Frequency Selectivity of Persistent Cortical Oscillatory Responses to Auditory Rhythmic Stimulation

Cortical oscillations have been proposed to play a functional role in speech and music perception, attentional selection, and working memory, via the mechanism of neural entrainment. One of the properties of neural entrainment that is often taken for granted is that its modulatory effect on ongoing oscillations outlasts rhythmic stimulation. We tested the existence of this phenomenon by studying cortical neural oscillations during and after presentation of melodic stimuli in a passive perception paradigm. Melodies were composed of similar to 60 and similar to 80 Hz tones embedded in a 2.5 Hz stream. Using intracranial and surface recordings in male and female humans, we reveal persistent oscillatory activity in the high-gamma band in response to the tones throughout the cortex, well beyond auditory regions. By contrast, in response to the 2.5 Hz stream, no persistent activity in any frequency band was observed. We further show that our data are well captured by a model of damped harmonic oscillator and can be classified into three classes of neural dynamics, with distinct damping properties and eigenfrequencies. This model provides a mechanistic and quantitative explanation of the frequency selectivity of auditory neural entrainment in the human cortex.

Automated summary

The study found that cortical neural oscillations in response to tones exhibit persistent activity, while there was no persistent activity in response to a 2.5 Hz stream in a passive perception paradigm. The data were well captured by a damped harmonic oscillator model and classified into three classes of neural dynamics with distinct damping properties and eigenfrequencies, providing a mechanistic explanation of frequency selectivity in auditory neural entrainment in the human cortex.