Automatic Mechanism of Lexical Retrieval in Persons with Broca’s Aphasia

Abstract

Word finding difficulty is the most common linguistic deficit seen in aphasics. Researchers have attributed word finding difficulty to degradation of lexical items in the lexicon or lexical retrieval deficits. Lexical retrieval deficits can be explored by employing semantic paradigm. Two mechanisms of lexical retrieval namely automatic and volitional mechanism of lexical retrieval have been identified. Several researchers have postulated that the automatic mechanism of lexical retrieval is defective in persons with Broca’s aphasia, while some researchers contradict the claim. The present study was carried out with the aim of exploring automatic mechanism of lexical retrieval. Six persons with Broca’s aphasia were considered for the study. Lexical decision task was administered on all the six participants. Stimulus for the lexical decision task comprised of semantically related and unrelated word pairs. The accuracy scores on semantically related and unrelated word pairs were computed separately. Accuracy scores were better for semantically related words (74%) compared to semantically unrelated scores (62%). Further the accuracy scores were compared by employing Wilcoxon’s signed rank test. The Z score obtained (4.14) showed significant difference between the semantically related and unrelated words showing that priming was operational and the automatic mechanism of lexical retrieval was likely intact.