The effects of second-language acquisition on verbal fluency among elderly Israelis

The present study investigated the effect of age of second-language acquisition (Hebrew) on verbal fluency in a random sample of 196 elderly Israelis from four distinct ethnic groups. Using conventional statistics, it was shown that phonemic fluency, particularly switching, is associated with education and the age of Hebrew acquisition, while semantic fluency, particularly clustering, is associated with age. Ethnic differences were not significant after controlling for the age of Hebrew acquisition and education. Additional analyses show that the tendency of subjects to use borrowed, non-Hebrew words on the phonemic fluency task was associated with lower total scores on this task and later age of Hebrew acquisition. In contrast, the tendency to use non-Hebrew words on the semantic fluency task was associated with age and higher total scores. These findings are discussed with regard to recent functional imaging studies of bilingual subjects. Such findings indicate that native and second languages form distinct areas of activation in the dominant anterior language area, an area often associated with phonemic processing and switching, whereas an overlap of activation of various languages has been demonstrated within the posterior language areas, those that are often associated with semantic processing.