LuCiD Intern Diaries: Investigating the impact British Sign Language has on visual perception.

At the University of Liverpool’s Language Lab under the supervision of Dr Perrine Brusini and Dr Panagiotis Boutris, I had the incredible experience of completing a six-week LuCiD summer internship. I conducted a pilot study for my final-year research project, which is investigating the effect of British Sign Language (BSL) experience on one’s visual perception skills.

This research project has been inspired by the groundbreaking study by Saffran et al. (1996). It demonstrates the ability to segment words in a speech stream can be successfully achieved through a medium of statistical learning, called transitional probabilities. These transitional probabilities are the likelihood of one auditory stimulus following another in a sequence. Saffran et al. (1996) found that children as young as 8 months old can segment target nonsense ‘words’ from ‘non-words’ in a continuous speech stream. Now, how could these transitional probabilities translate into language that doesn’t rely on audio? This is when the investigation into how the perception of ‘visual’ transitional probabilities (vTPs) affects users of BSL. BSL is fully reliant only on visual stimuli, but it is still a language. I aim to conduct a study investigating if BSL users perform better in a task that relies on visual segmentation skills through the use of vTPs than those who do not use sign language. This is the overarching aim for my final-year project, but this internship allowed for a pilot study to be designed, conducted, and analysed before starting the larger project, so modifications can be made.

I had many different responsibilities throughout the internship. To start with, I conducted a thorough literature review of previous research on the topics of BSL, visual segmentation abilities, and language development. By using this knowledge and meetings with my supervisors, we created a methodology that was based on Saffran et al. (1996) but was adapted to be better suited to the task. Once these steps were complete, I submitted an ethics form to the committee so I could conduct the pilot study over the summer period. Once approved, I began preparing the design of the study using a program called Gorilla, something I had never done before. However, under the watchful eyes of my supervisors, I successfully created the task and was ready to release it. I then spent some time advertising and gathering participants, and the experiment was ready to begin! During this entire process, I was also able to assist in the EEG laboratory for postdoctoral research with infants. Once I had achieved the number of participants I was aiming for, I could begin the data analysis process and present my study to the Language Lab.

Upon collecting the data, I was able to learn how to use R Studio to analyse the data with the expert guidance of my advisors. The preliminary results were not significant, which was unfortunate. However, upon reflection with my supervisors, we decided that this was likely due to two factors: the study being underpowered and the task established was too difficult. Despite these results, it has allowed me and the supervisors to adapt the plans once again to make the task easier and incorporate the use of sign language better. This was done by actively using more sign language as stimuli and including different types of sign language, allowing for a wider audience of participants for the final-year project. Altogether, it was such a pleasure to complete this internship. I was able to enhance my research skills which will be critical for research in the future and I could fully immerse myself in the world of research. It was a fantastic opportunity to work with other researchers in the department who have inspired me to continue on this path of researching language development in the future.