Department of Occupational Therapy, University of Alberta, Edmonton, Alberta, Canada.
Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
Eur J Neurosci. 2023 Sep;58(5):3286-3298. doi: 10.1111/ejn.16096. Epub 2023 Jul 27.
Mental representations of our bodies are thought to influence how we interact with our surroundings. We can examine these mental representations through motor imagery, the imagination of movement using scalp EEG recordings. The visual modality of motor imagery emphasises 'seeing' the imagined movement and is associated with increased activity in the alpha rhythm (8-14 Hz) measured over the occipital regions. The kinaesthetic modality emphasises 'feeling' the movement and is associated with decreased activity in the mu rhythm (8-14 Hz) measured over the sensorimotor cortices. These two modalities can be engaged in isolation or together. We recorded EEG activity while 37 participants (17 left-hand dominant) completed an objective hand motor imagery task. Left-handers exhibited significant activity differences between occipital and motor regions only during imagery of right-hand (non-dominant-hand) movements. This difference was primarily driven by less oscillatory activity in the mu rhythm, which may reflect a shift in imagery strategy wherein participants placed more effort into generating the kinaesthetic sensations of non-dominant-hand imagery. Spatial features of 8-14 Hz activity generated from principal component analysis (PCA) provide further support for a strategy shift. Right-handers also exhibited significant differences between alpha and mu activity during imagery of non-dominant movements. However, this difference was not primarily driven by either rhythm, and no differences were observed in the group's PCA results. Together, these findings indicate that individuals imagine movement differently when it involves their dominant versus non-dominant hand, and left-handers may be more flexible in their motor imagery strategies.
我们的身体的心理表象被认为会影响我们与周围环境的相互作用。我们可以通过运动意象来检查这些心理表象，即通过头皮 EEG 记录来想象运动。运动意象的视觉模态强调“看到”想象中的运动，与枕叶区域中增加的 alpha 节律（8-14 Hz）活动相关。动觉模态强调“感觉”运动，与传感器运动皮质中减少的 mu 节律（8-14 Hz）活动相关。这两种模态可以单独或一起参与。我们记录了 37 名参与者（17 名左撇子）在完成客观手部运动意象任务时的 EEG 活动。左撇子在想象右手（非优势手）运动时，仅在枕叶和运动区域之间表现出显著的活动差异。这种差异主要是由于 mu 节律的振荡活动减少，这可能反映出意象策略的转变，即参与者在生成非优势手意象的动觉感觉方面投入了更多的努力。主成分分析（PCA）生成的 8-14 Hz 活动的空间特征进一步支持了策略转变。右撇子在想象非优势运动时，alpha 和 mu 活动之间也存在显著差异。然而，这种差异不是由任何一种节律驱动的，而且在该组的 PCA 结果中没有观察到差异。综上所述，这些发现表明，当涉及到优势手和非优势手时，个体的运动想象方式不同，而左撇子可能在他们的运动意象策略上更加灵活。
