Ashley Lewis, Ph.D.
My research is concerned with the electrophysiology of language processing. I investigate neural oscillations using EEG and MEG while participants are reading/listening, and also have an interest in the extent to which oscillatory analyses can complement information that can be gleaned from the signal using event-related potentials/fields analyses. Oscillatory neural dynamics provide a window onto the brain’s functional connectivity, and allow us to investigate the temporal dynamics of the activation and deactivation of different brain networks involved in language processing. I am interested in a wide range of linguistic and cognitive phenomena.
In the past I have worked on the following: the impact of discourse information on sentence-level processing; embodied action semantic processing in sentence contexts; subject- and object-relative clause processing related to violations of different kinds of expectations; the processing of gender and number agreement in sentence contexts by native and second-language speakers; the integration of observed gestures and prosodic cues in sentence processing; predictive coding and predictive processing in language comprehension; frequency-specific reinstatement of entrained oscillatory activity in a subsequent memory paradigm.
I am currently interested in the relationship between oscillatory activity and memory processes associated with sentence comprehension. Predictive processing during language comprehension, and how it might be related to predictive coding and neural oscillations, is another important aspect of my research that I am still pursuing. I am also actively involved in developing approaches for investigating how oscillatory activity is related to individual differences that might be relevant for sentence comprehension.
A long-term goal is to uncover to what extent the findings from the literature on oscillatory neural dynamics during language processing are specific to language, and to what extent they fit with more general ideas about the role of oscillations in neural information processing.
Lewis, A.G., Schriefers, H., Bastiaansen, M., Schoffelen, J. M. (2018). Assessing the utility of frequency tagging for tracking memory-based reactivation of word representations. Scientific Reports, 8:7897. doi:10.1038/s41598-018-26091-3
Lewis, A. G., Lemhӧfer, K., Schoffelen, J., & Schriefers, H. (2016). Gender agreement violations modulate beta oscillatory dynamics during sentence comprehension: A comparison of second language learners and native speakers. Neuropsychologia, 89, 254-272. doi:10.1016/j.neuropsychologia.2016.06.031.
Lewis, A. G., Schoffelen, J., Hoffmann, C., Bastiaansen, M. C. M., & Schriefers, H. (2016). Discourse-level semantic coherence influences beta oscillatory dynamics and the N400 during sentence comprehension. Language, Cognition and Neuroscience, 32, 601-617. doi:10.1080/23273798.2016.1211300.
Lewis, A. G., Schoffelen, J., Schriefers, H., & Bastiaansen, M. C. M. (2016). A predictive coding perspective on beta oscillations during sentence-level language comprehension. Frontiers in human neuroscience, 10. doi:10.3389/fnhum.2016.00085.
Lewis, A. G., & Bastiaansen, M. C. M. (2015). A predictive coding framework for rapid neural dynamics during sentence-level language comprehension. Cortex, 68, 155-168. doi:10.1016/j.cortex.2015.02.014.
Lewis, A. G., Wang, L., & Bastiaansen, M. C. M. (2015). Fast oscillatory dynamics during language comprehension: Unification versus maintenance and prediction? Brain and Language, 148, 51-63. doi:10.1016/j.bandl.2015.01.003.
Moreno, I., De Vega, M., León, I., Bastiaansen, M. C. M., Lewis, A. G., & Magyari, L. (2015). Brain dynamics in the comprehension of action-related language. A time-frequency analysis of mu rhythms. Neuroimage, 109, 50-62. doi:10.1016/j.neuroimage.2015.01.018.
NIH Grant RO1 HD-073288 - Retrieval Interference in Skilled and Unskilled Reading Comprehension