Learn about the PhD topics undertaken by our Doctoral Candidates (DCs).
A foreign accent immediately reveals the speaker’s identity, which can affect the way the information coming from this speaker is processed. Using electroencephalography, the project will examine how individual factors (e.g., speaker’s accent strength, stereotypes associated to nationalities, native listeners’ cognitive flexibility) affect the way the brain processes foreign-accented speech and the consequences this may have on social interaction and cognitive processes (e.g., decision making).
Previous research has repeatedly shown that the speaker’s voice or accent can influence word processing in various ways. For instance, words spoken by the same voice are better encoded and recognised. Additionally, a speaker’s voice or accent can be used proactively to predict forthcoming words. This research project aims to explore whether social and individual characteristics derived from speech, such as accent, language, and voice (often stereotype-mediated), are used to predict upcoming words. Several EEG measures will be employed to investigate the timing and neural underpinnings of interactions between speaker identity and predictive processes.
While exposure to linguistic diversity in early childhood has been associated with delayed word recognition and word comprehension; other research provides evidence for benefits of early exposure to accented speech. The current project examines the effects of regional vs. foreign-accented exposure in early childhood on the development of lexical representations and cognitive skills. The project will examine, via eye-tracking, the mechanisms and dynamics of accented speech processing, focusing on the potential cognitive costs associated with accent adaptation and accent switches.
Understanding foreign-accented speech may become more challenging with age, primarily due to cognitive, sensory, and linguistic changes. While sensory changes associated with aging have been consistently observed in older adults, the impact of cognitive decline is less well-explored. This project aims to investigate how the decline in cognitive and linguistic functions in older adults affects their comprehension of foreign-accented speech. At the cognitive level, the study will explore the roles of cognitive control deficits (e.g., working memory and inhibitory control), while at the linguistic level, it will examine lexical representations, speech processing and integration in older adults compared to younger adults using eye-tracking.
In today’s globalised world, exposure to foreign-accented speech is a central feature of communication. Research has shown that the characteristics of the speaker can significantly influence how language is processed. In this project, participants will listen to speech produced by avatars with either a foreign or native accent in a virtual reality environment, while their eye movements are tracked. This approach offers both high ecological validity and robust experimental control, allowing for the simulation of the complexity and dynamics typical of everyday listening situations.
Accents play a crucial role in social interactions, affecting not only language comprehension but also social inferences and cognitive processing. While much research has focused on how foreign accents are perceived and processed by listeners, the underlying neural mechanisms, especially during naturalistic interactions, are not well understood. This project aims to explore how accents are processed in real-time social exchanges by using EEG measures of neural synchronisation and functional near-infrared spectroscopy (fNIRS) to monitor neural activity in the prefrontal and temporal regions. The goal is to identify neural correlates of accent comprehension and adaptation and understand how individual differences in cognitive flexibility and social awareness affect accent processing.
Accent is an important design cue within human-conversational AI dialogue, especially with speech only conversational agents, where it impacts inferences of conversational AI’s capability as a dialogue partner (termed partner models), along with levels of audience design and adaptation in human-AI language production. Current voice design leads to significant overestimation of the capabilities of such systems, leading to poor partner modelling of the actual capabilities of the system affecting interaction. This PhD project aims to investigate 1) how the use of foreign accented speech by conversational AI agents can be used as a way to influence user partner models; 2) how this impacts informativity in language production during human-conversational AI dialogue and 3) how these effects are influenced by the group structure (e.g., dialogue vs multiparty) and collaborative task.
Foreign accent originates in the influence of the phonology and orthography of the native language on foreign language production. Although a lot is known about the origins of foreign accents, the very large variability in foreign accent markers and strength across individuals has been very little studied. Yet, exploring individual variability is fundamental to our understanding of the origins of foreign accentedness and effective tools to improve speakers’ pronunciation This project aims to identify the key factors that cause foreign accents and create targeted training programs to improve foreign speech sound production in a personalised way.
Listeners’ understanding of speech improves over time when exposed to accented speech. This phenomenon of adaptation has been well-documented in behavioural studies. However, the neural mechanisms underlying this adaptation, particularly in naturalistic settings involving continuous speech, remain poorly understood. This project aims to investigate these mechanisms using MEG and behavioural measures. Specifically, the study will assess whether neural tracking of multiple features of the accented speech shows evidence of adaptation within individual speakers and across different speakers with varying accents.
In dialogue, speakers tend to converge on the words they use. Dialogue thus constitutes an ideal setting to integrate new words and new uses for known words into long-term memory. However, it is unknown whether imitative behaviours occurring during dialogue may be the source of changing in linguistic representations after dialogue. Using electrophysiological and behavioural measures, the project will address whether and how the interaction between a native speaker and a non-native speaker changes linguistic representations at phonological and lexical levels, leading to improvements in speech perception and production.
Speakers tend to align to the lexical choices of their interlocutors (i.e., repeat the same word as previously used by the interlocutors), a term referred to as lexical alignment. While alignment is argued to contribute to mutual understanding and ultimately to successful communication in native-native interactions, it is relatively unknown how interactions involving a non-native speaker may influence lexical alignment. Using behavioural and EEG methodologies, we will investigate whether social factors (e.g., negative/positive stereotypes conveyed by a foreign accent) reduce/increase native speakers’ willingness to align to foreign interlocutors. We will also examine whether reduced alignment may be due to native speakers’ willingness to help foreign speakers improve their lexical knowledge. The findings will shed light on the social and individual factors (e.g., empathy, cognitive flexibility) that influence social interactions.
Foreign-accented speech leads to the categorisation of the speaker as an outgroup individual in terms of cultural and social heritage. At the same time, foreign-accented speech deviates from the listener’s standard pronunciation and can be more challenging to understand. Based on the hypothesis that social categorisation and language processing influence cognition, this project will investigate how foreign-accented speech impacts performance in tasks involving thinking, judgment, and decision-making, compared to native-accented speech. To accomplish this, the project will leverage wellknown cognitive biases (e.g., causality bias, repetition-truth effect, endowment effect) and decision-making frameworks (e.g., ultimatum game) to explore how information delivered in foreign- or native-accented speech affects cognition.
Studies have shown that foreign accents affect a speaker’s inferred knowledge of credibility. But we have little information about the cognitive processes and reasoning mechanisms that lead to this outcome (e.g., whether individual accent features activate fast stereotypical categorisations or whether judgments emerge cumulatively over time) or of the individual and contextual factors that moderate it (e.g., listener background and prior exposure, social setting). The goal of this project is to address these issues by examining inferred credibility of foreign accents in a courtroom setting. Using virtual reality to elicit attitudinal responses within information-rich contexts, the project will identify how social and rolelinked stereotypes interact with individual listener factors to constrain how foreign accents are evaluated.
Bridging Communication Gaps in Human and Human-AI Interactions: The Role of Accented Speech on Neurocognitive mechanisms and Social Dynamics