Results of several neuroimaging studies support the functional equivalence model, which states that motor imagery (MI) and motor execution (ME) involve the same processes, except for the final execution component. In contrast, the motor-cognitive model implies that MI additionally involves frontal executive control processes. However, according to some authors MI may actually be more comparable to motor preparation (MP). In the current electroencephalographic study, a version of the discrete sequence production paradigm was employed in which human participants initially had to prepare a sequence of five finger movements that subsequently had to be executed, imagined, or withheld. MI, ME, and MP were compared by computing event-related (de)-synchronization in the theta, alpha/mu, and beta bands. Results revealed a major increase in frontal theta power during MI as compared to ME and MP. At the end of the examined intervals, a posterior reduction in alpha power was present during ME and MP, but not during MI. Finally, above sensorimotor areas a decrease in beta power was observed that was most pronounced in the case of ME. The increase of frontal theta activity during MI may reflect increased effort, while the absence of a reduction in posterior alpha power suggests no major involvement of visuospatial attention and/or visual imagery. The present findings favor the motor-cognitive model, as it predicts extra involvement of frontal executive processes during MI.

几项神经影像学研究的结果支持功能等效模型，该模型指出运动想象 (MI) 和运动执行 (ME) 涉及相同的过程，除了最终的执行组件。相比之下，运动认知模型意味着 MI 还涉及额叶执行控制过程。然而，根据一些作者的说法，MI 实际上可能与运动准备 (MP) 更具可比性。在当前的脑电图研究中，采用了离散序列产生范式的一个版本，其中人类参与者最初必须准备五个手指运动的序列，随后必须执行、想象或保留这些动作。MI、ME 和 MP 通过计算 theta、alpha/mu 和 beta 波段中的事件相关（去）同步进行比较。结果显示，与 ME 和 MP 相比，MI 期间额叶 theta 功率显着增加。在检查的间隔结束时，在 ME 和 MP 期间存在 alpha 功率的后验减少，但在 MI 期间没有。最后，在感觉运动区域上方观察到 β 功率的降低，这在 ME 的情况下最为明显。MI 期间额叶 theta 活动的增加可能反映了努力的增加，而后 alpha 功率没有减少表明视觉空间注意力和/或视觉图像没有主要参与。本研究结果支持运动认知模型，因为它预测 MI 期间额叶执行过程的额外参与。在感觉运动区域上方观察到β功率的降低，这在 ME 的情况下最为明显。MI 期间额叶 theta 活动的增加可能反映了努力的增加，而后 alpha 功率没有减少表明视觉空间注意力和/或视觉图像没有主要参与。本研究结果支持运动认知模型，因为它预测 MI 期间额叶执行过程的额外参与。在感觉运动区域上方观察到β功率的降低，这在 ME 的情况下最为明显。MI 期间额叶 theta 活动的增加可能反映了努力的增加，而后 alpha 功率没有减少表明视觉空间注意力和/或视觉图像没有主要参与。本研究结果支持运动认知模型，因为它预测 MI 期间额叶执行过程的额外参与。