Projects

Neural Mechanisms of Generalization and Novel Inference

The ability to generalize previously learned information to novel situations is fundamental for adaptive behavior. When seeing the word “un-reject-able-ish” for the first time, one can quickly infer its meaning by generalizing the knowledge of its constituent parts and integrating them based on certain abstract structural rules (e.g., the sequential order of the word parts). How do we generate novel, compositional meaning? What are the neuro-computational mechanisms that underlie structural inference in not only meaning generalization but also across different cognitive domains? This efficient but also flexible inferential process may leverage neural mechanisms commonly studied in the nonlinguistic domains of action planning, relational memory and model-based reinforcement learning, including medial prefrontal-hippocampal circuitry. To address these questions, I have developed novel experimental paradigms for quantifying novel structural inference. I use neuroimaging techniques (e.g., fMRI, MEG) to probe the neural underpinning of the learning and generalization processes. I also collaborate on a pharmacological study to access dopamine’s role in supporting such flexible behavior.

Control and Monitoring in Bilingual Speech Production

Although bilingual speakers are very good at selectively using one language rather than another, sometimes language intrusion occurs (e.g., a Dutch-English bilingual says “where is my fiets” to her English-speaking friend when she finds her bike stolen). In my PhD project, I consider language intrusion to be a failure of the control system, and investigated how and why such disturbance of the control process takes place. To this end, I employed behavioral and electrophysiological experiments to examine the role of top-down control in language switching, the functional locus of language selection, the monitoring process of speech errors, and the dynamics of inhibitory control during language mixing. As a successful attempt to study the language control mechanism from a non-traditional perspective (i.e., by looking into the actual errors), the knowledge gained in this project significantly contributes to the research of language control, language production, and bilingualism. It also goes beyond the domain of language and provides new insights on research on e.g., performance monitoring, task switching and general cognitive control.