Exploring knowledge of semantic categories in Persian deaf students

The present study explores the knowledge of semantic categorisation in 24 students with hearing loss who learned spoken Persian at school and a matched number of hearing students. Since the deaf participants learned no official sign language from family or at school, we designed three types of tasks, namely pictorial, written, and entailment which were all based on spoken Persian. Results indicated a large gap between the deaf and the hearing group in all three tasks. A within-group analysis showed that the deaf group performed best on entailment and pictorial tasks compared to written tasks. It was also interesting that the deaf participants did far worse on questions requiring them to supply a word than when they had to mame a choice. The fact that several students demonstrated a close to normal performance on part of the stimuli which involved choices rather than naming tasks indicates that the gap between deaf and hearing students is not so much due to inability to recognise semantic relations and categories but due to the skill at using their knowledge actively.