Learning Dynamics of Electrophysiological Brain Signals During Human Fear Conditioning (Open Data and Open Materials)

<strong>Open Data and Open Materials of: Sperl, M. F. J., Wroblewski, A., Mueller, M., Straube, B., &amp; Mueller, E. M. (2021). Learning Dynamics of Electrophysiological Brain Signals During Human Fear Conditioning. <em>NeuroImage</em>, <em>226</em>, 117569.</strong> Electrophysiological studies in rodents allow recording neural activity during threats with high temporal and spatial precision. Although fMRI has helped translate insights about the anatomy of underlying brain circuits to humans, the temporal dynamics of neural fear processes remain opaque and require EEG. To date, studies on electrophysiological brain signals in humans have helped to elucidate underlying perceptual and attentional processes, but have widely ignored how fear memory traces <em>evolve</em> over time. The low signal-to-noise ratio of EEG demands aggregations across high numbers of trials, which will wash out transient neurobiological processes that are induced by learning and prone to habituation. Here, our goal was to unravel the plasticity and temporal emergence of EEG responses during fear conditioning. To this end, we developed a new sequential-set fear conditioning paradigm that comprises three successive acquisition and extinction phases, each with a novel CS+/CS- set. Each set consists of two different neutral faces on different background colors which serve as CS+ and CS-, respectively. Thereby, this design provides sufficient trials for EEG analyses while tripling the relative amount of trials that tap into more transient neurobiological processes. Consistent with prior studies on ERP components, data-driven topographic EEG analyses revealed that ERP amplitudes were potentiated during time periods from 33–60 ms, 108–200 ms, and 468–820 ms indicating that fear conditioning prioritizes early sensory processing in the brain, but also facilitates neural responding during later attentional and evaluative stages. Importantly, averaging across the three CS+/CS- sets allowed us to probe the temporal evolution of neural processes: Responses during each of the three time windows gradually increased from early to late fear conditioning, while long-latency (460–730 ms) electrocortical responses diminished throughout fear extinction. Our novel paradigm demonstrates how short-, mid-, and long-latency EEG responses change during fear conditioning and extinction, findings that enlighten the learning curve of neurophysiological responses to threat in humans.**公开数据集与开源材料来源：** Sperl, M. F. J.、Wroblewski, A.、Mueller, M.、Straube, B.与Mueller, E. M.（2021）的研究《人类恐惧条件反射过程中脑电信号的学习动态》，刊载于《NeuroImage》第226卷，文章编号117569。啮齿类动物的电生理学研究可实现威胁情境下神经活动的高时空精度记录。尽管功能磁共振成像（fMRI）已助力将潜在脑回路解剖结构的研究结论推广至人类群体，但神经恐惧过程的时间动态仍不明确，需借助脑电图（EEG）开展相关研究。迄今为止，针对人类脑电信号的电生理学研究已为阐明潜在的感知与注意过程提供了重要支撑，但却普遍忽略了恐惧记忆痕迹随时间的演化进程。脑电图的信噪比较低，这要求基于大量试次进行信号聚合，而该操作会抹去由学习诱导且易发生习惯化的瞬时神经生物学过程。本研究旨在揭示恐惧条件反射过程中脑电反应的可塑性及其时间涌现特征。为此，我们开发了一种全新的序列集恐惧条件反射范式，该范式包含三个连续的习得与消退阶段，每个阶段均采用一套全新的阳性条件刺激（CS+）与阴性条件刺激（CS-）组合。每套刺激组合由两种呈现于不同背景色的中性人脸构成，分别作为CS+与CS-。该设计既可为脑电图分析提供充足的试次数量，同时将可探测瞬时神经生物学过程的有效试次相对占比提升至原有水平的三倍。与此前关于事件相关电位（ERP）成分的研究结论一致，基于数据驱动的脑电地形分析显示，ERP幅值在33–60 ms、108–200 ms以及468–820 ms三个时间段内均出现显著增强，表明恐惧条件反射优先激活大脑的早期感觉加工通路，同时也能促进后续注意与评价阶段的神经响应。尤为关键的是，对三套CS+/CS-组合的数据进行平均处理，使我们得以精准探测神经过程的时间演化轨迹：三个时间窗口内的脑电响应均随恐惧条件反射的进程从早期到晚期逐渐增强，而长潜伏期（460–730 ms）的脑电响应则在恐惧消退过程中逐步减弱。本研究的全新范式阐明了短、中、长潜伏期脑电响应在恐惧条件反射与消退过程中的动态变化规律，相关发现为理解人类面对威胁时神经生理响应的学习曲线提供了全新的学术视角。