Department of Psychology and ASTAR-NUS Clinical Imaging Research Centre National University of Singapore Singapore.
Front Hum Neurosci. 2013 Aug 14;7:470. doi: 10.3389/fnhum.2013.00470. eCollection 2013.
Some chronic pain patients and healthy individuals experience pain when observing injury or others in pain. To further understand shared pain, we investigated perspective taking, bodily ownership and tooth pain sensitivity. First, participants who reported shared pain (responders) and those who did not (non-responders) viewed an avatar on a screen. Intermittently, 0-3 circles appeared. Sometimes the participant's and avatar's perspective were consistent, both directly viewed the same circles, and sometimes inconsistent, both directly viewed different circles. Responders were faster than non-responders to identify the number of circles when adopting a consistent perspective. Second, participants sat with their left hand hidden while viewing a rubber hand. All participants reported an illusory sensation of feeling stroking in the rubber hand and a sense of ownership of the rubber hand during synchronous stroking of the rubber and hidden hand. The responders also reported feeling the stroking and a sense of ownership of the rubber hand during asynchronous stroking. For experiment three, participants with either low, moderate, or high tooth sensitivity observed a series of images depicting someone eating an ice-popsicle. Low sensitivity participants never reported pain. In contrast, moderate and high sensitivity participants reported pain in response to an image depicting someone eating an ice popsicle (4 and 19% of the time, respectively) and depicting someone eating an ice-popsicle and expressing pain (23 and 40%, respectively). In summary, responders have reduced ability to distinguish their own and others' visual perspective and enhanced ability to integrate a foreign arm into their bodily representation. The tendency to share pain is also enhanced when an observed pain is commonly experienced by the observer. Shared pain may therefore involve reactivation of pain memories or pain schema that are readily integrated into a self perspective and bodily representation.
一些慢性疼痛患者和健康个体在观察到自身或他人受伤时会感到疼痛。为了进一步了解共有的疼痛，我们研究了同理心、身体所有权和牙齿疼痛敏感性。首先，报告共有的疼痛的参与者（应答者）和没有报告的参与者（非应答者）在屏幕上观看一个化身。间歇性地，会出现 0-3 个圆圈。有时参与者和化身的视角一致，双方都直接观察相同的圆圈，有时不一致，双方都直接观察不同的圆圈。当采用一致的视角时，应答者比非应答者更快地识别圆圈的数量。其次，参与者将左手藏起来坐在那里，同时观看一只橡胶手。所有参与者都报告说，当橡胶手和隐藏的手同步抚摸时，他们感觉到一种虚幻的抚摸感，并对橡胶手有一种所有权感。当橡胶手和隐藏的手异步抚摸时，应答者也报告说感觉到了抚摸，并对橡胶手有一种所有权感。对于实验三，牙齿敏感度低、中、高的参与者观察了一系列描绘某人吃冰棒的图像。低敏感度的参与者从未报告过疼痛。相比之下，中度和高度敏感的参与者在看到描绘某人吃冰棒（分别有 4%和 19%的时间）和描绘某人吃冰棒并表达疼痛（分别有 23%和 40%的时间）的图像时报告了疼痛。总之，应答者在区分自己和他人的视觉视角方面的能力降低，将外来手臂融入身体表现的能力增强。当观察者普遍经历观察到的疼痛时，共有的疼痛倾向也会增强。因此，共有的疼痛可能涉及到疼痛记忆或疼痛模式的重新激活，这些记忆或模式很容易被整合到自我视角和身体表现中。
