THE ENCODING OF SENSORY INFORMATION AND EXPECTATIONS IN THE CEREBRAL PROCESSING OF PAIN

疼痛的作用是保护身体。为此，大脑将有关威胁的感觉信息转化为疼痛。然而，这种转换并不是线性的，而是受到个人期望的很大影响。这种预期效果代表着每一种疼痛治疗的重要组成部分。此外，期望可以显著促进慢性疼痛的发展和长期结果。然而，大脑如何在处理疼痛的过程中编码感觉信息和预期还没有完全了解。为了解决这个问题，我们将进行一系列脑电(EEG)实验。我们将建立在大脑功能和疼痛处理的最新预测编码概念的基础上，系统地评估大脑活动在发送感觉信息、预期、预测错误和疼痛感知信号中的作用。在四个实验中，将对50名健康的人类参与者施加实验性疼痛刺激，并对有害刺激强度和参与者对疼痛强度的预期进行独立操作。分析将应用最新的基于模型的功能成像方法来对脑电数据进行最先进的分析。利用脑电的高时间分辨率，我们将量化不同潜伏期和频率的大脑活动与刺激强度、预期(预测)、预测误差和这些元素的组合的编码之间的关系。不同实验的概要将展示这些关系如何概括为对感觉信息和期望的不同操纵。由于感觉信息和预期之间的相互作用是疼痛体验的核心，该项目承诺对疼痛的大脑机制有基本的见解。此外，由于感觉信息和预期的相互作用在慢性疼痛中经常发生改变，该项目有望进一步了解慢性疼痛的大脑机制。最后，由于期望显著影响疼痛治疗的治疗效果，该项目可能有助于理解和优化疼痛治疗。

Pain serves to protect the body. To this end, the brain translates sensory information about threat into pain. This translation is, however, not linear but substantially influenced by an individual’s expectations. Such expectancy effects represent an essential part of every pain treatment. Moreover, expectations can significantly contribute to the development and long-term outcomes of chronic pain. However, how the brain encodes sensory information and expectations in the processing of pain is not fully understood yet. To address this question, we will perform a series of electroencephalography (EEG) experiments. We will build upon recent predictive coding concepts of brain function and pain processing to systematically assess the role of brain activity in the signaling of sensory information, expectations, prediction errors and pain perception. In four experiments, experimental pain stimuli will be applied to 50 healthy human participants and noxious stimulus intensity and the participants’ expectations of pain intensity will be manipulated independently. Analyses will apply most recent model-based functional imaging approaches to state-of-the-art analyses of EEG data. Harnessing the high temporal resolution of EEG, we will quantify the relationship between brain activity at different latencies and frequencies and the encoding of stimulus intensity, expectations (predictions), prediction errors and combinations of these elements. The synopsis of the different experiments will show how these relationships generalize to different manipulations of sensory information and expectations. As the interaction of sensory information and expectations is at the heart of the pain experience, the project promises fundamental insights into the brain mechanisms of pain. Moreover, as the interaction of sensory information and expectations is often altered in chronic pain, the project promises to further the understanding of the brain mechanisms of chronic pain. Finally, as expectations significantly shape treatment effects in pain therapy, the project might help to understand and optimize pain treatment.