RT Journal Article
SR Electronic
T1 Prefrontal High Gamma in ECoG tags periodicity of musical rhythms in perception and imagination
JF eneuro
JO eNeuro
FD Society for Neuroscience
SP ENEURO.0413-19.2020
DO 10.1523/ENEURO.0413-19.2020
A1 S. A. Herff
A1 C. Herff
A1 A. J. Milne
A1 G. D. Johnson
A1 J. J. Shih
A1 D. J. Krusienski
YR 2020
UL http://www.eneuro.org/content/early/2020/06/25/ENEURO.0413-19.2020.abstract
AB Rhythmic auditory stimuli are known to elicit matching activity patterns in neural populations. Furthermore, recent research has established the particular importance of high-gamma brain activity in auditory processing by showing its involvement in auditory phrase segmentation and envelope-tracking. Here, we use electrocorticographic (ECoG) recordings from eight human listeners, to see whether periodicities in high-gamma activity track the periodicities in the envelope of musical rhythms during rhythm perception and imagination. Rhythm imagination was elicited by instructing participants to imagine the rhythm to continue during pauses of several repetitions. To identify electrodes whose periodicities in high-gamma activity track the periodicities in the musical rhythms, we compute the correlation between the autocorrelations (ACC) of both the musical rhythms and the neural signals. A condition in which participants listened to white noise was used to establish a baseline. High-gamma autocorrelations in auditory areas in the superior temporal gyrus and in frontal areas on both hemispheres significantly matched the autocorrelation of the musical rhythms. Overall, numerous significant electrodes are observed on the right hemisphere. Of particular interest is a large cluster of electrodes in the right prefrontal cortex that is active during both rhythm perception and imagination. This indicates conscious processing of the rhythms’ structure as opposed to mere auditory phenomena. The ACC approach clearly highlights that high-gamma activity measured from cortical electrodes tracks both attended and imagined rhythms.Significance Statement The possibility to capture high-frequency brain activity, such as High Gamma, with high spatial and temporal resolution makes invasive brain recordings extremely valuable. We present new data from an invasive ECoG study with a comparably large sample size. Deploying a new periodicity-tagging technique that extends the common frequency tagging, we found that High Gamma in auditory areas tracks periodicity. Furthermore, we use the periodic nature of musical-stimuli as a neural footprint and found that high-gamma activity in the prefontal cortex tracks periodicities of musical rhythms both during listening and imagination. The neural mechanisms involved in imagination in particular are ill understood. The present study provides evidence that the pre-frontal cortex tracks periodicities in auditory stimuli during perception and imagination, and highlights the usefulness of musical stimuli for studying neural processes.