Comparison of Touch Sensation among Congenital Blind, Early Onset Blind, and Late Onset Blind, Using Moberg’s Test

BACKGROUND The objectives of the study were to assess and compare touch sensation of dominant and non-dominant hands among blind since birth, early onset blind & late onset blind participants using Moberg’s test and determine if the time of onset of blindness affected the touch sensation. METHODS 50 blind participants from various colleges in Mumbai were assessed. Detailed history about onset of blindness, motor dominance etc. of blind was asked. Participants were instructed to pick up objects (suggested by Moberg) one at a time, as fast as possible, and place them into a box using dominant and non-dominant hands alternatively. Kruskal Wallis Test was used for analysis. RESULTS Average values of Moberg’s test of dominant & non - dominant hands of blind since birth versus late onset blind were statistically significant and those of early onset blind versus late onset blind were statistically significant. Average values of Moberg’s test of blind since birth versus early onset blind were not statistically significant. Thus touch sensation was improved more in blind since birth & early onset blind compared to late onset blind participants. CONCLUSIONS Thus we conclude that in the absence of visual stimuli, touch sensation in blind since birth and early onset blind is improved compared to late onset blind participants. KEY WORDS Blind, Cross - Modal Synaptic Plasticity, Substitution of Sense. Moberg's Pick - up Test, Critical Period