Pavlov Institute of Physiology, Russian Academy of Sciences, Makarova emb. 6, 199034 Saint Petersburg, Russia.
Brain Res. 2021 Feb 1;1752:147232. doi: 10.1016/j.brainres.2020.147232. Epub 2020 Dec 29.
The present study investigates the event-related oscillations underlying the motion-onset response (MOR) evoked by sounds moving at different velocities. EEG was recorded for stationary sounds and for three patterns of sound motion produced by changes in interaural time differences. We explored the effect of motion velocity on the MOR potential, and also on the event-related spectral perturbation (ERSP) and inter-trial phase coherence (ITC) calculated from the time-frequency decomposition of EEG signals. The phase coherence of slow oscillations increased with an increase in motion velocity similarly to the magnitude of cN1 and cP2 components of the MOR response. The delta-to-alpha inter-trial spectral power remained at the same level up to, but not including, the highest velocity, suggesting that gradual spatial changes within the sound did not induce non-coherent activity. Conversely, the abrupt sound displacement induced theta-alpha oscillations which had low phase consistency. The findings suggest that the MOR potential could be mainly generated by the phase resetting of slow oscillations, and the degree of phase coherence may be considered as a neurophysiological indicator of sound motion processing.
本研究探讨了不同速度运动声音诱发的运动起始反应（MOR）的事件相关振荡。记录了固定声音和三种由耳间时间差异变化产生的声音运动模式的 EEG。我们探讨了运动速度对 MOR 电位的影响，以及对从 EEG 信号时频分解计算得出的事件相关频谱微扰（ERSP）和试验间相位相干性（ITC）的影响。慢振荡的相位相干性随着运动速度的增加而增加，类似于 MOR 反应的 cN1 和 cP2 分量的幅度。直到但不包括最高速度，delta-alpha 试验间频谱功率保持在相同水平，这表明声音内的逐渐空间变化不会引起非相干活动。相反，突然的声音位移诱导了具有低相位一致性的 theta-alpha 振荡。研究结果表明，MOR 电位可能主要由慢振荡的相位复位产生，相位相干性的程度可被视为声音运动处理的神经生理指标。
