Rae Charlotte L, Critchley Hugo D, Seth Anil K
Sackler Centre for Consciousness Science, University of Sussex, Brighton, United Kingdom.
Department of Neuroscience, Brighton and Sussex Medical School, Brighton, United Kingdom.
Front Psychiatry. 2019 Mar 5;10:29. doi: 10.3389/fpsyt.2019.00029. eCollection 2019.
Tourette syndrome is a hyperkinetic movement disorder. Characteristic features include tics, recurrent movements that are experienced as compulsive and "unwilled"; uncomfortable premonitory sensations that resolve through tic release; and often, the ability to suppress tics temporarily. We demonstrate how these symptoms and features can be understood in terms of aberrant predictive (Bayesian) processing in hierarchical neural systems, explaining specifically: why tics arise, their "unvoluntary" nature, how premonitory sensations emerge, and why tic suppression works-sometimes. In our model, premonitory sensations and tics are generated through over-precise priors for sensation and action within somatomotor regions of the striatum. Abnormally high precision of priors arises through the dysfunctional synaptic integration of cortical inputs. These priors for sensation and action are projected into primary sensory and motor areas, triggering premonitory sensations and tics, which in turn elicit prediction errors for unexpected feelings and movements. We propose experimental paradigms to validate this Bayesian account of tics. Our model integrates behavioural, neuroimaging, and computational approaches to provide mechanistic insight into the pathophysiological basis of Tourette syndrome.
抽动秽语综合征是一种运动亢进性疾病。其特征包括抽动，即反复出现的、被体验为强迫性和“不由自主”的动作；通过抽动释放得以缓解的令人不适的预感；以及通常能够暂时抑制抽动的能力。我们展示了如何从分层神经系统中异常的预测（贝叶斯）处理角度来理解这些症状和特征，具体解释如下：抽动为何会出现、其“非自愿”的本质、预感如何产生，以及抽动抑制为何有时会起作用。在我们的模型中，预感和抽动是通过纹状体躯体运动区域内对感觉和动作过度精确的先验信息产生的。先验信息的异常高精度是由皮质输入的功能失调性突触整合导致的。这些感觉和动作的先验信息投射到初级感觉和运动区域，触发预感和抽动，进而引发对意外感觉和动作的预测误差。我们提出了实验范式来验证这种关于抽动的贝叶斯解释。我们的模型整合了行为、神经影像学和计算方法，以深入了解抽动秽语综合征病理生理基础的机制。
