Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA; Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA.
Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA; McGovern Institute of Brain Research, Massachusetts Institute of Technology, Cambridge, MA, USA.
Neuroimage. 2021 Jul 15;235:117985. doi: 10.1016/j.neuroimage.2021.117985. Epub 2021 Mar 21.
Expectation can shape the perception of pain within a fraction of time, but little is known about how perceived expectation unfolds over time and modulates pain perception. Here, we combine magnetoencephalography (MEG) and machine learning approaches to track the neural dynamics of expectations of pain in healthy participants with both sexes. We found that the expectation of pain, as conditioned by facial cues, can be decoded from MEG as early as 150 ms and up to 1100 ms after cue onset, but decoding expectation elicited by unconsciously perceived cues requires more time and decays faster compared to consciously perceived ones. Also, results from temporal generalization suggest that neural dynamics of decoding cue-based expectation were predominately sustained during cue presentation but transient after cue presentation. Finally, although decoding expectation elicited by consciously perceived cues were based on a series of time-restricted brain regions during cue presentation, decoding relied on the medial prefrontal cortex and anterior cingulate cortex after cue presentation for both consciously and unconsciously perceived cues. These findings reveal the conscious and unconscious processing of expectation during pain anticipation and may shed light on enhancing clinical care by demonstrating the impact of expectation cues.
期望可以在很短的时间内塑造对疼痛的感知，但人们对感知期望如何随时间展开以及如何调节疼痛感知知之甚少。在这里，我们结合脑磁图 (MEG) 和机器学习方法来跟踪健康参与者（包括男女）对疼痛的期望的神经动力学。我们发现，通过面部线索 Conditioning 的疼痛预期可以从 MEG 中进行解码，最早在 cue 出现后 150ms，最晚在 cue 出现后 1100ms，但与有意识感知 cue 相比，对无意识感知 cue 进行解码需要更多的时间，并且衰减速度更快。此外，时间泛化的结果表明，解码基于线索的期望的神经动力学在 cue 呈现期间主要持续，但在 cue 呈现后很快消失。最后，尽管有意识感知 cue 引起的期望解码是基于 cue 呈现期间的一系列时间限制的脑区，但在 cue 呈现后，无论是有意识感知 cue 还是无意识感知 cue，解码都依赖于内侧前额叶皮层和前扣带皮层。这些发现揭示了疼痛预期过程中期望的有意识和无意识处理，并且通过证明期望线索的影响，可能为增强临床护理提供了线索。
