Ageing and sentence processing

The focus of my PhD research is the effect of old age on sentence production. Some aspects of language processing seem to be more negatively affected by ageing that others and I am interested in whether the way we plan and produce sentences changes with old age. To examine this, I have conducted multiple studies in which I measure speech onset latencies in young and older adults when producing different sentence types: the time a speaker takes to begin sentence is informative about underlying sentence planning processes. In this study, we found that while syntactic planning scope appears to be relatively unaffected by old age, there is an age-related decline in the integration of lexical items into syntactic structures.

Collaborators: Katrien Segaert, Linda Wheeldon

Syntactic priming across the lifespan

Syntactic priming is a behavioural phenomenon by which speakers are more likely to repeat a syntactic, or grammatical, structure if they have recently processed a sentence of the same structure. The magnitude of syntactic priming can be used to gain insight into nature of a speaker’s linguistic representations. We are using this technique to examine syntactic representations in young children, whose language skills are still developing, and older adults, who are experienced language users but who may be experiencing changes in way syntax is represented within the lexicon. In this study, we found that syntactic priming and the related phenomenon of lexical boost (repetition of verb enhances the priming effect) were preserved in old age. In this study, we found that both young and older adults' syntactic choices were determined by repetition of global, not internal, syntactic structure.

Collaborators:  Katherine Messenger, Elizabeth Maylor, Katrien Segaert, Linda Wheeldon 

Neural processes involved in syntactic binding

Successful language processing involves the binding of multiple words into larger syntactic structures (or sentences) with more complex meaning. This is essential to the expressive power of human language, and we are interested in the neural processes that support syntactic binding. To examine this, we are conducting a studying using magnetoencephalography (MEG) in which we measure participants' neural responses (specifically, the magnetic fields produced by electric signals in the brain) when processing different types of sentences. We have pre-registered this study on the Open Science Framework (OSF); it is currently embargoed.

Collaborators: Katrien Segaert, Ali Mazaheri, Ole Jensen

Sentence planning in bilingual speakers

When a bilingual speaker produces a sentence in one language, they must suppress the activation of the corresponding words and syntactic (grammatical) structure from their other language. Most proficient bilingual speakers appear to do this very well, but we are interested in the effect this may have on their sentence planning processes. To examine this, we are conducting a study in which we measure a speaker’s speech onset latencies when producing different sentences in their first and second language.

Collaborators:  Linda Wheeldon, Allison Witterlin