Attentional Modulation of Brain Responses to Primary Appetitive and Aversive Stimuli

Studies of subjective well-being have conventionally relied upon self-report, which directs subjects¿ attention to their emotional experiences. This method presumes that attention itself does not influence emotional processes, which could bias sampling. We tested whether attention influences experienced utility (the moment-by-moment experience of pleasure) by using functional magnetic resonance imaging (fMRI) to measure the activity of brain systems thought to represent hedonic value while manipulating attentional load. Subjects received appetitive or aversive solutions orally while alternatively executing a low or high attentional load task. Brain regions associated with hedonic processing, including the ventral striatum, showed a response to both juice and quinine. This response decreased during the high-load task relative to the low-load task. Thus, attentional allocation may influence experienced utility by modulating (either directly or indirectly) the activity of brain mechanisms thought to represent hedonic value.

传统上，主观幸福感（subjective well-being）的研究多依赖自我报告法，该方法会引导被试关注自身的情绪体验。这类方法预设注意本身不会影响情绪过程，但这一预设可能引入抽样偏差。我们通过操纵注意负荷，结合功能磁共振成像（fMRI）检测被认为表征享乐价值的脑系统活动，以此检验注意是否会影响体验效用（experienced utility）——即逐刻的愉悦体验。实验中，被试在口服奖赏性溶液或厌恶性溶液的同时，分别执行低注意负荷或高注意负荷任务。包括腹侧纹状体（ventral striatum）在内的与享乐加工相关的脑区，对果汁与奎宁均产生了响应；且在高注意负荷任务时，该响应相较于低注意负荷任务时有所减弱。由此可见，注意分配可通过直接或间接调节被认为表征享乐价值的脑机制活动，来影响体验效用。