Distributed network flows generate localized category selectivity in human visual cortex
Fig 5
Distributed activity flows account for the majority of localized selectivity to bodies.
(A) The activity flow mapping procedure (steps match Fig 2C) generating body responses in EBA/FBA (black), projected onto cortical schematics (right hemisphere). Green: source vertices excluded from analyses. Step 2 was not blacked out for visual comparison with step 4, however it was held out in-analysis. Step 4 color scale shows maximum of all regions’ mapped activations to body images for visual comparison with step 2. (B) The connectivity fingerprint [13,15] of the right EBA/FBA via rsFC (black lines). Radial lines: source regions connected to EBA/FBA, clustered by functional network assignments [25] (colored per legend; Fig 3C). 95% confidence interval: across participants. (C) Right EBA/FBA body selectivity: activity-flow-mapped (purple) and actual (coral). Gray dots: individual participants’ scores. Dashed line: no selectivity (1.0); used for comparison in statistical tests. Significant t-statistics are indicated with an asterisk (p<0.00001; see Methods). (D) Estimated contribution of distributed network interactions to body selective responses in EBA/FBA. (E) The activity flows (as in A3) of each source region contributing to mapped EBA/FBA responses to body images (statistical significance asterisks at network-mean level). (F) Variance explained by each network-restricted activity flow model (unmixed partial R2 in gray) of EBA/FBA’s response profile. Black lines: 95% confidence interval across participants. Asterisks: statistical significance versus each other network. E-F suggests that activity flowing over interactions with VIS2 and DAN represents a general network coding mechanism for EBA/FBA. See Methods for full details of each analysis.