Abstract
Conceptual knowledge is central to human cognition. Neuroimaging studies suggest that conceptual processing involves modality-specific and multimodal brain regions in a task-dependent fashion. However, it remains unclear (1) to what extent conceptual feature representations are also modulated by the task, (2) whether conceptual representations in multimodal regions are indeed cross-modal, and (3) how the conceptual system relates to the large-scale functional brain networks. To address these issues, we conducted multivariate pattern analyses on fMRI data. 40 participants performed three tasks—lexical decision, sound judgment, and action judgment—on written words. We found that (1) conceptual feature representations are strongly modulated by the task, (2) conceptual representations in several multimodal regions are cross-modal, and (3) conceptual feature retrieval involves the default, frontoparietal control, and dorsal attention networks. Conceptual representations in these large-scale networks are task-dependent and cross-modal. Our findings support theories that assume conceptual processing to rely on a flexible, multi-level architecture.
Competing Interest Statement
The authors have declared no competing interest.
Footnotes
In this revision, we have changed parts of the Introduction section to more clearly express our research question and the advantages of multivariate pattern analyses (MVPA) over univariate analyses for studying conceptual feature representations. Second, we have revised the Methods section to clarify the rationale and methodology of our MVPA searchlight and regions-of-interest (ROI) analyses. Third, we have performed an additional MVPA analysis in anatomical ROIs, which provides further support for task-dependent modulations of conceptual feature representations. Fourth, we have performed a supplementary analysis that relates the large-scale functional networks of Yeo et al. (2011) to the principal gradient of intrinsic connectivity (Margulies et al., 2016). Finally, we have thoroughly revised the Discussion section to address (1) the issue of modality-specific effects in the absence of an explicit conceptual task, (2) implicit effects of semantic category structure, and (3) previous MVPA studies of task- or context-dependent modulations of conceptual representations. We believe that these changes have substantially improved our manuscript.
