Fig. 2: Lateral prefrontal tertiary sulci are identifiable and show comparable patterning across hemispheres and samples in children and adolescents.

a Lateral prefrontal (LPFC) sulcal definitions on inflated cortical surface reconstructions from six example participants (P1, P3, etc.) in the Discovery sample (top) and the Replication sample (bottom). Sulci were identified based on the most recent neuroanatomical atlas to consider a comprehensive definition of tertiary sulci²⁶. Primary sulci (1–8) are in blue, while tertiary sulci (9–12) are in orange. The three tertiary sulci (pmfs-i_RH (10), pmfs-a_RH (11), and pimfs_RH (12)) identified by our model-based approach with cross-validation (Fig. 4) are filled in. The distinction among primary, secondary, and tertiary sulci is based on classic and recent studies examining the timepoints when sulci emerge in gestation (“Methods” and Supplementary Information). Based on these studies, the sulci considered in the present work are either primary or tertiary (Supplementary Information). b Rates of intersection with surrounding sulci were quantified for each tertiary sulcus in the left (LH) and right (RH) hemispheres in order to identify common sulcal patterns. For each tertiary sulcus (pmfs-p (9), pmfs-i (10), pmfs-a (11), and pimfs (12)), we report the proportion of intersection (frequency of occurrence/total number of observations) with each LPFC sulcus (see color bar for reference; empty gray cells in the matrix reflect the fact that a sulcus cannot intersect with itself). Calculating the correlation between matrices shows that sulcal patterning is comparable (all rs > 0.70; all ps < 0.0001) between hemispheres and samples. Source data are provided as a Source data file.