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Authors & Affiliations
Marlon Esmeyer, Timo Torsten Schmidt, Felix Blankenburg
Abstract
A major problem in identifying consistent neural markers underlying perceptual decision-making is that decisions are mostly inextricably linked to task-related confounds such as motor responses. By disentangling the choice content from choice direction and the physical response, we showed in prior studies that vibrotactile decision content is nevertheless most likely represented effector-specific (i.e. in brain areas associated to the required motor response). In the current study we used a visual adaptation of the delayed match-to-comparison task to test whether perceptual decisions would be represented similarly across different sensory modalities. With the task design, we rendered categorical choice-related signals independent of choice direction and response selection. To identify brain regions which contain choice-related information, we applied a multi-voxel pattern analysis (MVPA) whole-brain searchlight approach. We computed a conjunction analysis with the data from the prior vibrotactile study to test for cross-modal choice-signal specific activation. The MVPA revealed above-chance decoding accuracies in areas surrounding the left intraparietal sulcus (IPS) and the left premotor dorsal cortex (PMd), respectively (both at p < 0.05, FDR-cluster corrected). The conjunction analysis confirmed above-chance accuracies in the IPS (pFDR < 0.05) and in the PMd (p < 0.001, uncorrected). Our results indicate that categorical choice information contained in the IPS and the PMd is not only independent of common task confounds but can also be found across different sensory modalities. Overall, this supports the notion of a cross-modal, effector-specific representation of perceptual decisions.