Film-Induced Positive Emotion Modulates Pain Perception and Pain-related Emotion: An MEG Study

• Main Authors: Yu-Chen Lan, 藍宇貞
• Other Authors: Li-Fen Chen
• Format: Others
• Language: en_US
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/61545988656713436153

碩士 === 國立陽明大學 === 腦科學研究所 === 99 === Introduction: Pain is an unpleasant experience and a disturbing problem. Previous studies demonstrated that positive emotional stimuli can decrease pain-related brain activities. In this thesis, we aimed at investigating how prolonged positive emotion modulates pain perception and subjective pleasantness by mapping brain activation using magnetoencephalography (MEG). Methods: Twenty-two healthy subjects (11 females; years 21 – 42) were recruited. Each subject was asked to watch a one-minute video clip (8 neutral and 8 comic in total) followed by receiving 5 laser stimulation (right hand) and verbally reporting pain intensity and pleasantness. MEG signals were recorded throughout the experiment. Repeated measures analysis of variance with Bonferroni post hoc test was used for the analysis of psychophysical data. A beamforming approach was employed to image the dynamic changes of cortical activity in a whole brain manner. Cortical-behavioral and inter-cortical correlation coefficients were estimated by Spearman rank correlation analysis. Results: The psychophysical results demonstrated the prolonged effect of the previous aroused positive emotion on subjective pleasantness after painful stimuli (p < 0.001). Pain intensity decreased when the subjects did not attend to painful stimuli (p < 0.01). In neuroimaging results, the prolonged effect of positive emotion was verified through decreased pain-evoked activity at the right ventrolateral prefrontal cortex, left insula, posterior cingulate cortex (PCC), superior temporal gyrus/temporo-parietal junction (STG/TPJ), and right caudate. The correlation results showed the positive correlation between pain intensity and STG/TPJ activity and pleasantness ratings positively correlated to the activity of PCC and caudate. Conclusions: Our results showed the prolonged effect of positive emotion on pain modulation. This is helpful for clinical patients who need to receive painful treatment/rehabilitation therapy. We can make good use of the waiting time before clinical treatment well by delivering some positive emotional stimuli. By doing so, we could expect that the patients’ pain perception and unpleasantness would decrease during the treatment for better clinical outcome.