Bachelor Thesis from the year 2007 in the subject Psychology - General, grade: 2.1, University of East London, course: BSc Psychology, language: English, abstract: 20 monolingual (Polish) and 20 bilingual (Polish- English) speakers were employed to this study in attempt to establish a set of performance norms for a neuropsychological test battery. Participants were administered a number of cognitive test that resulted in no consistent differences between above language groups. Despite a small sample size, the data obtained could be considered a useful tool for clinicians working with Polish speakers. The second objective was to determine the effect of bilingualism on Verbal Fluency tasks. It was hypothesized that Polish bilinguals would obtain lower scores than Polish monolinguals on above tasks. The groups comprised 40 participants who took part in the first part of the study. They completed 2 letter, 2 semantic and 1 category switching tasks. The analysis of collected data supported the main prediction that there is significant difference between the numbers of words produced by language groups. However the interaction did not reach significance. Further studies are needed in order to facilitate recent findings.