Department of Neurological Surgery, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, USA.
Department of Neurological Surgery, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, USA.
World Neurosurg. 2021 Aug;152:e32-e44. doi: 10.1016/j.wneu.2021.04.023. Epub 2021 Apr 16.
Coherence between the hippocampus and other brain structures has been shown with the theta frequency (3-8 Hz). Cortical decreases in theta coherence are believed to reflect response accuracy efficiency. However, the role of theta coherence during conflict resolution is poorly understood in noncortical areas. In this study, coherence between the hippocampus and orbitofrontal cortex (OFC) was measured during a conflict resolution task. Although both brain areas have been previously implicated in the Stroop task, their interactions are not well understood.
Nine patients were implanted with stereotactic electroencephalography contacts in the hippocampus and OFC. Local field potential data were sampled throughout discrete phases of a Stroop task. Coherence was calculated for hippocampal and OFC contact pairs, and coherence spectrograms were constructed for congruent and incongruent conditions. Coherence changes during cue processing were identified using a nonparametric cluster-permutation t test. Group analysis was conducted to compare overall theta coherence changes among conditions.
In 6 of 9 patients, decreased theta coherence was observed only during the incongruent condition (P < 0.05). Congruent theta coherence did not change from baseline. Group analysis showed lower theta coherence for the incongruent condition compared with the congruent condition (P < 0.05).
Theta coherence between the hippocampus and OFC decreased during conflict. This finding supports existing theories that theta coherence desynchronization contributes to improved response accuracy and processing efficiency during conflict resolution. The underlying theta coherence observed between the hippocampus and OFC during conflict may be distinct from its previously observed role in memory.
已显示海马体与其他大脑结构之间具有θ频率（3-8 Hz）的相干性。据信，皮质中的θ相干性降低反映了响应准确性效率。然而，在非皮质区域中，θ相干性在冲突解决中的作用还了解甚少。在这项研究中，在冲突解决任务期间测量了海马体和眶额皮质（OFC）之间的相干性。尽管这两个大脑区域以前都与Stroop 任务有关，但它们的相互作用尚不清楚。
九名患者被植入海马体和 OFC 的立体定向脑电图接触点。在 Stroop 任务的各个离散阶段都采样局部场电位数据。为海马体和 OFC 接触对计算相干性，并为一致和不一致条件构建相干频谱图。使用非参数聚类置换 t 检验识别线索处理过程中的相干性变化。进行组分析以比较条件之间的总体θ相干性变化。
在 9 名患者中的 6 名患者中，仅在不一致条件下观察到θ相干性降低（P <0.05）。一致条件下的θ相干性没有从基线改变。组分析显示，与一致条件相比，不一致条件下的θ相干性较低（P <0.05）。
海马体和 OFC 之间的θ相干性在冲突期间降低。这一发现支持现有的理论，即θ相干性去同步有助于提高冲突解决过程中的响应准确性和处理效率。在冲突期间观察到的海马体和 OFC 之间的潜在θ相干性可能与其先前观察到的记忆作用不同。
