Undergraduate student UT-Austin rowlett, Texas, United States
Abstract: Twenty-five Greek-English young adult bilinguals performed three semantic (animals, foods, clothes) and three letter (English: F, A, S; Greek: Χ, Α, Σ) fluency tasks in each language. Results will be discussed regarding within- (i.e., semantic vs. letter) and between-language (i.e., Greek vs. English) performance differences.
Description:
Introduction: Verbal fluency (i.e., generative naming) tasks have been widely used as part of a neuropsychological assessment as they quickly screen for cognitive and language disorders (e.g., Gollan et al., 2002). In a typical verbal fluency task, participants are given 60 seconds to list as many exemplars as possible in a given semantic (e.g., animals) and/or letter (e.g., words that begin with F) category. Both tasks rely on language ability (e.g., integrity of semantic lexical networks) and executive functions (e.g., lexical retrieval, organization of lexical search, inhibition, self-monitoring etc.) (Henry & Crawford, 2004). Despite its wide use with several clinical populations, little is known on how to interpret performance in the task in bilingual speakers. Unfortunately, when assessing cognitive and linguistic ability in bilingual speakers, clinicians often compare their performance to monolingual norms without taking into consideration the individual’s bilingual profile. Age of acquisition, use and proficiency of each language are all factors that may affect the individual’s test performance (e.g., Munoz & Marquardt, 2003; Roberts et al., 2002); therefore, misinterpretation of test results and possible inappropriate treatment recommendations are not uncommon when working with bilingual speakers. Evidence thus far suggests a bilingual disadvantage in the verbal fluency task (e.g., Gollan et al., 2002; Roselli et al., 2000); however, the mechanisms of this disadvantage remain unclear. One possibility is that bilingual speakers need to inhibit unintended activated exemplars from the non-target language, which in turn may lead to more errors and/or delay the retrieval of exemplars from the target language resulting in fewer accurate responses compared to monolinguals (e.g., Sandoval et al., 2010). Alternatively, reduced vocabulary size in each language, as opposed to combining vocabulary in both languages, may offer fewer options when each language is tested separately in bilingual speakers, as they access only part of their entire conceptual vocabulary (e.g., Bialystok et al., 2008). The present study investigated lexical access in Greek-English bilingual young adults via a series of category and letter verbal fluency tasks.
Method: Twenty-five Greek-English bilinguals, ages 21-48 years (M= 30.6 yrs , SD= 7.2 yrs; n= 6 females, n= 19 males) performed a verbal fluency task in Greek and English. All participants completed a detailed case history form in order to provide demographic information as well as their health history. In order to be included in the study, participants were required to report no history of any speech/language/learning or neurological diagnoses and performed within one standard deviation in the Test of Nonverbal Intelligence 4th Edition (TONI-4, Brown et al., 2010). In order to determine each participants’ bilingual status, participants filled out the Bilingual Language Profile (BLP, Birdsong et al., 2012). The BLP includes the following four sections: a) Language history, which includes questions regarding the participants’ first exposure of each language, years lived in a country/region where each language is spoken etc., b) Language use, which includes information about the percentage of use of each language on a weekly basis in several contexts (e.g., with friends, at work etc.), c) Language proficiency, which includes a 0-6 self-rating scale, 0= not well at all and 6= very well, and participants were asked to rate their perceived proficiency of each language in the areas of speaking, understanding, reading and writing, and d) Language attitudes, which includes a 0-6 self-rating scale, 0= disagree and 6= agree, and participants were asked to answer questions regarding how much they feel like themselves speaking each language, how important it is for them to use each language like a native speaker etc. Each section results in a weighted score within and across languages. Participants in the study performed 12 verbal fluency tasks, six in each language. The semantic fluency tasks in each language included the categories animals, foods, and clothes and the letter fluency tasks included the letters F,A,S in English and Χ, Α, Σ in Greek. Participants were given 60 seconds to name as many exemplars in each category as possible. The total number of accurate words generated on each task, the mean cluster size and the number of switches we collected. Clustering refers to the presence of words within a semantic or a phonemic subcategory (Troyer et al., 1997). For example, the words dog-cat-pig, all are farm animals; thus, they make one cluster. Phonemic clusters were defined as successively generated words that began with the same first two letters, rhymed, differed only by one vowel sound, or were homonyms. The mean cluster size was obtained by summing all the cluster sizes and dividing by the sum of all clusters in each fluency task in each language. Lastly, the number of switches for each fluency task was also collected. Switching is the ability to shift efficiently to a new subcategory/cluster when a current category is exhausted (Troyer et al., 1997). Switches were calculated as the number of transitions between clusters.
Results: Data have been collected and participant responses have been transcribed in each language. Cluster coding is currently ongoing and will be completed by the end of the summer. The number of accurate words, the mean cluster size, and the number of switches will be compared between the two verbal fluency tasks within each language (i.e., semantic vs. letter) as well as between languages. In addition, several bilingualism factors, such as age of second language exposure/acquisition, current language use, language proficiency, language dominance etc., will be extracted and added as variables in order to investigate which bilingualism factors primarily affect task performance.
Presentation Format & Methods: interactive poster presentation, questions & answers
Supporting Research: Reference 1: Gollan, T., Montoya, R., & Werner, G. (2002). Semantic and letter fluency in Spanish- English bilinguals. Neuropsychology, 16(4), 562-576.
Supporting Research: Reference 2: Rosselli, M., Ardilla, A., Arujo, K., Weekes, V. A., Caracciolo, V., Padilla, M. & Ostrosky- Solis, F. (2000). Verbal fluency and repetition skills in healthy older Spanish– English bilinguals. Applied Neuropsychology, 7, 17–24.
Supporting Research: Reference 3: Sandoval, T., Gollan, T., Ferreira, V., & Salmon, D. (2010). What causes the bilingual disadvantage in verbal fluency? The dual-task analogy. Bilingualism: Language and Cognition, 13(2), 231-252.
Supporting Research: Reference 4: Henry, J.D., & Crawford, J.R. (2004). A meta-analytic review of verbal fluency performance in patients with traumatic brain injury. Neuropsychology, 18, 621- 628.
Supporting Research: Reference 5: Bialystok, E., Craik, F. I. M. & Luk, G. (2008). Lexical access in bilinguals: Effects of vocabulary size and executive control. Journal of Neurolinguistics, 21, 522–528.
Learning Objectives:
Describe the processes involved in a verbal fluency task
Explain the bilingual disadvantage in a verbal fluency task
Discuss the clinical implications of the use of a verbal fluency task in bilingual speakers