Individual differences in the capacity limitations of visuospatial short-term memory: Research on sighted and totally congenitally blind people

Explored visuospatial imagery capacity by asking blind and sighted people to follow an imaginary pathway through either 2- or 3-dimensional (3-D) matrices of different complexity. Ss in the 1st 3 experiments were 35 congenitally blind Ss (aged 15–60 yrs) and 35 sighted matched controls. Ss in Exp 4 were 12 sighted Ss, and those in Exp 5 were 32 sighted high school seniors with low or high visuospatial ability. The blind Ss appeared to use specific visuospatial processes in the task, but they had difficulty with 3-D matrices; sighted Ss had no such difficulty with 3-D matrices. On the other hand, when a 3-D pattern exceeded sighted capacity, the blind and sighted Ss showed similar patterns of errors. Further analyses suggest that both visuospatial processes and verbal mediation were used.