Influence of Somesthesic Input on Subjective Visual Vertical in Dyslexic Children
Purpose: We explored the perception of subjective visual vertical (SVV) in dyslexic and non-dyslexic age, sex and QImatched.
Method: The SVV was evaluated with a laser and with or without foam under the feet. We performed an analysis ofvariance. Post hoc comparisons were made with the Fisher’s least significant differences test (LSD).
Results: Our results showed two significant effects for groups and for tilt condition: counterclockwise or clockwisedirection and a significant interaction between group, tilt and somesthesic condition: without and with foam underthe feet. More precisely, SVV response in the tilt counterclockwise condition with foam was found to be significantlyless accurate for the dyslexic group than for the non-dyslexic group. Also, SVV response in the tilt counterclockwisedirection was found to be significantly less accurate for both groups compared to clockwise direction. Moreover, inclockwise direction SVV process was found to be significantly less accurate in dyslexic than in non-dyslexic group.
Conclusion: These results suggest that the somesthesic information from foot sole affect SVV perception; such poorSVV responses could be due to an immaturity for heteromodal sensory integration needed in SVV perception.