Haptic Pictures, Blindness, and Tactile Beliefs: Preliminary Analysis of a Case-Study

Research on the identification of raised-outline drawings (haptic pictures) indicates that blind and sighted individuals process pictorial information similarly. To explain this similarity, the partial overlap hypothesis argues that pictorial representation is constrained by principles grounded on objective shape perception that are shared by vision and haptics. In contrast, the tactile beliefs hypothesis maintains that such similarity is not given by our tactile experience, but by indirect, meaning-based representation of such experience. In this case-study, a 13-year old child born completely blind was invited to explore and identify a set of haptic pictures. He then was invited to explain, verbally and/or by drawing, why he believed that the referents he suggested identified accurately the depicted objects. Identification and recognition memory of haptic pictures were interrelated, but unrelated to tactile beliefs. The findings support the partial overlap hypothesis.