Note: This blog post was also published at Swansea University's English Language and TESOL blog and the Welsh Graduate School of Social Science blog. This trip was funded by the Welsh Graduate School of Social Science.

As is often the case in research, my discovery of pupillometry was not the result of a deliberate plan, but rather a fortunate accident. In 2024, while pursuing my master’s degree in Social Research Methods, I attended the EuroSLA conference – the European Second Language Acquisition Researchers’ Conference – held at the University of Montpellier. There, alongside my prospective PhD supervisor, Dr Vivienne Rogers, I attended a wide range of presentations focussed on second language acquisition. 

EuroSLA was my not my first experience of an academic conference. Early that year, I had helped run the International Symposium on Bilingual and L2 Processing in Adults and Children (ISBPAC) when it was hosted in Swansea. Even so, it was at EuroSLA that I began to appreciate the true value of such events. Conferences, I realised, offer far more than just formal talks: they provide spaces for intellectual exploration, unexpected inspiration, and informal conversations that often prove just as influential as the scheduled presentations. 

It was during one such presentation – delivered by Dr Dieter Thoma and Miss Stefanie Radetzky – that I first encountered the pupillometry. At the time, the method was entirely new to me. I left the presentation intrigued, my curiosity piqued, and with a question that would come into my PhD: what might pupillometry reveal about how learners process and respond to language?

What is Pupillometry?

Before I go any further, it might be useful to briefly explain what pupillometry is. Pupillometry is the measurement of pupil size and reactivity, typically recorded using eye-tracking equipment. Though it may seem surprising at first, our pupils do more than respond to changes in light – they also dilate and constrict in response to emotional and cognitive stimuli. This makes them a subtle but revealing physiological marker of internal processes such as mental effort, attention, and arousal. In the context of second language acquisition, pupillometry opens up a promising avenue for investigating how language learners process emotional content, offering insights that are often inaccessible through behavioural measures alone.

Following the presentation, I found myself increasingly intrigued by the possibilities this method might offer. I began to wonder whether pupillometry could be applied beyond its original context, particularly in research concerning language attitudes and implicit evaluation. Over time, this curiosity evolved into a line of enquiry within my own doctoral research.

The Opportunity to Train in Mannheim

A few months later, while discussing my early ideas with Dr Rogers, she suggested I get in touch with Dr Thoma to explore the method more seriously. I reached out to him by email, and to my delight, he responded warmly. After a brief exchange – and with the support of both Dr Thoma and Stefanie – I was invited to visit the University of Mannheim. There, I would receive hands-on training in pupillometry and have the chance to present my research at their departmental colloquium. 

This visit proved to be a turning point. The training I received – both technical and conceptual – deepened my understanding of pupillometric methods and helped me think more critically about how they might be adapted for my own research questions. Presenting my ideas to a new academic audience also gave me the chance to clarify my thinking and situate my work within a wider research community.

This kind of opportunity – especially at such an early stage of a PhD – was only possible because of the support of the ESRC. I was fortunate to be able to draw on the travel fund attached to my studentship, which covered the costs of travel and accommodation. Access to this kind of funding is something I do not take for granted. It allowed me to pursue a line of enquiry that would otherwise have remained abstract, and to build valuable connections that have shaped both my confidence and my research direction. It also reminded me how vital it is that early-career researchers are given the resources to explore, experiment, and collaborate beyond their home institutions.

Presenting in Mannheim

Of course, the idea of presenting my research at Mannheim’s departmental colloquium was nerve-wracking. As someone still early in their doctoral journey, the prospect of sharing still developing ideas with a room of experienced academics was daunting. But once I began speaking, I found myself enjoying the challenge. I spoke about the roots of my research focus: language revitalisation in Wales, specifically among young people. My interest in this area is shaped not just by academic curiosity, but by experience. Before beginning my postgraduate studies, I trained as a primary school teacher. That time in the classroom gave me a first-hand view of how children engage with the Welsh language – not just how they use it, but how they feel about it. I became increasingly fascinated by the emotional, social, and identity-related dimensions of language learning, particularly in a context where the language carries historical, cultural, and political weight.

