Visual imagery without visual experience: evidence from congenitally totally blind people

We explored the ability of congenitally totally blind people (who were cont rasted with age-, sex- and education matched blindfolded sighted subjects) to perform tasks which are mediated by visual mental imagery in sighted peo ple. In the first (pictorial) task, subjects had to mentally compare the sh ape of the outline of three named objects and to indicate the odd-one-out. In the second (spatial) task the participants were asked to memorise the po sition of a target cube in two- and three-dimensional matrices, based on a sequence of spatially based imagery operations. In addition, during half of the trials of both imagery tasks subjects were required to perform a concu rrent finger tapping task, to investigate whether the blind subjects would be more dependent on spatial processing. Although blind participants made s ignificantly more errors than sighted participants, they were well able to perform the spatial imagery task as well as the pictorial imagery task. Int erference from the concurrent tapping task affected both groups to the same extent. Our results shed new light on the question whether early visual ex perience is necessary for performance on visual imagery tasks, and strongly suggest that vision and haptics may share common representations. NeuroRep ort 12:2601-2604 (C) 2001 Lippincott Williams & Wilkins.