Perceptual post-effects of left neck muscle vibration with visuo-haptic feedback in healthy individuals: A potential approach for treating spatial neglect

Among the techniques used to reduce spatial neglect’s symptoms, left neck muscle vibration (NMV) is alluring because it does not require the patient’s attentional co-operation. The aim of this study was to determine the type of NMV-associated feedback that induced the most intense and longest-lasting egocentric post-effects. Eighty-seven healthy individuals were randomly assigned to four intervention groups: “neck muscle vibration, blindfolded” (NMV), “neck muscle vibration with vision” (NMV + V), “neck muscle vibration and visual finger-pointing” (NMV + P), and “visual finger-pointing” (P). An eyes-closed finger-pointing subjective straight-ahead (SSA) test was carried out before the intervention, immediately afterwards, and 30 min afterwards. The results showed that only the NMV + P intervention induced a lasting leftward bias of SSA. In addition, the deviation reported in this intervention group differed significantly from those observed in the other interventions. The combination of visuo-haptic feedback and neck-somatosensory stimulation may enable a full, lasting intermodal recalibration, which could be potentiated by the attention level engaged during voluntary pointing. These outcomes highlighted that the NMV technique could easily integrate into routine occupational therapy sessions for treating various aspects of neglect disorders.