Neural tracking of speech mental imagery during rhythmic inner counting
Lingxi Lu,
Qian Wang,
Jingwei Sheng,
Zhaowei Liu,
Lang Qin,
Liang Li,
Jia-Hong Gao
Affiliations
Lingxi Lu
PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing, China; Center for MRI Research, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
Qian Wang
Department of Clinical Neuropsychology, Sanbo Brain Hospital, Capital Medical University, Beijing, China
Jingwei Sheng
Center for MRI Research, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
Zhaowei Liu
Center for MRI Research, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
Lang Qin
Center for MRI Research, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China; Department of Linguistics, The University of Hong Kong, Hong Kong, China
Liang Li
Speech and Hearing Research Center, School of Psychological and Cognitive Sciences, Peking University, Beijing, China
PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing, China; Center for MRI Research, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China; Beijing City Key Lab for Medical Physics and Engineering, Institution of Heavy Ion Physics, School of Physics, Peking University, Beijing, China
The subjective inner experience of mental imagery is among the most ubiquitous human experiences in daily life. Elucidating the neural implementation underpinning the dynamic construction of mental imagery is critical to understanding high-order cognitive function in the human brain. Here, we applied a frequency-tagging method to isolate the top-down process of speech mental imagery from bottom-up sensory-driven activities and concurrently tracked the neural processing time scales corresponding to the two processes in human subjects. Notably, by estimating the source of the magnetoencephalography (MEG) signals, we identified isolated brain networks activated at the imagery-rate frequency. In contrast, more extensive brain regions in the auditory temporal cortex were activated at the stimulus-rate frequency. Furthermore, intracranial stereotactic electroencephalogram (sEEG) evidence confirmed the participation of the inferior frontal gyrus in generating speech mental imagery. Our results indicate that a disassociated neural network underlies the dynamic construction of speech mental imagery independent of auditory perception.
