Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.
J Cogn Neurosci. 2012 Mar;24(3):698-706. doi: 10.1162/jocn_a_00167. Epub 2011 Nov 18.
Forward predictions are crucial in motor action (e.g., catching a ball, or being tickled) but may also apply to sensory or cognitive processes (e.g., listening to distorted speech or to a foreign accent). According to the "internal forward model," the cerebellum generates predictions about somatosensory consequences of movements. These predictions simulate motor processes and prepare respective cortical areas for anticipated sensory input. Currently, there is very little evidence that a cerebellar forward model also applies to other sensory domains. In the current study, we address this question by examining the role of the cerebellum when auditory stimuli are anticipated as a consequence of a motor act. We applied an N100 suppression paradigm and compared the ERP in response to self-initiated with the ERP response to externally produced sounds. We hypothesized that sensory consequences of self-initiated sounds are precisely predicted and should lead to an N100 suppression compared with externally produced sounds. Moreover, if the cerebellum is involved in the generation of a motor-to-auditory forward model, patients with focal cerebellar lesions should not display an N100 suppression effect. Compared with healthy controls, patients showed a largely attenuated N100 suppression effect. The current results suggest that the cerebellum forms not only motor-to-somatosensory predictions but also motor-to-auditory predictions. This extends the cerebellar forward model to other sensory domains such as audition.
前向预测在运动动作中至关重要（例如，接球或被挠痒痒），但也可能适用于感觉或认知过程（例如，听失真的语音或外国口音）。根据“内部前向模型”，小脑会生成有关运动产生的躯体感觉后果的预测。这些预测模拟运动过程，并为预期的感觉输入准备相应的皮质区域。目前，几乎没有证据表明小脑的前向模型也适用于其他感觉领域。在当前的研究中，我们通过检查听觉刺激作为运动行为的后果被预期时小脑的作用来解决这个问题。我们应用了 N100 抑制范式，并比较了对自我发起的声音和对外生声音的 ERP 响应。我们假设，自我发起声音的感觉后果是精确预测的，与外部产生的声音相比，应该导致 N100 抑制。此外，如果小脑参与生成运动到听觉的前向模型，那么患有局灶性小脑病变的患者不应显示 N100 抑制效应。与健康对照组相比，患者的 N100 抑制效应明显减弱。目前的结果表明，小脑不仅形成运动到躯体感觉的预测，还形成运动到听觉的预测。这将小脑的前向模型扩展到其他感觉领域，如听觉。
