Competing programs shape cortical sensorimotor-association axis development

The cerebral cortex is organized along a dominant sensorimotor-to-association (S-A) axis, anchored by modality-specific primary sensorimotor areas at one end and transmodal association areas forming distributed networks that support abstract cognition at the other^1-11. The developmental mechanisms shaping this axis remain unclear^9-24. Here we present converging multispecies evidence supporting the multinodal induction-exclusion in network development (MIND) model, in which S-A patterning is governed by competing processes of induction and exclusion driven by two opposing transcriptomically defined programs. 'Pericentral' programs are induced around the frontotemporal poles, progress inwards toward the central regions of the undifferentiated neocortex and define higher-order association features. 'Central' programs are induced centrally through first-order sensorimotor thalamocortical inputs, establish primary areas and exclude pericentral programs. These conserved programs compete for space, resulting in compartmentalized expression of axon guidance, cell-cell adhesion, retinoic acid signalling, synaptogenesis, WNT signalling and autism-risk-associated genes. Notably, PLXNC1 and SEMA7A, a receptor-ligand pair representing pericentral and central programs, respectively, exhibit repulsive interactions between primary and higher-order association corticocortical axons. Induction and exclusion together establish an S-A organization in which primary areas emerge as focal islands within a broader ocean of distributed association networks. The MIND model provides a unifying framework for experimental, evolutionary and clinical phenomena, revealing induction and exclusion as antagonistic yet complementary principles shaping the S-A axis and processing hierarchies.