Curot Jonathan, Dornier Vincent, Valton Luc, Denuelle Marie, Robin Alexis, Rulquin Florence, Sol Jean-Christophe, De Barros Amaury, Trébuchon Agnès, Bénar Christian, Bartolomei Fabrice, Barbeau Emmanuel J
Toulouse University Hospital, France; Brain Research and Cognition Center (CerCo), CNRS, UMR5549, France; University of Toulouse, Faculty of Health, France.
Brain Research and Cognition Center (CerCo), CNRS, UMR5549, France; University of Toulouse, Faculty of Health, France.
Cortex. 2025 Feb;183:349-372. doi: 10.1016/j.cortex.2024.11.015. Epub 2024 Dec 15.
The precise and fleeting moment of rich recollection triggered by an environmental cue is difficult to reproduce in the lab. However, epilepsy patients can experience sudden reminiscences after intracranial electrical brain stimulation (EBS). In these cases, the transient brain state related to the activation of the engram and its conscious perception can be recorded using intracerebral EEG (iEEG). We collected various EBS-induced reminiscences for iEEG analysis, classifying them as follows: no or weak details (familiarity); moderate details and context (semantic and personal semantic memories); high details and context (episodic). Nine brain areas were selected within the temporal lobes (including the hippocampus and temporal neocortex, ipsi- and contralateral) and the insula, defining a network (each area as a node). Functional connectivity was measured by estimating pair-wise non-linear correlations between signals recorded from these brain regions during different memory events. Seventeen reminiscences in six patients (2 episodic, 10 personal semantic, 2 semantic memories, 5 familiar objects, 1 déjà-rêvé) were compared to 18 control experiential phenomena (unrelated to reminiscence), 18 negative EBS (which failed to elicit memories or other phenomena) in the same locations, and pre-EBS baseline activity. The global functional connectivity in the network was higher following EBS-induced reminiscences than during baseline activity, control phenomena, or negative EBS. The degree of connectivity increased with the complexity of memories; it was higher for detailed and contextualized memories like episodic memories. More significant links compared to baseline (edges with higher non-linear correlation relative to baseline) were observed for episodic memories than for less contextualized memories. These increases in connectivity occurred in all frequency bands, except the delta band. Our results support understanding declarative memory retrieval as having a multiplexed organization. They also show that richer memories activated by intracranial EBS are related to more complex connectivity patterns across medial and neocortical temporal lobe structures.
由环境线索引发的丰富回忆那精确而短暂的瞬间很难在实验室中重现。然而，癫痫患者在进行颅内脑电刺激（EBS）后会经历突然的回忆。在这些情况下，可以使用脑内脑电图（iEEG）记录与记忆痕迹激活及其意识感知相关的短暂脑状态。我们收集了各种EBS诱发的回忆用于iEEG分析，并将其分类如下：无或细节薄弱（熟悉感）；中等细节和背景（语义和个人语义记忆）；高度细节和背景（情景记忆）。在颞叶（包括海马体和颞叶新皮质，同侧和对侧）以及脑岛内选择了九个脑区，定义了一个网络（每个区域为一个节点）。通过估计在不同记忆事件期间从这些脑区记录的信号之间的成对非线性相关性来测量功能连接性。将六名患者的17次回忆（2次情景记忆、10次个人语义记忆、2次语义记忆、5次熟悉物体、1次似曾梦境）与18种对照体验现象（与回忆无关）、在相同位置的18次阴性EBS（未能引发记忆或其他现象）以及EBS前的基线活动进行比较。EBS诱发回忆后，网络中的全局功能连接性高于基线活动、对照现象或阴性EBS期间。连接程度随着记忆的复杂性而增加；对于像情景记忆这样详细且有背景的记忆来说更高。与基线相比，情景记忆比背景化程度较低的记忆观察到更多显著的连接（相对于基线具有更高非线性相关性的边）。这些连接性的增加发生在所有频段，除了δ频段。我们的结果支持将陈述性记忆检索理解为具有多重组织。它们还表明，颅内EBS激活的更丰富记忆与内侧和新皮质颞叶结构之间更复杂的连接模式相关。
