Decomposing electrocorticographic (ECoG) data into three summary components.

(A) A schematic to show the summary metrics derived from ECoG spectra: broadband power elevation (bb), narrowband gamma (ϒ), and alpha (α). Broadband was calculated by the increase in a 1/fⁿ signal, gamma was calculated by fitting a Gaussian on top of the 1/fⁿ line, and alpha was calculated as the difference from baseline in the alpha-frequency range. (B) Power spectrum for one example electrode during a blank stimulus (black), gratings (red), and noise patterns (blue). (C) From the power spectrum, changes in broadband, gamma, and alpha were calculated. These values were bootstrapped 100 times across trials. Error bars represent 68% confidence intervals. (code to download data and reproduce this figure can be found on https://github.com/dorahermes/Paper_Hermes_2017_PLOSBiology function ns_script03_Fig3.m).