Ghio Marta, Cassone Barbara, Tettamanti Marco
Faculty of Mathematics and Natural Sciences, Heinrich Heine University Düsseldorf, Düsseldorf, Germany.
CIMeC-Center for Mind/Brain Sciences, University of Trento, Trento, Italy.
Imaging Neurosci (Camb). 2025 Feb 26;3. doi: 10.1162/imag_a_00484. eCollection 2025.
The recognition of manipulable objects results from the encoding of sensory input in combination with predictive decoding of experience-derived visuomotor information stored in conceptual-semantic representations. This grounded interpretative processing was previously found to subsist even under unaware perception of manipulable object pictures. In this fMRI study, we first aimed to extend this finding by testing whether experientially grounded visuomotor representations are unawarely recruited when manipulable objects are not visually depicted, but only referred to by words presented subliminally through continuous flash suppression. Second, we assessed the generalizability of decoding experience-derived conceptual information to other semantic categories, by extending our investigation to subliminally presented emotion words and testing for unaware recruitment of grounded emotion representations in the limbic system. Univariate analysis of data sampled from 21 human participants (14 females) showed that manipulable object words selectively activated a left-lateralized visuomotor network, both when words were presented below perceptual threshold and when participants subjectively reported lack of stimulus awareness. Emotion words selectively engaged the bilateral limbic network, although univariate analysis did not provide evidence for its recruitment under subliminal perceptual conditions. In turn, multivariate pattern analysis showed that neural codes associated with both manipulable object and emotion words could be decoded even in the absence of perceptual awareness. These findings suggest that the brain automatically engages in conceptual-semantic decoding of experience-derived information not only when circumstances require to interact with manipulable objects and emotions, but also when these referents are dislocated in time and space and only referred to by words.
对可操作物体的识别源于感觉输入的编码，以及存储在概念语义表征中的经验性视觉运动信息的预测性解码。先前发现，即使在对可操作物体图片无意识感知的情况下，这种基于经验的解释性处理依然存在。在这项功能磁共振成像（fMRI）研究中，我们首先旨在扩展这一发现，测试当可操作物体没有在视觉上呈现，而是仅通过连续闪光抑制下意识呈现的单词被提及时，基于经验的视觉运动表征是否会被无意识地调用。其次，我们通过将研究扩展到下意识呈现的情感词，并测试边缘系统中基于经验的情感表征的无意识调用，来评估将解码经验性概念信息推广到其他语义类别的可行性。对21名人类参与者（14名女性）采集的数据进行单变量分析表明，无论是单词在下意识阈值以下呈现，还是参与者主观报告缺乏刺激意识时，可操作物体单词都选择性地激活了左侧化的视觉运动网络。情感词选择性地激活了双侧边缘网络，尽管单变量分析没有提供在潜意识感知条件下调用该网络的证据。反过来，多变量模式分析表明，即使在没有感知意识的情况下，与可操作物体和情感词相关的神经编码也可以被解码。这些发现表明，大脑不仅在需要与可操作物体和情感进行交互的情况下，而且当这些指代物在时间和空间上错位且仅通过单词被提及时，都会自动对基于经验的信息进行概念语义解码。
