All association networks are bilateral with varied degrees of asymmetry.

Network estimates are illustrated for a representative individual from the discovery study (S12). The top row shows the anatomical topography of all 15 networks; rows I-IV highlight the four network groups examined. Note that all networks are bilateral, including the strongly lateralized networks LANG (left lateralized) and FPN-B (right lateralized). Figure S2 shows the quantitative lateralization for each network from the discovery sample of 14 individuals. DN-A, Default Network A; DN-B, Default Network B; LANG, Language; FPN-A, Frontoparietal Network A; FPN-B, Frontoparietal Network B; CG-OP, Cingulo-Opercular; SAL, Salience; dATN-A, Dorsal Attention A; dATN-B, Dorsal Attention B.

Association networks respond bilaterally in a task-specific manner.

The mean response is displayed for all participants from the discovery study for each of the association networks, separately for the left (L) and right (R) hemisphere regions. Lighter-shaded bars represent the left hemisphere, and darker-shaded bars represent the right hemisphere. Error bars show standard error of the mean. (Top) Both hemispheres of the LANG network are robustly activated by the Sentence Processing task contrast, even though the network regions in the left hemisphere are larger than those on the right (see Figure S2). (Bottom) Both hemispheres of FPN-A and dATN-A are robustly activated by the N-Back Load Effect task contrast, with more modest responses in FPN-B and SAL. Asterisks indicate significant positive responses. * = p < 0.05, ** = p < 0.01, *** = p < 0.001.

Association networks show lateralized responses for verbal versus nonverbal processing.

The mean response for the N-Back Face (nonverbal) > Word (verbal) task contrast is displayed for each of the association networks. Lighter-shaded bars represent the left (L) hemisphere, and darker-shaded bars represent the right (R) hemisphere. Error bars show standard error of the mean. Laterality effects are observed across 8 of the 9 networks, such that the left hemisphere of each network is preferentially recruited by verbal materials, while the right hemisphere is preferentially recruited by nonverbal materials. The effect spans all network groups. Bracketed asterisks indicate that the direct comparisons between the left and right hemisphere responses are significantly different. Asterisks by the bars indicate the individual bar’s response is significantly different from zero (positive in the right hemisphere, negative in the left hemisphere). * = p < 0.05, ** = p < 0.01, *** = p < 0.001.

Verbal versus nonverbal laterality effects extend widely across association cortex.

Maps of the laterality effect are shown for three representative individuals (Top Three Rows) as well as for the average group of participants (Bottom Row) from the discovery study. The N-Back Face (nonverbal; red/yellow) > Word (verbal; blue) task contrast is visualized as z-statistical maps on the inflated cortical surface. The data are shown unthresholded to facilitate complete visualization of the effect in each direction. Note that the left hemisphere is broadly responsive to words, and that the right hemisphere is broadly responsive to faces. This distributed pattern spans frontal, parietal, and temporal cortices. W, words; F, faces.

Association networks again respond bilaterally in a task-specific manner.

The mean response is displayed for all participants from the replication study for each of the association networks, separately for the left (L) and right (R) hemisphere regions. Lighter-shaded bars represent the left hemisphere, and darker-shaded bars represent the right hemisphere. Error bars show standard error of the mean. (Top) Replicating the discovery study, both hemispheres of the LANG network are again activated by the Sentence Processing task contrast, even though the network regions in the left hemisphere are larger than those on the right (see Figure S3). (Bottom) Both hemispheres of FPN-A and dATN-A are again robustly activated by the N-Back Load Effect task contrast, with more modest responses in FPN-B and SAL. Asterisks indicate significant positive responses. * = p < 0.05, ** = p < 0.01, *** = p < 0.001.

Prospective replication of lateralized responses for verbal versus nonverbal processing.

The mean response for the N-Back Face (nonverbal) > Word (verbal) task contrast is displayed for the a priori targeted association networks. Lighter-shaded bars represent the left (L) hemisphere, and darker-shaded bars represent the right (R) hemisphere. Error bars show standard error of the mean. The laterality effect was observed in each of the four targeted networks, such that the left hemisphere of each network is preferentially recruited by verbal materials, while the right hemisphere is preferentially recruited by nonverbal materials. The effect spans all network groups. Bracketed asterisks indicate that the direct comparisons between the left and right hemisphere responses are significantly different. Asterisks by the bars indicate the individual bar’s response is significantly different from zero (positive in the right hemisphere, negative in the left hemisphere). * = p < 0.05, ** = p < 0.01, *** = p < 0.001.

Verbal versus nonverbal laterality effects again extend widely across association cortex.

Maps of the laterality effect are shown for three representative individuals (Top Three Rows) as well as for the average group of participants (Bottom Row) from the replication study. The N-Back Face (nonverbal; red/yellow) > Word (verbal; blue) task contrast is visualized as z-statistical maps on the inflated cortical surface. The data are shown unthresholded to facilitate complete visualization of the effect in each direction. Note that the left hemisphere is again broadly responsive to words, and that the right hemisphere is responsive to faces. W, words; F, faces.