Table_1_Neural Correlates of Executed Compared to Imagined Writing and Drawing Movements: A Functional Magnetic Resonance Imaging Study.pdf

ObjectiveIn this study we used functional magnetic resonance imaging (fMRI) to investigate whether motor imagery (MI) of handwriting and circle drawing activates a similar handwriting network as writing and drawing itself.
MethodsEighteen healthy right-handed participants wrote the German word “Wellen” and drew continuously circles in a sitting (vertical position) and lying position (horizontal position) to capture kinematic handwriting parameters such as velocity, pressure and regularity of hand movements. Afterward, they performed the same tasks during fMRI in a MI and an executed condition.
ResultsThe kinematic analysis revealed a general correlation of handwriting parameters during sitting and lying except of pen pressure during drawing. Writing compared to imagined writing was accompanied by an increased activity of the ipsilateral cerebellum and the contralateral sensorimotor cortex. Executed compared to imagined drawing revealed elevated activity of a fronto–parieto-temporal network. By contrasting writing and drawing directly, executed writing induced an enhanced activation of the left somatosensory and premotor area. The comparison of the MI of these tasks revealed a higher involvement of occipital activation during imagined writing.
ConclusionThe kinematic results pointed to a high comparability of writing in a vertical and horizontal position. Overall, we observed highly overlapping cortical activity except of a higher involvement of motor control areas during motor execution. The sparse difference between writing and drawing can be explained by highly automatized writing in healthy individuals.

研究目的 本研究采用功能磁共振成像（functional magnetic resonance imaging, fMRI）技术，探究手写与绘图的运动想象（motor imagery, MI）是否会激活与实际书写、绘图本身一致的手写神经网络。
研究方法 本研究招募18名健康右利手被试，要求其在坐姿（垂直体位）与卧位（水平体位）下书写德语单词“Wellen”，并持续绘制圆形，以采集手部运动的运动学参数，包括运动速度、笔压与动作规律性。随后，被试在功能磁共振成像扫描中完成相同任务，分为运动想象与实际执行两种条件。
研究结果 运动学分析显示，除绘图时的笔压参数外，坐姿与卧位下的手写参数总体呈现显著相关。相较于运动想象书写，实际书写伴随同侧小脑与对侧感觉运动皮层的活动增强。相较于运动想象绘图，实际绘图可使额-顶-颞网络的活动升高。通过直接对比书写与绘图任务，实际书写可诱导左侧躯体感觉区与运动前区的激活增强。对比两类任务的运动想象条件发现，想象书写时枕叶的激活程度更高。
研究结论 运动学结果表明，垂直体位与水平体位下的手写动作具有高度相似性。总体而言，除实际运动时运动控制脑区参与度更高外，两类任务的皮层激活模式高度重叠。健康个体的书写动作高度自动化，可解释书写与绘图之间的微弱差异。