Thesis defense Xiaochen Zheng (Donders series 413)
28 February 2020
Promotor: prof. dr. A. Roelofs
Co-promotor: dr. K. Lemhöfer
Control and monitoring in bilingual speech production: Language selection, switching, and intrusion
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 the current thesis, 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), I believe that the knowledge gained in this thesis can significantly contribute to the research of language control, language production, and bilingualism. It can also go beyond the domain of language and provide new insights on research on e.g., performance monitoring, task switching and general cognitive control.