Serial order and item memory in mono- and bilinguals

Abstract

Our aim was to investigate serial order and item memory in mono- and bilingual language processing. Hypotheses were that 1) memory for serial order would activate specific brain regions and therefore can be seen as an independent part of short term memory and 2) bilinguals rely more on serial memory as language consists of phonological sequences and language specific grammatical word order. Serial order and item memory were compared using data from behavioral and EEG methods. Fifty participants (25monolingual, 25 bilingual) were tested and bilingual language proficiency was assessed using a battery of tests. Behavioral responses and EEG was recorded from a 128 electrode EEG net continuously sampled at AD rate 1000 Hz/channel. Inter-electrode impedance was maintained below 50kOhm. EEG and EOG were amplified offline using a .05 – 30Hz band-pass filter. Trials with EOG artifacts exceeding the range of +/-150 µV were excluded, and the remaining trials were baseline corrected, average re-referenced and averaged for each condition separately across participants. We identified independent ERP components associated with serial order and item memory and showed significant differences between mono- and bilingual speakers. Our data support previous findings that memory for serial order is an important predictor of language processing.