Fig. 1: A data-driven analysis pipeline with Discovery and Replication samples that models the relationship between lateral prefrontal sulcal morphological features and reasoning performance.
From: Cognitive insights from tertiary sulci in prefrontal cortex
a An inflated cortical surface reconstruction of a right hemisphere from one example participant. Dotted white outlines show manually labeled sulci. Asterisks indicate the frequently omitted or misclassified tertiary sulci (Supplementary Fig. 1 for all participants). b Top: Example from the standardized test (modified from the original for display purposes) used to assess relational reasoning in this study (WISC-IV, Matrix reasoning task). In this task, participants are instructed to complete the matrix so that the relation between the two bottom shapes mirrors the relation between the two top shapes. In this example, option 4 completes the pattern. Bottom: Example from the processing speed task (WJ-R, Cross Out test), which serves as a behavioral control. In this task, participants are instructed to cross out all objects that match the object on the left as quickly as possible. c Feature selection—Discovery sample. A LASSO regression was performed in the Discovery sample to determine which sulci, if any, were associated with Matrix reasoning performance. The model parameters were fit iteratively using a leave-one-out cross-validation procedure (“Methods”). d Model evaluation—Replication sample. The sulci selected from the LASSO regression (orange; pmfs-iRH, pmfs-aRH, and pimfsRH) were included along with age in a model to predict task performance in the Replication sample. In order to assess the unique contribution of the selected sulci to task performance, this model (orange) was compared to two nested alternate models: (1) age alone (green) and (2) age in addition to all 12 labeled sulci (blue). All models were fit with a leave-one-out cross-validation procedure. pmfs-a: posterior middle frontal sulcus, anterior component; pmfs-i: posterior middle frontal sulcus, intermediate component; pmfs-p: posterior middle frontal sulcus, posterior component.
