Keynote speakers

Prof. Mathieu Declerck 
(Vrije Universiteit Brussel, Belgium)

Keeping multilingual learning under control

During multilingual language processing, both languages are activated to some degree and compete with each other. Language control is the process used to minimize this cross-language interference and select words in the appropriate language. The vast majority of language control studies have focused on investigating language control during language production and comprehension. In this talk, I will discuss the influence of language control from a different perspective by focusing on its impact on second language acquisition and content learning. More specifically, I will discuss recent language switching studies that investigated vocabulary and rule learning of a second language with adult monolinguals, and language mixing experiments on content recall with children in a bilingual education program. Together, these results indicate that language control does not just influence language production, and language comprehension somewhat, but can also influence learning.

Dr. Alice Foucart 
(Universidad Nebrija, Madrid, Spain)

Emotion processing in multilingual contexts:
Behavioural and neurophysiological evidence

Emotion plays a crucial role in social interaction, enabling individuals to communicate their feelings and interpret the emotional states of others. Although certain forms of emotional expression, such as facial expressions, appear to be universal, expressing emotions through language may come with certain limitations. Research has shown that responses to emotionally charged stimuli tend to be weaker when processed in a second language (L2) compared to a first language (L1). In this talk, I will present behavioural and neurophysiological evidence investigating this phenomenon. First, I will examine the features that determine the emotionality of affective words. Then I will report studies that have examined emotion processing in sentence context. I will also discuss the cognitive implications of reduced emotional reactivity in L2. Finally, I will consider native speakers’ responses to affective stimuli produced by non-native speakers, offering a broader perspective on emotion processing in multilingual communication.

Dr. Miguel Angel Santos Santos 
(Unidad de Memoria Sant Pau, Barcelona, Spain)

Bilingualism and Neurodegenerative Disease:
From Molecular Mechanisms to Clinical Management

Bilingualism has been proposed as a modifiable factor that delays dementia onset by approximately four years. Yet despite half the world's population being bilingual, critical gaps persist: most studies lack biomarker-confirmed diagnoses, define bilingualism dichotomously, and focus almost exclusively on typical Alzheimer's disease in English speakers. The biological mechanisms underlying bilingualism's protective effects remain largely unknown.

This presentation addresses these gaps through two comprehensive research programs being carried out at the Hospital Sant Pau Memory Unit in Barcelona. First, we present findings from our Alzheimer's Association-funded study examining the molecular bases of bilingualism's protective effect in a Spanish-Catalan bilingual cohort with CSF biomarkers of amyloidosis, tau, and neuroinflammation. Our results demonstrate that active bilinguals show enhanced cognition across multiple domains while also exhibiting interactions between bilingualism, sex, and education on amyloid and neuroinflammation markers, suggesting both resistance (reduced pathology) and resilience (preserved function despite pathology) mechanisms operate simultaneously.

Second, we present data from our NIH-funded international collaboration with the University of Texas examining how bilingualism affects diagnosis and treatment in primary progressive aphasia, a neurodegenerative syndrome characterized by predominant language impairment. We demonstrate that automated NLP-based analysis of bilingual connected speech achieves high accuracy in differentiating PPA variants in bilinguals, and that tailored bilingual speech-language interventions produce significant improvements maintained at one-year follow-up with cross-linguistic transfer.

These findings carry immediate clinical implications for risk assessment, diagnosis, and treatment of bilingual patients with neurodegenerative disease, while highlighting the urgent need to capture multilingual language use data along with other lifestyle and sociocultural factors in aging cohorts to understand how their interactions shape bilingualism's protective potential.