Functional connectivity of attention network related to individual differences in visual and proprioceptive weighting

Individual differences in the weighting of visual vs. proprioceptive cues during visuomotor reaching tasks are predictive of functional connectivity between visual and sensorimotor neural regions. When both visual and proprioceptive cues about target position are available (bimodal target), participants weight and integrate these signals to estimate target position. This weighting varies across individuals, with some relying more on vision and less on proprioception, and others vice versa. Neural excitability of the primary motor cortex, or M1, has been related to individual differences in visuo-proprioceptive recalibration, a process related to the individual weighting of proprioception and vision; and the primary somatosensory cortex, or S1, has been related to proprioceptive recalibration. Other preliminary work in our lab has shown increased neural synchrony between cerebellar and visual regions such as the fusiform gyrus and early visual cortex. Together, this evidence suggests that individual variation in unisensory visual and proprioceptive processes are related to variation in neural activity. Despite this evidence, the neural basis of these individual differences in visual and proprioceptive weighting remains unexplored. To measure neural activity related to individual differences in visual or proprioceptive weighting, we collected two resting state functional scans before and after participants performed a visuomotor reaching task. Using a seed-based network analysis, we found that the weight of vision versus proprioception was related to increased synchrony between the dorsal attention network seed in the right frontal eye field (contralateral to the left visual field where visual reach cues appeared) and M1, S1, and the superior parietal lobule, a region well known for its involvement in visual perception. This suggests the neural basis of individual biases for vision or proprioception may be regulated by attentional systems.