فاطمه نعمتی

Semantic categorization is a procedure that involves grouping words or concepts based on their meaning and the way they are associated with each other. By understanding how different words are related to each other through their shared semantic categories, learners in EFL classrooms can better remember new words and use them appropriately in context. Despite previous research indicating that time constraints can influence learners' semantic categorization ability, there is a lack of investigation into whether manipulating these factors, alongside individual differences such as working memory, can aid EFL learners. This thesis therefore aimed to investigate how time pressure and working memory might impact the semantic categorization ability of Iranian EFL learners with different levels of English proficiency by recording EEG data, namely, P3 and ERN components of ERPs. In this thesis, 42 EFL learners were invited to participate in a Go/No-Go experiment while an EEG device recorded their neural activity. Linear mixed-effects modeling was employed to analyze the mean amplitudes of the ERP components. The results were in favor of the no time pressure condition indicating that time pressure significantly reduces the negativity of ERN and the positivity of P3. Moreover, the learners’ working memory capacity was found to have a significant effect on P3, emphasizing its role in their semantic categorization performance. The findings of this thesis benefits Iranian EFL instructors and learners by underscoring the significant influence of time pressure and working memory on semantic categorization, proving the importance of providing targeted strategies to reduce the anxiety that comes with learning vocabulary under time pressure and to take into account the individual differences in their working memory capacity.