Is Semantics Affected by Missing a Critical Period? Evidence from the Persian Deaf

The present study aims to explore the semantic knowledge of a group of Iranian deaf individuals who, due mainly to auditory deprivation did not acquire language normally in early years of their life. The participants were ten deaf and a matched number of hearing individuals as control group. A test of five tasks was administrated to assess their knowledge of vocabulary, collocation, semantic categorizations, semantic features, and proverbs. Although the results indicated a significant difference between the deaf and the hearing group, a between- group comparison of each task revealed no significant difference between the deaf and hearing participants in the number of errors in vocabulary, collocations, semantic categorization, and semantic features. The only task in which deaf participants did significantly worse than the control group was that of proverbs. Therefore, it could be argued that, language deprivation in early childhood does not have the same effect on different components of our linguistic knowledge and that the acquisition of semantics may well continue beyond puberty.