Dalla Volta Riccardo, Fabbri-Destro Maddalena, Gentilucci Maurizio, Avanzini Pietro
Dipartimento di Scienze Mediche e Chirurgiche, Magna Graecia University, Viale Europa, Loc. Germaneto, 88100 Catanzaro, Italy; Dipartimento di Neuroscienze, University of Parma, Parma, Italy.
Brain Center for Social and Motor Cognition, IIT (Italian Institute of Technology), Parma, Italy.
Neuropsychologia. 2014 Aug;61:163-74. doi: 10.1016/j.neuropsychologia.2014.06.019. Epub 2014 Jun 21.
Different accounts have been proposed to explain the nature of concept representations. Embodied accounts claim a key involvement of sensory-motor systems during semantic processing while more traditional accounts posit that concepts are abstract mental entities independent of perceptual and motor brain systems. While the involvement of sensory-motor areas in concrete language processing is supported by a large number of studies, this involvement is far from being established when considering abstract language. The present study addressed abstract and concrete verb processing, by investigating the spatiotemporal dynamics of evoked responses by means of high density EEG while participants performed a semantic decision task. In addition, RTs to the same set of stimuli were collected. In both early and late time intervals, ERP scalp topography significantly differed according to word categories. Concrete verbs showed involvement of parieto-frontal networks for action, according to the implied body effector. In contrast, abstract verbs recruited mostly frontal regions outside the motor system, suggesting a non-motor semantic processing for this category. In addition, differently from what has been reported during action observation, the parietal recruitment related to concrete verbs presentation followed the frontal one. The present findings suggest that action word semantic is grounded in sensory-motor systems, provided a bodily effector is specified, while abstract concepts׳ representation cannot be easily explained by a motor embodiment.
人们提出了不同的观点来解释概念表征的本质。具身认知观点认为，在语义加工过程中，感觉运动系统起着关键作用，而更为传统的观点则假定概念是独立于感知和运动脑系统的抽象心理实体。虽然大量研究支持感觉运动区域参与具体语言加工，但在考虑抽象语言时，这种参与尚未得到充分证实。本研究通过在参与者执行语义决策任务时，借助高密度脑电图研究诱发反应的时空动态，探讨了抽象动词和具体动词的加工过程。此外，还收集了对同一组刺激的反应时间。在早期和晚期时间间隔内，事件相关电位（ERP）头皮地形图根据词类显著不同。根据隐含的身体效应器，具体动词显示顶叶-额叶网络参与动作。相比之下，抽象动词主要激活运动系统之外的额叶区域，表明该类别存在非运动语义加工。此外，与动作观察期间的报道不同，与具体动词呈现相关的顶叶激活晚于额叶激活。本研究结果表明，动作词语义基于感觉运动系统，前提是明确了身体效应器，而抽象概念的表征难以通过运动具身化来解释。
