This study examines the effect of irrelevant speech effect on a serial recall task, focusing on individual difference indexes, such as introversion/extraversion, field dependence/independence, and reading span. A foreign language (Spanish) and pink noise were used as auditory distractor stimuli. The results demonstrate that the irrelevant speech effect is robust and causes a fixed increase in the number of serial recall errors, irrespective of the individual difference indexes, such as introversion/extraversion, field dependence/independence. On the other hand, the serial recall performance itself was related to both introversion/extraversion and field dependence/independence. The results are interpreted as suggesting that while the irrelevant speech effect mainly reflects the functioning of phonological loop, the performance of serial recall may depend more on the functioning of the central executive, which may differ between introverts and extraverts and between field dependents and field independents. Further examination from this perspective may serve to clarify the mechanism by which the irrelevant speech effect occurs and its relation to the individual differences of performance in various cognitive tasks.

Key words: irrelevant speech effect, individual differences, introversion/extraversion, field dependence/field independence, working memory