The overviews below will give you a glimpse into the projects we are currently working on in our research group.
Probing the time-course of word production
In order to get at the time-course of processes underlying word production, this project makes use of transcranial magnetic stimulation (TMS). TMS produces a focal magnetic field which temporarily disrupts brain communication in a given region. In other words, a virtual lesion is produced and allows us to test the functional contribution of that area at the time of stimulation. In this project, we apply TMS to three different brain regions involved in word production at six different time-points while participants name pictures they see presented before them. This allows us to assess the contribution of the stimulated area at the stimulated time. If we see a significant change in behaviour (naming speed) caused by stimulating the given area at a certain time-point, we can say something about when the given area contributes most to the word production process.
The neural dynamics of reading pathways in English
Adrian Jodzio has been awarded a grant from the Donders-BMI Exchange Trainee Program for a collaborative project with the Language Function and Dysfunction Lab at the Donders Institute and the Language, Reading and Cognitive Neuroscience Lab at the Brain and Mind Institute (Western University) to investigate the neural dynamics of reading pathways in English. This project aims to investigate brain regions involved in word reading (another type of word production process) using transcranial magnetic stimulation. We aim to test the contribution of the inferior parietal lobule and the posterior middle temporal gyrus when reading English words.
Neurophysiology of language production
Influential psycholinguistic theories (e.g., Indefrey and Levelt, 2004) posit that language production involves the transformation of a preverbal message into speech through a series of computations, from conceptual preparation to articulation, which are mapped onto specific language regions. However, the neural dynamics supporting this mapping remain unclear (for a review, see Munding et al., 2015). In a series of experiments using magnetoencephalography (MEG), we investigate when and how the key cognitive computations of lexical-semantic access, syllabification, and phonetic encoding are neurophysiologically implemented. To directly test and compare competing models of serial/cascading and parallel spatio-temporal events of language production, these experiments use both classical and novel MVPA methods, such as representational similarity analyses of MEG data at source level.