Kamal Farooq, Morrison Cassandra, Campbell Kenneth, Taler Vanessa
School of Psychology, University of Ottawa, Ontario, ON, Canada.
Bruyère Research Institute, Ottawa, ON, Canada.
Front Aging Neurosci. 2021 Apr 1;13:659618. doi: 10.3389/fnagi.2021.659618. eCollection 2021.
Much research effort is currently devoted to the development of a simple, low-cost method to determine early signs of Alzheimer's disease (AD) pathology. The present study employs a simple paradigm in which event-related potentials (ERPs) were recorded to a single auditory stimulus that was presented rapidly or very slowly while the participant was engaged in a visual task. A multi-channel EEG was recorded in 20 healthy older adults and 20 people with mild cognitive impairment (MCI). In two different conditions, a single 80 dB sound pressure level (SPL) auditory stimulus was presented every 1.5 s (fast condition) or every 12.0 s (slow condition). Participants were instructed to watch a silent video and ignore the auditory stimuli. Auditory processing thus occurred passively. When the auditory stimuli were presented rapidly (every 1.5 s), N1 and P2 amplitudes did not differ between the two groups. When the stimuli were presented very slowly, the amplitude of N1 and P2 increased in both groups and their latencies were prolonged. The amplitude of N1 did not significantly differ between the two groups. However, the subsequent positivity was reduced in people with MCI compared to healthy older adults. This late positivity in the slow condition may reflect a delayed P2 or a summation of a composite P2 + P3a. In people with MCI, the priority of processing may not be switched from the visual task to the potentially much more relevant auditory input. ERPs offer promise as a means to identify the pathology underlying cognitive impairment associated with MCI.
目前，大量研究工作致力于开发一种简单、低成本的方法来确定阿尔茨海默病（AD）病理的早期迹象。本研究采用了一种简单的范式，即当参与者进行视觉任务时，记录与单个听觉刺激相关的事件相关电位（ERP），该听觉刺激以快速或非常缓慢的速度呈现。对20名健康老年人和20名轻度认知障碍（MCI）患者进行了多通道脑电图记录。在两种不同条件下，每1.5秒（快速条件）或每12.0秒（慢速条件）呈现一次80分贝声压级（SPL）的单个听觉刺激。参与者被指示观看无声视频并忽略听觉刺激。因此，听觉处理是被动进行的。当听觉刺激快速呈现（每1.5秒）时，两组之间的N1和P2波幅没有差异。当刺激非常缓慢地呈现时，两组的N1和P2波幅均增加，且潜伏期延长。两组之间N1波幅没有显著差异。然而，与健康老年人相比，MCI患者随后的正波减少。慢速条件下的这种晚期正波可能反映了延迟的P2或复合P2 + P3a的总和。在MCI患者中，处理的优先级可能不会从视觉任务切换到潜在更相关的听觉输入。ERP有望作为一种手段来识别与MCI相关的认知障碍背后的病理。
