Tactual Equivalence Class Formation and Tactual-to-Visual Cross-Modal Transfer

Five adults, two who were deaf-blind and three who were hearing-sighted but blindfolded for the experiment, learned the conditional discriminations AB and BC that consisted of complex tactual stimuli. Class-consistent responding to symmetry, transitivity, and equivalence probes demonstrated the emergence of tactual equivalence classes by four of the subjects. These data confirm that visual or auditory stimuli are not needed for the induction of equivalence classes. They also suggest that equivalence class procedures might facilitate the formation of communicational skills by individuals who are deaf and blind. Following the formation of the tactual equivalence classes by the two hearing-sighted adults, they immediately showed tactual-to-visual cross-modal generalization of equivalence relations. These results suggest that prior equivalence class formation facilitate the reliable emergence of cross-modal transfer.