Zani Alberto, Marsili Giulia, Senerchia Annapaola, Orlandi Andrea, Citron Francesca M M, Rizzi Ezia, Proverbio Alice M
Cognitive Electrofunctional Imaging Lab, Institute of Molecular Bioimaging and Physiology, National Research Council, Milan, Italy.
Milan Center for Neuroscience, University of Milan-Bicocca, Milan, Italy.
Biol Psychol. 2015 Jan;104:90-107. doi: 10.1016/j.biopsycho.2014.11.012. Epub 2014 Nov 29.
The aim of the present study was to investigate to what extent shared and distinct brain mechanisms are possibly subserving the processing of visual supra-categorical and categorical knowledge as observed with event-related potentials of the brain. Access time to these knowledge types was also investigated. Picture pairs of animals, objects, and mixed types were presented. Participants were asked to decide whether each pair contained pictures belonging to the same category (either animals or man-made objects) or to different categories by pressing one of two buttons. Response accuracy and reaction times (RTs) were also recorded.
Both ERPs and RTs were grand-averaged separately for the same-different supra-categories and the animal-object categories. Behavioral performance was faster for more endomorphic pairs, i.e., animals vs. objects and same vs. different category pairs. For ERPs, a modulation of the earliest C1 and subsequent P1 responses to the same vs. different supra-category pairs, but not to the animal vs. object category pairs, was found. This finding supports the view that early afferent processing in the striate cortex can be boosted as a by-product of attention allocated to the processing of shapes and basic features that are mismatched, but not to their semantic quintessence, during same-different supra-categorical judgment. Most importantly, the fact that this processing accrual occurred independent of a traditional experimental condition requiring selective attention to a stimulus source out of the various sources addressed makes it conceivable that this processing accrual may arise from the attentional demand deriving from the alternate focusing of visual attention within and across stimulus categorical pairs' basic structural features. Additional posterior ERP reflections of the brain more prominently processing animal category and same-category pairs were observed at the N1 and N2 levels, respectively, as well as at a late positive complex level, overall most likely related to different stages of analysis of the greater endomorphy of these shape groups. Conversely, an enhanced fronto-central and fronto-lateral N2 as well as a centro-parietal N400 to man-made objects and different-category pairs were found, possibly indexing processing of these entities' lower endomorphy and isomorphy at the basic features and semantic levels, respectively.
Overall, the present ERP results revealed shared and distinct mechanisms of access to supra-categorical and categorical knowledge in the same way in which shared and distinct neural representations underlie the processing of diverse semantic categories. Additionally, they outlined the serial nature of categorical and supra-categorical representations, indicating the sequential steps of access to these separate knowledge types.
本研究的目的是调查大脑的事件相关电位所观察到的视觉超范畴和范畴知识处理过程中,共享和不同的大脑机制可能在多大程度上发挥作用。还研究了获取这些知识类型的时间。呈现了动物、物体和混合类型的图片对。要求参与者通过按下两个按钮之一来判断每对图片是否属于同一类别(动物或人造物体)或不同类别。还记录了反应准确性和反应时间(RTs)。
对相同 - 不同超范畴以及动物 - 物体范畴分别进行了ERP和RTs的总体平均。对于更具内胚层特征的对,即动物与物体以及相同与不同类别对,行为表现更快。对于ERP,发现对相同与不同超范畴对的最早C1和随后的P1反应有调制,但对动物与物体范畴对没有。这一发现支持了这样一种观点,即在相同 - 不同超范畴判断过程中,纹状皮层中的早期传入处理可以作为分配给形状和基本特征不匹配(而非其语义精髓)处理的注意力的副产品而得到增强。最重要的是,这种处理增强的发生独立于传统的实验条件,即在各种处理源中需要选择性地关注一个刺激源,这使得可以设想这种处理增强可能源于视觉注意力在刺激范畴对的基本结构特征内和跨范畴对交替聚焦所产生的注意力需求。在N1和N2水平以及晚期正复合波水平分别观察到大脑对动物范畴和同类别对进行更突出处理的额外后部ERP反应,总体上最有可能与这些形状组更大内胚层特征分析的不同阶段相关。相反,发现对人造物体和不同类别对有增强的额中央和额外侧N2以及中央顶叶N400,这可能分别在基本特征和语义水平上指示对这些实体较低内胚层特征和同构性的处理。
总体而言,目前的ERP结果揭示了获取超范畴和范畴知识的共享和不同机制,就像共享和不同的神经表征是不同语义范畴处理的基础一样。此外,它们概述了范畴和超范畴表征的序列性质,表明了获取这些不同知识类型的顺序步骤。