Analogue versus propositional representation in congenitally blind individuals.

Congenitally blind individuals are generally less accurate at mentally manipulating objects than sighted people. However, they often score higher on tests of short- and long-term verbal memory, and it has been suggested that an enhanced propositional representation compensates for inefficiencies in analogue visuospatial representation. Here, congenitally blind, blindfolded, and sighted participants recalled descriptions of relative object locations. In contrast to previous findings, the congenitally blind participants were as accurate as the blindfolded and sighted individuals at remembering the relative locations of objects, but their memory for the verbatim structure of presented descriptions was worse. We propose that, like sighted people, the congenitally blind spontaneously construct and remember analogue representations of object locations and that the performance discrepancies of the blind arise from the process of managing and manipulating these analogue representations.