Mesoscale synergy and redundancy in ferret sensory cortices during an audiovisual task

A major challenge in cognitive neuroscience is understanding how the spatiotemporal dynamics of neural activity of the cerebral cortex supports the processing of information about external stimuli and its use in forming accurate perceptual decisions. In particular, it is unclear how activity distributed across cortical areas and frequency bands encodes information synergistically or redundantly, and how these emergent properties of interactions across areas relate to perception. Here, we aim to measure synergy and redundancy during an audiovisual task at the mesoscale level in auditory, visual, parietal, and somatosensory areas in the ferret cortex. To address these questions, we recorded neural activity with 64-channel electrocorticographic arrays as trained ferrets performed a lateralized audiovisual detection task. We first utilized information theory to assess how stimulus information was encoded across frequency bands in sensory cortices. We found that stimulus information was predominantly encoded in theta and alpha band activity. Importantly, this information was larger in correct trials, indicating that its encoding is used for informing correct perceptual decisions. We then used Partial Information Decomposition to quantify whether different areas encoded stimulus-related information synergistically or redundantly. While both synergy and redundancy were observed during correct and incorrect perceptual choices within the theta band, redundancy was significantly greater than synergy, in both absolute and relative terms, during correct responses. These findings support the hypothesis that redundancy at the mesoscale level may be beneficial for behavioral accuracy.