Goldsmiths, University of London, New Cross London SE14 6NW, UK.
QuestIT, Via L. Cialfi 23, 53100 Siena.
Cereb Cortex. 2024 Nov 5;34(11). doi: 10.1093/cercor/bhae442.
Previous interoception research has demonstrated that sensory processing is reduced during cardiac systole, an effect associated with diminished cortical excitability, possibly due to heightened baroreceptor activity. This study aims to determine how phases of the cardiac cycle-systole and diastole-modulate neural sensorimotor activity during motor imagery (MI) and motor execution (ME). We hypothesised that MI performance, indexed by enhanced suppression of contralateral sensorimotor alpha (8-13 Hz) and beta (14-30 Hz) activity, would be modulated by the cardiac phases, with improved performance during diastole due to enhanced sensory processing of movement cues. Additionally, we investigated whether movement cues during systole or diastole enhance muscle activity. To test these hypotheses, 29 participants were instructed to perform or imagine thumb abductions, while we recorded their electroencephalography, electrocardiogram, and electromyogram (EMG) activity. We show that imaginary movements instructed during diastole lead to more pronounced suppression of alpha and beta activity in contralateral sensorimotor cortices, with no significant cardiac timing effects observed during ME as confirmed by circular statistics. Additionally, diastole was associated with significantly increased EMG on the side of actual and, to a lesser degree, imagined movements. Our study identifies optimal cardiac phases for MI performance, suggesting potential pathways to enhance MI-based assistive technologies.
先前的内脏感觉研究表明，在心脏收缩期，感觉处理会减少，这一效应与皮质兴奋性降低有关，可能是由于压力感受器活动增强所致。本研究旨在确定心动周期的各个阶段——收缩期和舒张期——如何调节运动想象（MI）和运动执行（ME）期间的神经感觉运动活动。我们假设，MI 表现，以对侧感觉运动 alpha（8-13 Hz）和 beta（14-30 Hz）活动的增强抑制为指标，将受到心动周期的调节，由于运动线索的感觉处理增强，舒张期的表现会得到改善。此外，我们还研究了收缩期或舒张期的运动线索是否会增强肌肉活动。为了检验这些假设，我们要求 29 名参与者执行或想象拇指外展，同时记录他们的脑电图、心电图和肌电图（EMG）活动。我们发现，在舒张期指示的想象运动导致对侧感觉运动皮质中 alpha 和 beta 活动的抑制更为明显，而在 ME 期间没有观察到明显的心脏定时效应，这一点通过循环统计得到了证实。此外，舒张期与实际运动和在较小程度上想象运动侧的 EMG 显著增加有关。我们的研究确定了 MI 表现的最佳心动周期，为增强基于 MI 的辅助技术提供了潜在途径。
