Institute for Human Neuroscience, Boys Town National Research Hospital, Boys Town, NE 68010, USA.
College of Medicine, University of Nebraska Medical Center (UNMC), Omaha, NE 68198, USA.
Cereb Cortex. 2022 Nov 21;32(23):5376-5387. doi: 10.1093/cercor/bhac021.
Semantic processing is the ability to discern and maintain conceptual relationships among words and objects. While the neural circuits serving semantic representation and controlled retrieval are well established, the neuronal dynamics underlying these processes are poorly understood. Herein, we examined 25 healthy young adults who completed a semantic relation word-matching task during magnetoencephalography (MEG). MEG data were examined in the time-frequency domain and significant oscillatory responses were imaged using a beamformer. Whole-brain statistical analyses were conducted to compare semantic-related to length-related neural oscillatory responses. Time series were extracted to visualize the dynamics and were linked to task performance using structural equation modeling. The results indicated that participants had significantly longer reaction times in semantic compared to length trials. Robust MEG responses in the theta (3-6 Hz), alpha (10-16 Hz), and gamma (64-76 Hz and 64-94 Hz) bands were observed in parieto-occipital and frontal cortices. Whole-brain analyses revealed stronger alpha oscillations in a left-lateralized network during semantically related relative to length trials. Importantly, stronger alpha oscillations in the left superior temporal gyrus during semantic trials predicted faster responses. These data reinforce existing literature and add novel temporal evidence supporting the executive role of the semantic control network in behavior.
语义处理是辨别和维持词与物之间概念关系的能力。虽然用于语义表示和控制检索的神经回路已经得到很好的证实，但这些过程背后的神经元动力学仍知之甚少。在此，我们检查了 25 名健康的年轻成年人，他们在磁共振脑磁图 (MEG) 期间完成了语义关系词匹配任务。使用波束形成器在时频域检查了 MEG 数据，并对显著的振荡响应进行了成像。进行了全脑统计分析，以比较语义相关和长度相关的神经振荡反应。提取时间序列以可视化动力学，并使用结构方程建模将其与任务表现相关联。结果表明，与长度试验相比，参与者在语义试验中反应时间明显更长。在顶叶和额叶皮质中观察到 theta（3-6 Hz）、alpha（10-16 Hz）和 gamma（64-76 Hz 和 64-94 Hz）频段中强大的 MEG 响应。全脑分析显示，在语义相关的试验中，左侧偏侧化网络中的 alpha 振荡更强。重要的是，在语义试验中，左颞上回的 alpha 振荡越强，反应越快。这些数据强化了现有文献，并提供了新的时间证据，支持语义控制网络在行为中的执行作用。
