Shankar Swetha, Kayser Andrew S
Department of Neurology, University of California, San Francisco, California;
Center for Brain Imaging, New York University, New York, New York; and.
J Neurophysiol. 2017 Jun 1;117(6):2088-2103. doi: 10.1152/jn.00512.2016. Epub 2017 Mar 1.
To date it has been unclear whether perceptual decision making and rule-based categorization reflect activation of similar cognitive processes and brain regions. On one hand, both map potentially ambiguous stimuli to a smaller set of motor responses. On the other hand, decisions about perceptual salience typically concern concrete sensory representations derived from a noisy stimulus, while categorization is typically conceptualized as an abstract decision about membership in a potentially arbitrary set. Previous work has primarily examined these types of decisions in isolation. Here we independently varied salience in both the perceptual and categorical domains in a random dot-motion framework by manipulating dot-motion coherence and motion direction relative to a category boundary, respectively. Behavioral and modeling results suggest that categorical (more abstract) information, which is more relevant to subjects' decisions, is weighted more strongly than perceptual (more concrete) information, although they also have significant interactive effects on choice. Within the brain, BOLD activity within frontal regions strongly differentiated categorical salience and weakly differentiated perceptual salience; however, the interaction between these two factors activated similar frontoparietal brain networks. Notably, explicitly evaluating feature interactions revealed a frontal-parietal dissociation: parietal activity varied strongly with both features, but frontal activity varied with the combined strength of the information that defined the motor response. Together, these data demonstrate that frontal regions are driven by decision-relevant features and argue that perceptual decisions and rule-based categorization reflect similar cognitive processes and activate similar brain networks to the extent that they define decision-relevant stimulus-response mappings. Here we study the behavioral and neural dynamics of perceptual categorization when decision information varies in multiple domains at different levels of abstraction. Behavioral and modeling results suggest that categorical (more abstract) information is weighted more strongly than perceptual (more concrete) information but that perceptual and categorical domains interact to influence decisions. Frontoparietal brain activity during categorization flexibly represents decision-relevant features and highlights significant dissociations in frontal and parietal activity during decision making.
迄今为止，尚不清楚知觉决策和基于规则的分类是否反映了相似的认知过程和脑区激活。一方面，二者都将潜在模糊的刺激映射到一组较小的运动反应上。另一方面，关于知觉显著性的决策通常涉及源自嘈杂刺激的具体感官表征，而分类通常被概念化为关于潜在任意集合成员资格的抽象决策。以往的研究主要是孤立地考察这些类型的决策。在这里，我们在随机点运动框架中，通过分别操纵点运动连贯性和相对于类别边界的运动方向，在知觉和分类领域独立地改变显著性。行为和建模结果表明，与受试者决策更相关的分类（更抽象）信息比知觉（更具体）信息的权重更大，尽管它们对选择也有显著的交互作用。在大脑内部，额叶区域的血氧水平依赖（BOLD）活动能强烈区分分类显著性，而对知觉显著性的区分较弱；然而，这两个因素之间的相互作用激活了相似的额顶脑网络。值得注意的是，明确评估特征交互作用揭示了额顶叶分离：顶叶活动随两种特征都有强烈变化，但额叶活动随定义运动反应的信息的综合强度而变化。总之，这些数据表明额叶区域由与决策相关的特征驱动，并认为知觉决策和基于规则的分类反映了相似的认知过程，并且在它们定义与决策相关的刺激 - 反应映射的程度上激活相似的脑网络。在这里，我们研究当决策信息在多个不同抽象层次的领域中变化时，知觉分类的行为和神经动力学。行为和建模结果表明，分类（更抽象）信息比知觉（更具体）信息的权重更大，但知觉和分类领域相互作用以影响决策。分类过程中的额顶叶脑活动灵活地表征与决策相关的特征，并突出了决策过程中额叶和顶叶活动的显著分离。
