Department of Medical Physics and Bioengineering, Christchurch Hospital, 8011 Christchurch, New Zealand.
IEEE Trans Neural Syst Rehabil Eng. 2010 Oct;18(5):479-88. doi: 10.1109/TNSRE.2010.2050782. Epub 2010 Jun 3.
As a precursor for investigation of changes in neural activity underlying lapses of responsiveness, we set up a system to simultaneously record functional magnetic resonance imaging (fMRI), eye-video, EOG, and continuous visuomotor response inside an MRI scanner. The BOLD fMRI signal was acquired during a novel 2-D tracking task in which participants (10 males, 10 females) were cued to either briefly stop tracking and close their eyes (Stop +Close) or to briefly stop tracking (Stop) only. The onset and duration of eye-closure and stopping were identified post hoc from eye-video, EOG, and visuomotor response. fMRI data were analyzed using a general linear model (GLM) and tensorial independent component analysis (TICA). The GLM-based analysis identified predominantly increased blood oxygenation level dependent (BOLD) activity during eye-closure and stopping in multisensory areas, sensory-motor integration areas, and default-mode regions. Stopping during tracking elicited increased activity in visual processing areas, sensory-motor integration areas, and premotor areas. TICA separated the spatio-temporal pattern of activity into multiple task-related networks including the 1) occipito-medial frontal eye-movement network, 2) sensory areas, 3) left-lateralized visuomotor network, and 4) fronto-parietal visuomotor network, which were modulated differently by Stop +Close and Stop. The results demonstrate the merits of using simultaneous fMRI, behavioral, and physiological recordings to investigate the mechanisms underlying complex human behaviors in the human brain. Furthermore, knowledge of widespread modulations in brain activity due to voluntary eye-closure or stopping during a continuous visuomotor task is important for studies of the brain mechanisms underlying involuntary behaviors, such as microsleeps and attention lapses, which are often accompanied by brief eye-closure and/or response failures.
作为探究反应迟钝相关神经活动变化的前期研究，我们建立了一个系统，可在磁共振成像仪内同步记录功能磁共振成像（fMRI）、眼视频、眼电图和连续视觉运动反应。在一个新颖的 2D 追踪任务中采集 BOLD fMRI 信号，在此任务中，被试（10 名男性，10 名女性）会受到提示，要么短暂停止追踪并闭眼（Stop+Close），要么仅短暂停止追踪（Stop）。闭眼和停止的开始和持续时间是从眼视频、眼电图和视觉运动反应中事后确定的。使用广义线性模型（GLM）和张量独立成分分析（TICA）对 fMRI 数据进行分析。基于 GLM 的分析发现，在多感觉区域、感觉运动整合区域和默认模式区域，闭眼和停止期间主要出现血氧水平依赖（BOLD）活动增加。在追踪过程中停止会引起视觉处理区域、感觉运动整合区域和前运动区域的活动增加。TICA 将活动的时空模式分为多个与任务相关的网络，包括 1）枕内侧额眼运动网络，2）感觉区域，3）左侧视觉运动网络和 4）额顶视觉运动网络，它们受 Stop+Close 和 Stop 的调节方式不同。这些结果证明了使用同步 fMRI、行为和生理记录来研究人类大脑中复杂行为机制的优点。此外，由于在连续视觉运动任务期间自愿闭眼或停止而导致大脑活动广泛调节的知识，对于研究无意识行为（如微睡眠和注意力不集中）的大脑机制非常重要，这些行为通常伴随着短暂的闭眼和/或反应失败。
