Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.11.07.372805v1?rss=1 Authors: Voorhies, W. I., Miller, J. A., Yao, J., Bunge, S. A., Weiner, K. S. Abstract: While the disproportionate expansion of lateral prefrontal cortex (LPFC) throughout evolution is commonly accepted, the relationship between evolutionarily new LPFC brain structures and uniquely human cognitive skills is largely unknown. Here, we tested the relationship between variability in evolutionarily new LPFC tertiary sulci and reasoning skills in a pediatric cohort. A novel data-driven approach in independent discovery and replication samples revealed that the depth of specific LPFC tertiary sulci predicts individual differences in reasoning skills beyond age. These findings support a classic, yet untested, theory linking the protracted development of tertiary sulci to late-developing cognitive processes. We conclude by proposing a mechanistic hypothesis relating the depth of LPFC tertiary sulci to anatomical connections. We suggest that deeper LPFC tertiary sulci reflect reduced short-range connections in white matter, which in turn, improve the efficiency of local neural signals underlying cognitive skills such as reasoning that are central to human cognitive development. Copy rights belong to original authors. Visit the link for more info