探討情緒在預期影響痛覺之角色

Investigating the Role of Emotion in the Modulation of Expectations on Pain

張雨菲(Kulvara Lapanan)

指導教授 ： 曾明宗

國立臺灣大學/醫學院/腦與心智科學研究所/碩士(2021年)

https://doi.org/10.6342/NTU202101864

摘要

人類主要的感官經驗被認為是由預期與所接收到訊息互相交互作用而形成。儘管過去的研究皆指出，當大腦區域在調節疼痛時，感知功能與掌控情緒的大腦區域皆會被活化，例如眶額皮層（orbitofrontal cortex）和前扣帶皮層 (anterior cingulate cortex)。然而，到目前為止，情緒處理是否會影響疼痛調節仍不清楚。在本篇研究當中，我們採用功能性磁振造影（fMRI）來了解人類疼痛受到預期調節時扮演的角色。在本實驗中，我們使用視覺刺激以及情緒調節（重新評估）來操弄受試者的情緒。當實驗參與者預期到即將到來的疼痛刺激時，我們發現情緒調節策略能有效地減少負面和正面預期對痛覺調節的效應，且這兩種類型的預期效應包含不同的組成部分。我們發現負面預期包含情感和認知成分，而正面預期僅包含認知成分。當負面預期增痛的效果被情緒調節減少時，伴隨著右背前額葉皮質、右前扣帶皮質和左眶額皮質的活性減少，這表示這些區域可能構成負面預期的情感和認知成分。當正面預期減痛的效果被情緒調節減少時，伴隨著右背前額葉皮質活性增加，顯示此腦區可能構成正面預期的認知成分。這些實驗的結果顯示情緒對疼痛預期的作用在負面和正面的預期之間是不同的，增進了目前對人類疼痛認知調節的了解。

關鍵字

疼痛 ； 期望 ； 情感 ； 認知 ； 功能性磁振造影

並列摘要

Our subjective sensory experiences are thought to be shaped by interactions between expectations and incoming sensory information. Although previous studies have demonstrated that brain areas implicated in cognitive functions showed activation when expectations modulate pain, this process also produced activation within emotion-related brain areas, such as the orbitofrontal cortex and anterior cingulate cortex. To date, whether emotional processing has a role in pain modulation by expectations has yet to be explored. Here, we employed functional magnetic resonance imaging (fMRI) to investigate the role of emotion as well as cognition on pain expectancy in human. In a cue-based paradigm, we used a cognitive emotion regulation strategy (reappraisal) to manipulate participants’ affective and cognitive states when they anticipated upcoming painful stimuli. We found that this strategy effectively reduced both negative and positive expectancy effects, with both types of expectations encompassing dissimilar components. Negative expectations contained both affective and cognitive components, whereas positive expectations contained only cognitive components. When the effect of negative expectations to increase pain was reduced by emotion regulation, activation in the right dorsal prefrontal cortex, right anterior cingulate cortex, and left orbitofrontal cortex reduced, suggesting that these regions may constitute the affective and cognitive components of negative expectancy of pain. With regard to the positive expectation, we demonstrated an increase in activation within the right dorsal prefrontal cortex when its effect to reduce pain was decreased by emotion regulation, which indicates that the cognitive component of positive expectations may be represented in this region. Taken together, these findings suggest that the role of emotion on pain expectancy was different between negative and positive expectations, which enhances current understanding about cognitive modulation on pain in humans.

並列關鍵字

pain ； expectation ； emotion ； cognition ； fMRI

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