The Brain Dynamics Center, Sydney Medical School and Westmead Millennium Institute, Acacia House, University of Sydney at Westmead Hospital, Sydney, NSW, Westmead 2145, Australia.
Neuroimage. 2010 Nov 15;53(3):918-25. doi: 10.1016/j.neuroimage.2010.01.084. Epub 2010 Feb 6.
Biases toward processing negative versus positive information vary as a function of level of awareness, and are modulated by monoamines. Excessive biases are associated with individual differences in mood and emotional stability, and emotional disorder. Here, we examined the impact of the catechol-O-methyltransferase (COMT) Val(108/158)Met polymorphism, involved in dopamine and norepinephrine catabolism, on both emotional brain function and self-reported negativity bias. COMT genotyping and self-reported level of negativity bias were completed for 46 healthy participants taking part in the Brain Resource International Database. Functional MRI was undertaken during perception of facial expressions of fear and happiness presented under unmasked (consciously identified) and masked (to prevent conscious detection) conditions. Structural MR images were also acquired. A greater number of COMT Met alleles predicted increased activation in brainstem, amygdala, basal ganglia and medial prefrontal regions for conscious fear, but decreased activation for conscious happiness. This pattern was also apparent for brainstem activation for the masked condition. Effects were most apparent for females. These differences could not be explained by gray matter variations. The Met-related profile of activation, particularly prefrontally, predicted greater negativity bias associated with risk for emotional disorder. The findings suggest that the COMT Met allele modulates neural substrates of negative versus positive emotion processing. This effect may contribute to negativity biases, which confer susceptibility for emotional disorders.
作为意识水平的函数，对负面与正面信息的处理存在偏见，并且受到单胺类物质的调节。过度的偏见与个体在情绪和情绪稳定性方面的差异以及情绪障碍有关。在这里，我们研究了儿茶酚-O-甲基转移酶（COMT）Val（108/158）Met 多态性（涉及多巴胺和去甲肾上腺素的分解代谢）对情绪大脑功能和自我报告的负面偏见的影响。为参与 Brain Resource International Database 的 46 名健康参与者完成了 COMT 基因分型和自我报告的负面偏见程度。在无意识识别（有意识地识别）和掩蔽（防止有意识地检测）条件下感知恐惧和幸福的面部表情时进行功能磁共振成像。还获取了结构磁共振图像。具有更多 COMT Met 等位基因的个体在大脑脑干，杏仁核，基底神经节和内侧前额叶区域中对有意识的恐惧表现出更高的激活，而对有意识的幸福表现出更低的激活。对于掩蔽条件下的脑干激活也存在这种模式。这种效果在女性中更为明显。这些差异不能用灰质变化来解释。与情绪障碍风险相关的激活的 Met 相关特征，特别是前额叶，预测了更大的负面偏见。研究结果表明，COMT Met 等位基因调节了负面与正面情绪处理的神经基础。这种影响可能导致负面偏见，从而增加了情绪障碍的易感性。
