Division of Systems Neuroscience of Psychopathology, Translational Research Center, University Hospital of Psychiatry, University of Bern, Bolligenstrasse 111, CH-3000 Bern 60, Switzerland.
Rhinology, Smell and Taste Outpatient Clinic, Department of Otorhinolaryngology Head and Neck Surgery, Bern University Hospital, Inselspital, Freiburgstrasse, CH-3010 Bern, Switzerland.
Neuroimage. 2015 Jul 1;114:120-7. doi: 10.1016/j.neuroimage.2015.03.048. Epub 2015 Mar 24.
Neural correlates have been described for emotions evoked by states of homeostatic imbalance (e.g. thirst, hunger, and breathlessness) and for emotions induced by external sensory stimulation (such as fear and disgust). However, the neurobiological mechanisms of their interaction, when they are experienced simultaneously, are still unknown. We investigated the interaction on the neurobiological and the perceptional level using subjective ratings, serum parameters, and functional magnetic resonance imaging (fMRI) in a situation of emotional rivalry, when both a homeostatic and a sensory-evoked emotion were experienced at the same time. Twenty highly dehydrated male subjects rated a disgusting odor as significantly less repulsive when they were thirsty. On the neurobiological level, we found that this reduction in subjective disgust during thirst was accompanied by a significantly reduced neural activity in the insular cortex, a brain area known to be considerably involved in processing of disgust. Furthermore, during the experience of disgust in the satiated condition, we observed a significant functional connectivity between brain areas responding to the disgusting odor, which was absent during the stimulation in the thirsty condition. These results suggest interference of conflicting emotions: an acute homeostatic imbalance can attenuate the experience of another emotion evoked by the sensory perception of a potentially harmful external agent. This finding offers novel insights with regard to the behavioral relevance of biologically different types of emotions, indicating that some types of emotions are more imperative for behavior than others. As a general principle, this modulatory effect during the conflict of homeostatic and sensory-evoked emotions may function to safeguard survival.
已经描述了由体内平衡失衡状态（例如口渴、饥饿和呼吸困难）引起的情绪和由外部感官刺激引起的情绪（例如恐惧和厌恶）的神经相关物。然而，当它们同时被体验时，它们相互作用的神经生物学机制仍然未知。我们使用主观评分、血清参数和功能磁共振成像（fMRI）在情感竞争的情况下研究了这种相互作用，即当同时经历一种体内平衡和一种感官诱发的情绪时。二十名高度脱水的男性被试者在口渴时对令人作呕的气味的评价明显不那么令人反感。在神经生物学水平上，我们发现这种口渴时主观厌恶感的降低伴随着脑岛皮层的神经活动显著减少，脑岛皮层是已知与厌恶感处理密切相关的大脑区域。此外，在饱足状态下体验厌恶感时，我们观察到对令人作呕的气味做出反应的大脑区域之间存在显著的功能连接，而在口渴状态下的刺激中则不存在这种连接。这些结果表明冲突情绪的干扰：急性体内平衡失衡可以减轻由潜在有害外部刺激的感官感知引起的另一种情绪的体验。这一发现为具有生物学差异的情绪类型在行为上的相关性提供了新的见解，表明某些类型的情绪比其他情绪对行为更重要。作为一般原则，这种在体内平衡和感官诱发情绪冲突期间的调节作用可能有助于保障生存。
