Department of Electronics and Informatics (ETRO), Vrije Universiteit Brussel, Brussels, Belgium.
AIMS Lab, Center for Neurosciences, Vrije Universiteit Brussel, Brussels, Belgium.
Mult Scler. 2024 Jul;30(8):1036-1046. doi: 10.1177/13524585241253777. Epub 2024 May 20.
An imbalance of excitatory and inhibitory synaptic transmission in multiple sclerosis (MS) may lead to cognitive impairment, such as impaired working memory. The 1/f slope of electroencephalography/magnetoencephalography (EEG/MEG) power spectra is shown to be a non-invasive proxy of excitation/inhibition balance. A flatter slope is associated with higher excitation/lower inhibition.
To assess the 1/f slope modulation induced by stimulus and its association with behavioral and cognitive measures.
We analyzed MEG recordings of 38 healthy controls (HCs) and 79 people with multiple sclerosis (pwMS) while performing an n-back task including target and distractor stimuli. Target trials require an answer, while distractor trials do not. We computed the 1/f spectral slope through the fitting oscillations and one over f (FOOOF) algorithm within the time windows 1 second before and after each stimulus presentation.
We observed a flatter 1/f slope after distractor stimuli in pwMS compared to HCs. The 1/f slope was significantly steeper after stimulus for both HCs and pwMS and was significantly correlated with reaction times. This modulation in 1/f slope was significantly correlated with visuospatial memory assessed by the BVMT-R test.
Our results suggest possible inhibitory mechanism deficits in pwMS during a working memory task.
多发性硬化症（MS）中兴奋性和抑制性突触传递的失衡可能导致认知障碍，如工作记忆受损。脑电图/脑磁图（EEG/MEG）功率谱的 1/f 斜率被证明是兴奋性/抑制性平衡的非侵入性替代指标。斜率越平坦，兴奋性越高，抑制性越低。
评估刺激引起的 1/f 斜率调制及其与行为和认知测量的关系。
我们分析了 38 名健康对照者（HCs）和 79 名多发性硬化症患者（pwMS）在执行 n-back 任务时的 MEG 记录，该任务包括目标和分心刺激。目标试验需要回答，而分心试验不需要。我们通过在每个刺激呈现前后 1 秒的时间窗口内进行拟合振荡和 1/f（FOOOF）算法计算 1/f 光谱斜率。
我们观察到 pwMS 在分心刺激后 1/f 斜率较 HCs 更平坦。HCs 和 pwMS 在刺激后 1/f 斜率明显变陡，与反应时间明显相关。这种 1/f 斜率的调制与 BVMT-R 测试评估的视觉空间记忆明显相关。
我们的结果表明，在工作记忆任务中，pwMS 可能存在抑制机制缺陷。
