This study aims to find out the relationship between Working Memory Capacity and Verbal and Mathematical Achievement. The participants were 60 students at Hacettepe University School of Foreign Languages Department of Basic English. For measuring working memory capacity, one simple (Digit Span Task) and one complex (Reading Span Task) were used. Verbal achievement of the participants was measured both in their native language (Turkish) and their foreign language (English). For measuring their native language achievement, the participants&rsquo / Turkish scores in Y&uuml / ksek&ouml / gretime Ge&ccedil / is Sinavi 2010 (Transition to Higher Education Examination) / and for measuring their foreign language achievement, the participants&rsquo / scores in Hacettepe University School of Foreign Languages Department of Basic English Elementary Groups Achievement Exams I and II were used. For measuring their mathematical achievement, the participants&rsquo / Mathematic scores in Y&uuml / ksek&ouml / gretime Ge&ccedil / is Sinavi 2010 (Transition to Higher Education Examination) were used. The data was analyzed using a statistical package program (SPSS Version 18.0). The data analysis results revealed that there is a relationship between working memory capacity and verbal and mathematical achievements of the participants. It was tentatively concluded that, as the working memory capacity of the participants increase, so might their achievement in verbal and mathematical subjects. This result was discussed in terms of its implications, which may be that, if working memory capacity could be improved / the cognitive processes which the working memory is responsible for might also improve.

In this thesis, the relationship between cognition and speech-in-noise recognition, in normally-hearing Swedish students, is examined. The Trail Making Test, hypothesized to measure a wide range of cognitive functions, including executive function and working memory, has been criticized for being a culturally biased measure, hence the need for a culturally unbiased version. A between-group experiment was conducted in which a non-semantically dependent version of the Trail Making Test was compared to the original Trail Making Test in order to test for psychometric equivalence. A total of 21 young normally-hearing Swedish students were given three tests: TMT or TMT (non-semantically dependent version), a Swedish Reading Span Task and a Swedish speech-in-noise recognition task. The B parts of the two Trail Making Test versions differed significantly and both were moderately to highly correlated to speech-in-noise and reading span performance. The results indicates that the original Trail Making Test is a more plausible index for executive function and strengthens the relationship between executive function, working memory and speech-in-noise recognition.