Lexical access in brain-damaged individuals: Evidence from anomic aphasia

Abstract

Facilitation and inhibition are the two mechanisms of lexical activation. If one word in the lexical facilitates the activation of the other word, it is termed facilitation. On the other hand, if one word/lexical item impedes the activation of the other word in the lexicon, it is called inhibition. Many experimental tasks like naming and priming tasks can be used to tap these two mechanisms of lexical activation. The current study aimed to test these two patterns of lexical activation in persons with anomic aphasia. Ten persons with anomic aphasia and ten neurologically healthy individuals designated as group 1 and group 2 served as participants. The blocked naming task was administered to the participants. The semantically related blocks comprised pictures belonging to the same lexical category, while semantically unrelated blocks comprised pictures belonging to different lexical categories. For group 1, vocal reaction time and accuracy scores were better for unrelated blocks than related ones. For group 2, there was no evident difference between the vocal reaction time and accuracy scores for related and unrelated blocks. The difference between the vocal reaction time for semantically related and unrelated blocks was significant statistically only for group 1, indicating that the mechanism of lexical activation was different for the two groups. Better vocal reaction time for unrelated blocks indicated inhibition in persons with anomic aphasia.