Sánchez-Moguel Sergio M, Alatorre-Cruz Graciela C, Silva-Pereyra Juan, González-Salinas Sofía, Sanchez-Lopez Javier, Otero-Ojeda Gloria A, Fernández Thalía
Departamento de Neurobiología Conductual y Cognitiva, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Santiago de Querétaro, Mexico.
Escuela Superior de Atotonilco de Tula, Universidad Autónoma del Estado de Hidalgo, Atotonilco de Tula, Mexico.
Front Hum Neurosci. 2018 Jan 11;11:658. doi: 10.3389/fnhum.2017.00658. eCollection 2017.
During healthy aging, inhibitory processing is affected at the sensorial, perceptual, and cognitive levels. The assessment of event-related potentials (ERPs) during the Stroop task has been used to study age-related decline in the efficiency of inhibitory processes. Studies using ERPs have found that the P300 amplitude increases and the N500 amplitude is attenuated in healthy elderly adults compared to those in young adults. On the other hand, it has been reported that theta excess in resting EEG with eyes closed is a good predictor of cognitive decline during aging 7 years later, while a normal EEG increases the probability of not developing cognitive decline. The behavioral and ERP responses during a Counting-Stroop task were compared between 22 healthy elderly subjects with normal EEG (Normal-EEG group) and 22 healthy elderly subjects with an excess of EEG theta activity (Theta-EEG group). Behaviorally, the Normal-EEG group showed a higher behavioral interference effect than the Theta-EEG group. ERP patterns were different between the groups, and two facts are highlighted: (a) the P300 amplitude was higher in the Theta-EEG group, with both groups showing a P300 effect in almost all electrodes, and (b) the Theta-EEG group did not show an N500 effect. These results suggest that the diminishment in inhibitory control observed in the Theta-EEG group may be compensated by different processes in earlier stages, which would allow them to perform the task with similar efficiency to that of participants with a normal EEG. This study is the first to show that healthy elderly subjects with an excess of theta EEG activity not only are at risk of developing cognitive decline but already have a cognitive impairment.
在健康衰老过程中，抑制性加工在感觉、知觉和认知水平上都会受到影响。在斯特鲁普任务中对事件相关电位（ERP）的评估已被用于研究与年龄相关的抑制过程效率下降。使用ERP的研究发现，与年轻人相比，健康老年人的P300波幅增加，N500波幅减弱。另一方面，据报道，闭眼静息脑电图中θ波过多是7年后衰老过程中认知能力下降的一个良好预测指标，而正常脑电图则增加了不出现认知能力下降的可能性。对22名脑电图正常的健康老年受试者（正常脑电图组）和22名脑电图θ波活动过多的健康老年受试者（θ脑电图组）在计数-斯特鲁普任务中的行为和ERP反应进行了比较。在行为方面，正常脑电图组比θ脑电图组表现出更高的行为干扰效应。两组之间的ERP模式不同，突出了两个事实：（a）θ脑电图组的P300波幅更高，两组在几乎所有电极上都表现出P300效应，（b）θ脑电图组没有表现出N500效应。这些结果表明，θ脑电图组中观察到的抑制控制减弱可能在早期阶段由不同的过程进行补偿，这将使他们能够以与脑电图正常的参与者相似的效率完成任务。这项研究首次表明，脑电图θ波活动过多的健康老年受试者不仅有发生认知能力下降的风险，而且已经存在认知障碍。
