Department of Brain and Behavioral Sciences, University of Pavia, Via Bassi 21, Pavia, Italy.
Department of Brain and Behavioral Sciences, University of Pavia, Via Bassi 21, Pavia, Italy.
Neuroimage. 2024 May 1;291:120585. doi: 10.1016/j.neuroimage.2024.120585. Epub 2024 Mar 23.
The dynamics of global, state-dependent reconfigurations in brain connectivity are yet unclear. We aimed at assessing reconfigurations of the global signal correlation coefficient (GSCORR), a measure of the connectivity between each voxel timeseries and the global signal, from resting-state to a stop-signal task. The secondary aim was to assess the relationship between GSCORR and blood-oxygen-level-dependent (BOLD) activations or deactivation across three different trial-conditions (GO, STOP-correct, and STOP-incorrect).
As primary analysis we computed whole-brain, voxel-wise GSCORR during resting-state (GSCORR-rest) and stop-signal task (GSCORR-task) in 107 healthy subjects aged 21-50, deriving GSCORR-shift as GSCORR-task minus GSCORR-rest. GSCORR-tr and trGSCORR-shift were also computed on the task residual time series to quantify the impact of the task-related activity during the trials. To test the secondary aim, brain regions were firstly divided in one cluster showing significant task-related activation and one showing significant deactivation across the three trial conditions. Then, correlations between GSCORR-rest/task/shift and activation/deactivation in the two clusters were computed. As sensitivity analysis, GSCORR-shift was computed on the same sample after performing a global signal regression and GSCORR-rest/task/shift were correlated with the task performance.
Sensory and temporo-parietal regions exhibited a negative GSCORR-shift. Conversely, associative regions (ie. left lingual gyrus, bilateral dorsal posterior cingulate gyrus, cerebellum areas, thalamus, posterolateral parietal cortex) displayed a positive GSCORR-shift (FDR-corrected p < 0.05). GSCORR-shift showed similar patterns to trGSCORR-shift (magnitude increased) and after global signal regression (magnitude decreased). Concerning BOLD changes, Brodmann area 6 and inferior parietal lobule showed activation, while posterior parietal lobule, cuneus, precuneus, middle frontal gyrus showed deactivation (FDR-corrected p < 0.05). No correlations were found between GSCORR-rest/task/shift and beta-coefficients in the activation cluster, although negative correlations were observed between GSCORR-task and GO/STOP-correct deactivation (Pearson rho=-0.299/-0.273; Bonferroni-p < 0.05). Weak associations between GSCORR and task performance were observed (uncorrected p < 0.05).
GSCORR state-dependent reconfiguration indicates a reallocation of functional resources to associative areas during stop-signal task. GSCORR, activation and deactivation may represent distinct proxies of brain states with specific neurofunctional relevance.
大脑连接全局状态依赖性重构的动态目前仍不清楚。我们旨在评估全局信号相关系数（GSCORR）的重构，该系数是衡量每个体素时间序列与全局信号之间连通性的指标，从静息状态到停止信号任务。次要目标是评估 GSCORR 与血液氧合水平依赖性（BOLD）激活或去激活之间的关系，涉及三个不同的试验条件（GO、STOP-correct 和 STOP-incorrect）。
作为主要分析，我们在 107 名年龄在 21-50 岁的健康受试者中计算了静息状态（GSCORR-rest）和停止信号任务（GSCORR-task）的全脑、体素级别的 GSCORR，并得出 GSCORR-shift 作为 GSCORR-task 减去 GSCORR-rest。还在任务残差时间序列上计算了 GSCORR-tr 和 trGSCORR-shift，以量化试验过程中与任务相关的活动的影响。为了测试次要目标，首先将大脑区域分为一个显示出与三个试验条件相关的显著激活的簇和一个显示出显著去激活的簇。然后，计算了两个簇中 GSCORR-rest/task/shift 与激活/去激活之间的相关性。作为敏感性分析，在对全局信号进行回归后，对同一样本计算了 GSCORR-shift，并将 GSCORR-rest/task/shift 与任务表现相关联。
感觉和颞顶区域表现出负 GSCORR-shift。相反，联想区域（即左侧舌回、双侧背侧后扣带回、小脑区域、丘脑、后外侧顶叶皮层）显示出正 GSCORR-shift（FDR 校正 p < 0.05）。GSCORR-shift 与 trGSCORR-shift（幅度增加）和全局信号回归后（幅度减小）的模式相似。关于 BOLD 变化，Brodmann 区 6 和下顶叶显示出激活，而后顶叶、楔前叶、扣带回、中额叶显示出去激活（FDR 校正 p < 0.05）。在激活簇中，未发现 GSCORR-rest/task/shift 与 beta 系数之间存在相关性，尽管在 GSCORR-task 和 GO/STOP-correct 去激活之间观察到负相关（Pearson rho=-0.299/-0.273；Bonferroni-p < 0.05）。观察到 GSCORR 与任务表现之间存在微弱关联（未校正 p < 0.05）。
GSCORR 状态依赖性重构表明在停止信号任务期间，功能资源重新分配到联想区域。GSCORR、激活和去激活可能代表具有特定神经功能相关性的不同大脑状态的代理。
