Introduction
In English as a Medium of Instruction (EMI) environments, students must simultaneously process new disciplinary content while operating in a language that may not be their strongest. This dual demand often produces increased linguistic and cognitive load, which can significantly influence comprehension, performance, and classroom participation. For postgraduate TESOL students, understanding and addressing these challenges is essential to ensuring equitable learning experiences for multilingual learners.
Research consistently shows that EMI implementation affects both language proficiency and academic achievement, underscoring the need for integrated teaching that supports content learning alongside language development (Macaro et al., 2017; McKinley & Rose, 2022). However, EMI classrooms often lack adequate language support structures, which can intensify cognitive load—particularly when students are required to navigate discipline-specific terminology in a second language (Si, 2023).
To mitigate these challenges, the involvement of language specialists and the implementation of collaborative instruction models are essential. Studies emphasize that such collaboration can help develop strategic EMI practices that enhance comprehension and foster deeper engagement (Yuan, 2021). Additionally, the integration of language-aware pedagogies strengthens students' capacity to learn both subject content and English simultaneously, resulting in improved academic outcomes (Dafouz & Camacho‐Miñano, 2016).
Addressing linguistic and cognitive load is therefore not simply a matter of adjusting instructional language, but requires ongoing attention to curriculum planning, assessment, and teacher training. Sustained research and reflective practice remain vital for supporting both students and faculty as they navigate the complex realities of EMI learning environments.
Key Concept: Cognitive Load Theory
Cognitive Load Theory (CLT) posits that working memory has a limited capacity. When learners must manage both complex content and a foreign language, their cognitive resources can become overloaded, reducing their ability to store and apply knowledge effectively. In EMI, excessive load can hinder both conceptual understanding and language acquisition.
Types of Cognitive Load in EMI
- Intrinsic Load: The inherent difficulty of the subject matter. For example, scientific terminology or abstract theories can overwhelm learners with limited English proficiency.
- Extraneous Load: Caused by unclear explanations, dense text, or culturally unfamiliar examples. Teachers’ speed, accent, or inconsistent slides can heighten this load.
- Germane Load: The mental effort devoted to schema formation and integration. Effective scaffolding and visual aids can help shift cognitive resources toward this productive load.
Linguistic Challenges and Their Cognitive Effects
EMI students face multiple linguistic barriers—vocabulary limitations, unfamiliar grammatical structures, or low listening fluency—all of which amplify cognitive demands. Learners may rely on translation or context-guessing, diverting mental energy away from content comprehension. This phenomenon, often described as split attention, results in slower processing and increased fatigue during lectures.
Pedagogical Implication
Lecturers should simplify sentence structure, highlight key terminology, and provide multimodal input (visuals, charts, gestures). Encouraging note-taking in both L1 and L2 can reduce mental strain and support deeper understanding.
Managing Cognitive Load: Strategies for EMI Educators
- Use advance organizers—outlines or visual maps to prepare students for complex lectures.
- Segment long lectures into smaller chunks with short pauses or comprehension checks.
- Provide language scaffolds such as glossaries, sentence frames, or bilingual slides.
- Incorporate interactive tasks that promote active learning rather than passive reception.
- Encourage peer collaboration so that students can negotiate meaning together.
Asian EMI Contexts: Cross-Cultural Considerations
In many Asian universities, students often have solid receptive English skills but limited productive fluency. Cultural norms emphasizing teacher authority may further discourage clarification requests. Consequently, cognitive load accumulates silently, resulting in surface learning. Institutions can mitigate this by offering academic English support courses, language clinics, or peer mentoring systems aligned with EMI curricula.
Research Insight
In Southeast Asian English-Medium Instruction (EMI) programs, research shows that when academic discourse diverges from students’ familiar linguistic patterns, the resulting increase in language complexity can impose a substantial cognitive load. This strain particularly affects working memory, making it more challenging for learners to process, retain, and apply new information (Pham et al., 2025; Suoc et al., 2025).
Students often struggle simultaneously with unfamiliar syntax and evolving disciplinary concepts, which can hinder both comprehension and knowledge retention. To reduce this burden, research highlights the usefulness of employing simplified syntax, contextualized examples, and clear discourse organization. These strategies function as effective forms of scaffolding, supporting learners’ cognitive processing and facilitating smoother knowledge transfer (Suoc et al., 2025).
Ultimately, careful attention to language complexity within EMI instruction plays a pivotal role in enhancing student understanding and academic performance. Recognizing and adjusting to learners’ linguistic repertoires allows instructors to balance content mastery with language development, aligning with broader research emphasizing the interdependence of language and learning in multilingual higher education contexts (Vogelzang et al., 2020).
Conclusion
Understanding linguistic and cognitive load in EMI contexts is fundamental for promoting inclusive education. Postgraduate TESOL educators must learn to recognize when language becomes a barrier and employ strategies that balance intellectual rigor with accessibility. Effective EMI teaching does not merely transmit knowledge in English—it builds bridges between language, cognition, and learning.