Momentary Improvement of Hand Sensation by Excluding

"Momentary improvement of hand sensibility by excluding vision" Access to the published version may require journal subscription. Abstract Purpose: The aim of this study was to investigate the effects of visual input on the results in a sensory testing procedure. Method: In 66 healthy persons sensory testing was done in a counterbalanced setting 1) with open eyes, and 2) blindfolded. The tested hand was placed behind a screen. Testing for tactile discrimination (2pd) and touch thresholds (Semmes-Weinstein monofilaments) was performed on the index finger of the dominant hand. Wilcoxon signed-rank test was used for the statistical analysis. Result: Two-point discrimination was significantly improved when the test was performed blindfolded compared with open eyes. Touch thresholds – a less complex task – showed no difference. Conclusion: This study demonstrated that removal of all visual input during sensibility testing results in improved test results compared to sensibility testing with visual input (opened eyes but the hand out of sight). The mechanism behind the improvement is likely rapid changes in the brain. Manipulation of visual input during sensibility testing, especially when performing tests that include an element of interpretation, influences the test result. These results highlight the importance of standardized procedures in sensibility testing.