Frutiger S A, Strother S C, Anderson J R, Sidtis J J, Arnold J B, Rottenberg D A
Neurology Department, University of Minnesota, Minneapolis, MN,USA.
Neuroimage. 2000 Nov;12(5):515-27. doi: 10.1006/nimg.2000.0644.
Imaging studies of visuomotor learning have reported practice-related activation in brain regions mediating sensorimotor functions. However, development and testing of functional motor learning models, based on the relationship between imaging and behavioral measures, is complicated by the multidimensional nature of motoric control. In the present study, multivariate techniques were used to analyze [15O]water PET and kinematic correlates of learning in a visuomotor tracing task. Fourteen subjects traced a geometric form over a series of eight tracing trials, preceded and followed by baseline trials in which they passively viewed the geometric form. Simultaneous evaluation of multiple behavioral measures indicated that performance improvement was most strongly associated with a global performance measure and least strongly associated with measures of fine motor control. Results of three independent analytic techniques (i.e., intertrial correlation matrices, power function modeling, iterative canonical variate analysis) indicated that imaging and behavioral measures were most closely related on early learning trials. Performance improvement was associated with covarying increases in normalized activity among superior parietal, postcentral gyrus, and premotor regions and covarying decreases in normalized activity among cerebellar, inferior parietal, pallidal, and medial occipital regions. These findings suggest that performance improvement may be associated with increased activation in neural systems previously implicated in visually guided reaching and decreased activation in neural systems previously implicated in attentive visuospatial processing.
视觉运动学习的影像学研究报告称，在介导感觉运动功能的脑区中存在与练习相关的激活。然而，基于影像学与行为测量之间的关系来开发和测试功能性运动学习模型，因运动控制的多维性质而变得复杂。在本研究中，采用多变量技术分析了视觉运动追踪任务中[15O]水PET与学习的运动学相关性。14名受试者在一系列8次追踪试验中追踪一个几何图形，在试验前后各有一次基线试验，即他们被动观看该几何图形。对多种行为测量的同步评估表明，性能改善与一项整体性能测量的关联最为紧密，与精细运动控制测量的关联最不紧密。三种独立分析技术（即试验间相关矩阵、幂函数建模、迭代典型变量分析）的结果表明，在早期学习试验中，影像学测量与行为测量的相关性最为密切。性能改善与顶叶上部、中央后回和运动前区归一化活动的共同增加以及小脑、顶叶下部、苍白球和枕叶内侧区归一化活动的共同减少相关。这些发现表明，性能改善可能与先前涉及视觉引导伸手动作的神经系统激活增加以及先前涉及注意力视觉空间处理的神经系统激活减少有关。
