The correlation between blood-oxygen-level dependent (BOLD) and local field potential (LFP) as a function of frequency.

(A) The correlation between electrocorticographic (ECoG) and BOLD for the V1 data shows a positive correlation between ECoG and BOLD for a broad range of frequencies, except those including the alpha changes. Gray lines represent the 9 individual V1 electrodes, the black line is the average, and the red line corresponds to the example sites shown also in Fig 7. (B) In the V2/V3 data, there was a strong negative correlation between ECoG and BOLD in the alpha range around 10 Hz and a positive correlation between ECoG and BOLD for a broad range of frequencies. Gray lines represent the 13 individual V2/V3 electrodes, the black line is the average, and the red line corresponds to the example electrode shown also in Fig 7. Note that neither the V1 electrodes nor the V2/V3 electrodes show a peak at the gamma frequency. (C) The correlation between LFP and BOLD for simulations fit to V1 shows that there is a positive correlation across most frequencies, except those including the alpha and gamma changes. (D) The correlation between LFP and BOLD for the simulations fit to V2/V3 shows that there is a strong negative correlation around 10 Hz and a positive correlation across a broad range of frequencies. (Code to download data and reproduce this figure can be found on https://github.com/dorahermes/Paper_Hermes_2017_PLOSBiology function ns_script10_Fig10.m).