THE ROLE OF HIERARCHICAL MORPHOLOGICAL STRUCTURE - A CASE-STUDY

This study addressed the question of whether hierarchical morphological structure plays a role in lexical processing. The performance of a patient who shows sensitivity to the formal complexity of multimorphemic strings was investigated. The patient was tested in a naming latency experiment with affixed nonsense roots that were constructed so the resulting multimorphemic nonword strings were either left-branching, right-branching or morphologically illegal. He showed slower naming responses and more errors for the morphologically illegal stimuli compared to either the left-branching or right-branching legal nonwords. Within the class of morphologically legal nonwords, he showed more difficulty with left-branching structures than with right-branching ones. These results are discussed with reference to models of morphological parsing.