clarke, M., & Haggard, P. (2001). Non-informative vision improves the spatial resolution of touch in humans. Current Biology, 11, 1188–1191]. The aim of the present study was to investigate whether this effect might be useful in improving somatosensory deficits of brain damaged patients. To support this proposal, we firstly tested the hypothesis that vision might modulate tactile performance when tactile information is limited. Thirty-two healthy subjects performed a two points discrimination task (2PDT) in three conditions: looking at their stimulated forearm, at a neutral object or at a rubber foot. The results showed that the effectiveness of visual enhancement of touch varies as a function of subjects’ tactile acuity. Moreover, the accuracy in 2PDT was higher when viewing their arm only in subjects with lower tactile sensitivity. To directly demonstrate that viewing the body might ameliorate tactile deficits, the same experiment was conducted on 10 brain damaged patients suffering a reduced somatosensory sensitivity. An amelioration of the performance was found in viewing arm condition. These findings suggest that the interaction between different sensory modalities might be effective in ameliorating deficits in single modalities.