Some hypotheses relate oscillations of EEG band power with autonomic processes derived from homeostatic control modulated by structures like the Central Autonomic Network and the Autonomic Nervous System. This research project studies the causal relationships between fluctuations of an autonomic process marker like the Heart Rate Variability (HRV) and the proposed EEG band power time series (BPts).

To verify the existence of directional causal relationships, using Granger Causality (GC) test between HRV and BPts. Analyses were performed using two databases, of 9 and 14 subjects respectively. Experiments consisted of spontaneous breathing and a controlled breathing task (CBT). GC was tested over Intrinsinc Mode Functions of HRV derived from Empirical Mode Decomposition and BPts computed over α, β and γ bands. Positive GC tests were observed through each experimental task, channels, IMFs, EEG band, and direction.

The largest number of positive GC relationships were found from BPts to HRV when testing, higher EEG band and IMF with lower spectral content. Opposite direction achieves lower total counts, but more related with IMFs of higher spectral content. Its presence also suggests that some homeostatic condition alters the BPts course given its increment under the CBT. It is important to notice that in both cases γ band achieves larger values for almost all of the studied conditions. Suggesting that such band has an important influence over HRV, but alterations on breathing condition also produce changes on BPts evolution, suggesting that the closed loop for homeostatic control alters neural dynamics at cortical level.

一些假设将 EEG 频带功率的振荡与由中枢自主网络和自主神经系统等结构调制的稳态控制派生的自主过程联系起来。该研究项目研究诸如心率变异性 (HRV) 等自主神经过程标记的波动与建议的 EEG 波段功率时间序列 (BPts) 之间的因果关系。

为了验证定向因果关系的存在，在 HRV 和 BPts 之间使用 Granger Causality (GC) 检验。使用两个数据库分别对 9 和 14 名受试者进行分析。实验包括自主呼吸和受控呼吸任务 (CBT)。GC 在从经验模式分解得出的 HRV 的固有模式函数和在α、β和γ波段计算的 BPts 上进行了测试。通过每个实验任务、通道、IMF、EEG 频带和方向观察到了积极的 GC 测试。

在测试时，从 BPts 到 HRV 发现了最多的正 GC 关系，较高的 EEG 频带和较低的频谱内容的 IMF。相反方向实现较低的总计数，但与更高光谱内容的 IMF 更相关。它的存在也表明一些稳态条件改变了 BPts 过程，因为它在 CBT 下增加。值得注意的是，在这两种情况下，γ波段在几乎所有研究条件下都达到了更大的值。表明这种带对 HRV 有重要影响，但呼吸条件的改变也会产生 BPts 进化的变化，表明稳态控制的闭环改变了皮层水平的神经动力学。