Elevation easier than plan for sighted and early-blind adults in a perspective-taking task

Piaget's 3-mountains task with impossible options: sighted, blindfolded, early and late blind participants

In Piaget's 3-mountains task, 3D objects - a cube, cone and sphere - sit on a square tabletop. They are portrayed in 2D pictures as elevations (projections to the sides) such as one with a square on the left, a triangle in the middle and a circle on the right. Three objects offer six elevations, of which four are possible and two impossible. The possibles are elevations from the sides of the table - front, left, right and rear. In the impossibles, an object in the corner of the table is shown in the middle of an elevation. Sighted, sighted-blindfolded, early- and late-blind adults judged the elevations as to side of the table or impossible. The results suggest similar spatial abilities across groups. The impossible options had mid-range accuracy for all groups, with reaction times like possible options. The sighted and blind participants may consider possible and impossible options sequentially, one item at a time.

Pointing to azimuths and elevations of targets: blind and blindfolded-sighted

Three groups of observers pointed to target circles in a path on the ground, in two parallel rows. Participants in one group viewed the circles and then pointed blindfolded. Those in a second group were blindfolded and then touched the circles with a stick while walking past them. Volunteers in the third group were blind adults, a diverse group, who also used a stick to detect the circles. For all three groups, as distance to the circles increased, pointing azimuths shrank and elevations increased. We suggest that directions to targets on major environmental surfaces may be appreciated similarly by the blind and sighted. We challenge the assumption that the principle of convergence to the horizon, available through vision because of the way in which visual angle decreases on the retina, is not available through touch.

Tactile drawing aesthetics and a blind woman’s drawings of sounds

This article makes four points. First, in making raised, tangible outline pictures, blind people can invent sophisticated treatments for topics they select themselves. Second, their drawings can be realistic. Third, they can also be metaphoric, in showing sounds for example. Fourth, their outline drawings use line for surface edges, and they incorporate aspects of perspective such as profiles. These points are illustrated by three drawings by EW, a blind woman. They are sketches of a couple waltzing, a guitar player, and a samba band. The account of line and profiles given here for the blind, this article argues, applies also to Palaeolithic art, as in Herzog’s ‘Cave of forgotten dreams’ and Cook’s ‘Ice age art: the arrival of the modern mind’.