Cognitive Neuroscience Sector, International School for Advanced Studies, 34136 Trieste, Italy.
J Neurosci. 2011 May 25;31(21):7763-74. doi: 10.1523/JNEUROSCI.4579-10.2011.
Despite the recent interest in the neuroanatomy of inductive reasoning processes, the regional specificity within prefrontal cortex (PFC) for the different mechanisms involved in induction tasks remains to be determined. In this study, we used fMRI to investigate the contribution of PFC regions to rule acquisition (rule search and rule discovery) and rule following. Twenty-six healthy young adult participants were presented with a series of images of cards, each consisting of a set of circles numbered in sequence with one colored blue. Participants had to predict the position of the blue circle on the next card. The rules that had to be acquired pertained to the relationship among succeeding stimuli. Responses given by subjects were categorized in a series of phases either tapping rule acquisition (responses given up to and including rule discovery) or rule following (correct responses after rule acquisition). Mid-dorsolateral PFC (mid-DLPFC) was active during rule search and remained active until successful rule acquisition. By contrast, rule following was associated with activation in temporal, motor, and medial/anterior prefrontal cortex. Moreover, frontopolar cortex (FPC) was active throughout the rule acquisition and rule following phases before a rule became familiar. We attributed activation in mid-DLPFC to hypothesis generation and in FPC to integration of multiple separate inferences. The present study provides evidence that brain activation during inductive reasoning involves a complex network of frontal processes and that different subregions respond during rule acquisition and rule following phases.
尽管最近人们对归纳推理过程的神经解剖学产生了兴趣，但前额叶皮层（PFC）中与归纳任务相关的不同机制的区域特异性仍有待确定。在这项研究中，我们使用 fMRI 来研究 PFC 区域对规则获取（规则搜索和规则发现）和规则遵循的贡献。26 名健康的年轻成年参与者被呈现一系列卡片图像，每张卡片上都有一组按顺序编号的圆圈，其中一个圆圈被涂成蓝色。参与者必须预测下一张卡片上蓝色圆圈的位置。必须获取的规则与后继刺激之间的关系有关。受试者的反应被分为一系列阶段，要么是在规则获取期间（规则发现之前和包括规则发现的反应），要么是在规则遵循期间（规则获取后的正确反应）。背外侧前额叶皮层（mid-DLPFC）在规则搜索期间活跃，并在成功获取规则后仍然活跃。相比之下，规则遵循与颞叶、运动和内侧/前前额叶皮层的激活有关。此外，额极皮层（FPC）在规则获取和规则遵循阶段之前一直活跃，直到规则变得熟悉。我们将 mid-DLPFC 的激活归因于假设生成，将 FPC 的激活归因于多个单独推断的整合。本研究提供的证据表明，归纳推理过程中的大脑激活涉及到一个复杂的额叶过程网络，并且不同的子区域在规则获取和规则遵循阶段都会做出反应。
