Fig. 2: Inter- and intra-areal heterogeneity.

A We calculated the cosine distance between each pair of cortical areas and computed the mean value for each area. To identify cortical areas with the highest and lowest inter-areal dissimilarity, we conducted 1000 permutation tests⁶². Regions with significantly higher inter-areal dissimilarity compared to other areas after applying FDR correction were highlighted using black boundaries (p < 0.05). B The left panel illustrates the distribution of inter-areal dissimilarity across four cortical hierarchies. To examine differences between each cortical hierarchical level, two-sided two-sample t-tests were conducted with FDR correction (correlations with *: p_FDR < 0.05; correlations with **: p_FDR < 0.001). Sample sizes: Paralim (45), Hetero (75), Uni (79), and Idio (29); all are technical replicates. Box plots display the median (center line), interquartile range (box bounds =  25th to 75th percentiles), and whiskers extending to the minimum and maximum values within 1.5× the interquartile range (IQR). Bars are color-coded as follows: blue for paralimbic, orange for heteromodal, green for unimodal, and red for idiotypic. To explore associations with the histological gradient, two-sided Spearman’s correlation coefficients were computed (p = 0.001), and p values corrected using spin permutation tests⁶². C The gradient profile of parcel i was calculated by averaging the gradients across all vertices belonging to parcel i. The intra-areal dissimilarity of parcel i was then determined by calculating cosine distance between vertex-wise gradients and gradient profile of parcel i. By repeating this procedure for all parcels, we generated a map illustrating the distribution of intra-areal dissimilarity across the cortex. Regions with significantly higher intra-areal dissimilarity compared to other areas after applying FDR correction were highlighted using black boundaries (p < 0.05). D The distribution of vertex-wise intra-areal dissimilarity in four cortical hierarchies is shown in the left panel. To assess differences between each cortical hierarchy, two-sided two-sample t-tests were performed with FDR correction (correlations with *: p_FDR < 0.05). Sample sizes: Paralim (789), Hetero (2,342), Uni (2,403), and Idio (1779); all are technical replicates. Box plots display the median (center line), interquartile range (box bounds  = 25th to 75th percentiles), and whiskers extending to the minimum and maximum values within 1.5× the IQR. To explore associations with the histological gradient, two-sided Spearman’s correlation coefficient was computed with FDR correction. Source data are provided as a Source Data file. Abbreviation: Paralim Paralimbic, Hetero Heteromodal, Uni Unimodal, Idio Idiotypic.