Santos José Paulo, Seixas Daniela, Brandão Sofia, Moutinho Luiz
Superior Institute of Maia Maia, Portugal.
Front Neurosci. 2011 Jun 3;5:77. doi: 10.3389/fnins.2011.00077. eCollection 2011.
The ventromedial prefrontal cortex (vmPFC) is believed to be important in everyday preference judgments, processing emotions during decision-making. However, there is still controversy in the literature regarding the participation of the vmPFC. To further elucidate the contribution of the vmPFC in brand preference, we designed a functional magnetic resonance imaging (fMRI) study where 18 subjects assessed positive, indifferent, and fictitious brands. Also, both the period during and after the decision process were analyzed, hoping to unravel temporally the role of the vmPFC, using modeled and model-free fMRI analysis. Considering together the period before and after decision-making, there was activation of the vmPFC when comparing positive with indifferent or fictitious brands. However, when the decision-making period was separated from the moment after the response, and especially for positive brands, the vmPFC was more active after the choice than during the decision process itself, challenging some of the existing literature. The results of the present study support the notion that the vmPFC may be unimportant in the decision stage of brand preference, questioning theories that postulate that the vmPFC is in the origin of such a choice. Further studies are needed to investigate in detail why the vmPFC seems to be involved in brand preference only after the decision process.
腹内侧前额叶皮层（vmPFC）被认为在日常偏好判断以及决策过程中的情绪处理方面发挥着重要作用。然而，关于vmPFC的参与情况，文献中仍存在争议。为了进一步阐明vmPFC在品牌偏好中的作用，我们设计了一项功能磁共振成像（fMRI）研究，让18名受试者对积极、无差异和虚拟品牌进行评估。此外，我们还对决策过程期间和之后的阶段进行了分析，希望通过基于模型和无模型的fMRI分析，从时间上揭示vmPFC的作用。综合考虑决策前后的阶段，在将积极品牌与无差异或虚拟品牌进行比较时，vmPFC会被激活。然而，当将决策阶段与做出反应后的时刻分开来看，特别是对于积极品牌，vmPFC在做出选择后比在决策过程本身更活跃，这对一些现有文献提出了挑战。本研究结果支持这样一种观点，即vmPFC在品牌偏好的决策阶段可能并不重要，这对那些假定vmPFC是这种选择根源的理论提出了质疑。需要进一步的研究来详细调查为什么vmPFC似乎只在决策过程之后才参与品牌偏好。
