Tactile perception of line and dotted pictograms by sighted and blind people

Simplified pictures such as pictograms could be an easy way of providing written or pictorial information for non-braille readers. In this study, we compared the recognition rates for tactile pictograms drawn with lines but also with dots, as on pin array tablets. We also assessed the effect of size of the person's finger and observed that a broader finger led to poorer performance for line and dotted pictograms. The study included early blind, late blind and blindfolded sighted participants but the analysis showed no effect of visual status; rather, we observed an effect of braille usage. Line pictograms were easily recognized by all participants. However, for dotted pictograms, braille readers performed better than non-braille readers. An analysis of single items suggested that in order to be better recognized, dotted pictograms should be created with fewer dots and without any curves.