TMR children's competence in processing negation

Previous researchers have suggested that TMR children lack the competence to process negation. Questions about the appropriateness of using reversible sentences to test comprehension and observations on TMR children's imitative processing of simple affirmative and negative sentences led to an experimental reexamination of the earlier findings. Institutionalized students ranging in age from 10 to 21 years with a mean IQ of 30 were asked to evaluate 16 picture pairs, 8 each for nonreversible and reversible sentences. Nonreversible sentences, both positive and negative, were interpreted correctly more often than reversible sentences. There was a significant correlation between comprehension and mental age. The results were interpreted as substantiating the adverse effect of sentence reversibility on comprehension and as evidence for the position that retarded children develop basic grammatical structures including negation at a relatively late age, but in normal interrelationship and sequence with other language and cognitive abilities.