Deiber Marie-Pierre, Ibañez Vicente, Missonnier Pascal, Herrmann François, Fazio-Costa Lara, Gold Gabriel, Giannakopoulos Panteleimon
Department of Psychiatry, University Hospitals of Geneva, Switzerland.
Neurobiol Aging. 2009 Sep;30(9):1444-52. doi: 10.1016/j.neurobiolaging.2007.11.021. Epub 2008 Jan 7.
The electroencephalography (EEG) theta frequency band reacts to memory and selective attention paradigms. Global theta oscillatory activity includes a posterior phase-locked component related to stimulus processing and a frontal-induced component modulated by directed attention. To investigate the presence of early deficits in the directed attention-related network in elderly individuals with mild cognitive impairment (MCI), time-frequency analysis at baseline was used to assess global and induced theta oscillatory activity (4-6Hz) during n-back working memory tasks in 29 individuals with MCI and 24 elderly controls (EC). At 1-year follow-up, 13 MCI patients were still stable and 16 had progressed. Baseline task performance was similar in stable and progressive MCI cases. Induced theta activity at baseline was significantly reduced in progressive MCI as compared to EC and stable MCI in all n-back tasks, which were similar in terms of directed attention requirements. While performance is maintained, the decrease of induced theta activity suggests early deficits in the directed-attention network in progressive MCI, whereas this network is functionally preserved in stable MCI.
脑电图（EEG）的θ频段对记忆和选择性注意范式有反应。整体θ振荡活动包括与刺激处理相关的后部锁相成分和由定向注意调制的额叶诱发成分。为了研究轻度认知障碍（MCI）老年人定向注意相关网络中早期缺陷的存在情况，在基线时采用时频分析来评估29例MCI患者和24例老年对照（EC）在n-back工作记忆任务期间的整体和诱发θ振荡活动（4-6Hz）。在1年随访时，13例MCI患者病情仍稳定，16例病情进展。稳定和进展性MCI病例的基线任务表现相似。在所有n-back任务中，与EC和稳定MCI相比，进展性MCI在基线时的诱发θ活动显著降低，这些任务在定向注意要求方面相似。虽然表现得以维持，但诱发θ活动的降低表明进展性MCI中定向注意网络存在早期缺陷，而该网络在稳定MCI中功能保存。
