Increased Attentive Use Is Linked to More Idiosyncratic Functional Connections.

Experience is thought to modify neural connections to adapt the network to be more optimal for the environment. Given the brain's complexity, multiple network changes could each move the system toward optimality. Standard approaches examine each connection independently; these studies have often shown considerable interindividual variability and modest effects (Marek et al., 2022). Here, we take a different strategy, determining how a whole-brain connection pattern differs from the typical pattern, that is, how "idiosyncratic" the pattern is. We examined how the idiosyncrasy of whole-brain connection patterns varies with frequency of the use of that part of cortex for attention-demanding tasks, focusing on central versus peripheral vision in healthy individuals (who use central vision more frequently for attention-demanding tasks). We found that the whole-brain pattern of functional connections to the cortical representations of central vision is idiosyncratic, whereas patterns of connections to representations of peripheral vision were very similar person to person in healthy vision controls (14 females, 9 males). In a second set of analyses, we examined the brains of people with central vision loss (11 females, 10 males) who use a portion of peripheral vision [the preferred retinal locus (PRL)] more frequently for attention-demanding tasks in their daily lives. The cortical representation of the PRL exhibits more idiosyncratic connections, compared with a control brain region or compared with the same brain region in matched healthy vision controls. These results are consistent with the hypothesis that increased attentive use of a brain area results in idiosyncratic patterns of whole-brain connections.