Exclusion Learning and Emergent Symbolic Category Formation in Individuals With Severe Language Impairments and Intellectual Disabilities

Abstract

We evaluated formation of simple symbolic categories from initial learning of specific dictated word-picture relations through emergence of untaught or derived relations. Participants were 10 individuals with severe intellectual and language limitations. Three experimental categories were constructed, each containing 1 spoken word (Set A), 1 photograph (Set B), and 1 visual-graphic "lexigram" (Set C). Exclusion-based learning procedures were used to teach first the 3 auditory-visual relations (A-B relations) and then the 3 visual-visual relations (B-C relations) for each category. Seven participants acquired these initial relations. The untaught relations C-B and A-C were then assessed to evaluate the emergence of symbolic categories. Participants demonstrated virtually error-free performances on C-B and A-C derived relations. The study helps to define operationally a highly useful procedural path for systematic instruction in symbolic functioning for persons with intellectual and language disabilities associated with autism and other neurodevelopmental disorders.