I also spoke about my master’s research, which explored the dynamics of post-education Welsh language decline among English-medium educated young adults. Motivated by a gap in the literature, I used a mixed-methods approach combining the Bilingual Language Profile (BLP), an Implicit Association Test (IAT), and stimulated recall interviews. This allowed me to investigate both explicit and implicit attitudes towards Welsh and English, as well as the participants’ broader language experiences. While quantitative data revealed differences in language dominance between those who continued learning Welsh beyond school and those who did not, it also showed that implicit attitudes remained largely stable across both groups. In contrast, qualitative findings highlighted complex factors influencing disengagement from Welsh, including linguistic insecurity, cultural dislocation, and the perceived lack of opportunities to use the language. The study underscored the emotional and social dimensions of language decline –  aspects that traditional measures often overlook – and laid the groundwork for my current interest in how less overt responses to language, such as unconscious effort or emotional arousal, might be captured through physiological methods like pupillometry. 

The feedback I received was generous, constructive, and thought-provoking, and the atmosphere in the room was one of genuine intellectual curiosity. Several attendees offered new perspectives, challenged my assumptions in useful ways, and shared examples from their own research that resonated with mine. I left the session not only with a clearer sense of where my project was heading, but also with a deeper appreciation for the collaborative, international nature of academic work.

Exploring Mannheim: Ice Cream and Architecture

Beyond the academic programme, my time in Mannheim was also personally enriching. I had the chance to explore some of the city’s landmarks, including the iconic Wasserturm and the grand Jesuitenkirche Basilica Carolina, whose ornate baroque interior offered a moment of quiet reflection amid a busy schedule. I also tried Spaghettieis for the first time—a dessert made to resemble a plate of spaghetti, which ended up being one of the highlights of the trip. These moments reminded me of how valuable it is to experience a place beyond the university walls. They grounded the visit in memory and made the whole trip feel like more than just work – it was a genuinely enjoyable and formative experience.

I’ve only just returned from Mannheim, but already the experience has begun to shape how I think about my project. While I’m still in the early stages of refining my study design, the training provided a strong foundation – both technical and conceptual – for potentially working with pupillometry. I now have a clearer sense of how the method works in practice: how to calibrate the eye-tracking equipment, how to structure stimuli presentation, and how to begin approaching data analysis. More importantly, the conversations I had during my visit helped me think critically about the kind of questions pupillometry can help answer – and just as crucially, the questions it cannot.

Pupillometry and Language Attitudes: Where Next?

As I begin to sketch out how pupillometry might be incorporated into my doctoral research, I’m particularly interested in how it can be used to investigate implicit emotional responses to different language varieties. My research focuses on language attitudes, and I’m curious about whether pupil dilation might offer a window into how listeners respond to languages or accents they have been socialised to admire, dismiss, or fear. It’s early days, and many challenges lie ahead, but the experience in Mannheim has given me both the tools and the confidence to pursue this line of enquiry.

For other early-career researchers, especially those just beginning their PhDs, my advice is simple: follow your curiosity — but anchor it to your research problem. It's tempting to chase every exciting new idea, but the most rewarding explorations are those that deepen or enrich your central questions. If you’re lucky enough to have access to training funds or supportive supervisors, take the leap: reach out to people whose work excites you, attend conferences that broaden your perspective, and don’t be afraid to explore unfamiliar methods. These pushes beyond your original plan are most valuable when they help you see your project from a new angle or give you tools to approach your core problem differently. You never know which talk, conversation, or unexpected opportunity might quietly reshape the direction of your research.

Want to know more?

Follow this link to find the university's website: University of Mannheim | University of Mannheim 

Follow this link to find the department's current project and publications, including eye-tracking and pupillometry research: Research | School of Humanities | University of Mannheim