Main author: Kathryn Crowe
Institution or Company: Department of Speech-Language Pathology, School of Education / School of Health Sciences, University of Iceland
Co-Authors, Institution or Company:
Ömer Dağlar Tanrıkulu, Department of Psychology, School of Health Sciences, University of Iceland.
Introduction: Semantic categorization in deaf and hard-of-hearing (DHH) students has been examined by measuring preferential cognitive processing of words that are more/less characteristic of a semantic category (lexical typicality). Previous studies of lexical typicality in DHH students have used stimuli that conflate word typicality with word frequency, greatly disadvantaging DHH students who, on average, have smaller vocabularies. This study examined typicality effects using a new stimuli set without this bias.
Method: Participants were 90 students enrolled at an American college (46 DHH, 44 Hearing). In this reaction timed task, participants were shown a stimulus words on a screen and asked whether the word belonged to the displayed category. Each category contained: five central category member words, ten borderline category member words, and five non-category words. Participants also undertook a receptive vocabulary assessment.
Results: Preliminary analysis of results indicates that both DHH and hearing students exhibited lexical typicality effects with judgements about category membership made most quickly for central words, followed by non-member and then borderline words. DHH and hearing students performed similarly in terms of the accuracy of their judgements, but hearing students made judgements faster than DHH students across all member types. Despite all words in the stimulus list being frequently occurring words, a trend was identified in which larger receptive vocabularies were associated with faster reaction times.
Conclusions: Preliminary analyses provide evidence for lexical typicality effect differences between DHH and hearing students existing in spite of use of stimuli that removed the confounding variable of word frequency effects.