Short Term Memory and Syntactic Structure in Educationally Subnormal Children

Is the cause of language deficiency in some children to be found in inadequate acquisition of linguistic rules or is poor functioning due to deficit on some psychological dimension ? A group of children in schools for the educationally subnormal were tested on a short term memory (STM) task. Materials were unstructured strings of words and twenty-four eight-word sentences manifesting different transformational rules. Seven levels of performance on unstructured strings (STM) were identified and the degree of facilitation provided by sentence structure of any kind was related to these levels. The most significant result was the differential effect of sentence types at different levels of STM. It was concluded that STM limitations may well account for some language deficiencies. Recent linguistic work suggests an explanation in terms of the different amounts of computation involved in the internal organisation of sentences of the same length. Subjects will fail to process such sentences as make demands on STM beyond their capacity.