Figure 2.

Autocorrelation function and intrinsic cortical neural timescales at baseline. A, Average autocorrelation function at baseline across electrodes and patients, for electrodes in the temporal (pink) and entorhinal (light blue) cortices, hippocampus (orange), and amygdala (green). The autocorrelation shows a significant main effect of region for time lags between 10 and 80 ms (horizontal solid bar). Dashed horizontal line at 1/e (inverse of natural logarithm) indicates the value of the autocorrelation for which the characteristic timescales are extracted. B, Intrinsic timescales at baseline (τ), plotted for each electrode, show a main effect of region, with significantly faster timescales for the temporal and entorhinal cortices compared with the hippocampus and amygdala. C, The spatial organization of intrinsic timescales follows the cortical anatomy. Electrodes in the posterior/superior temporal cortex exhibit the fastest timescales, which progressively increase along the anterior/inferior axis. Color map represents the intrinsic timescale for each electrode on a logarithmic scale. For display purposes, all electrodes were projected to the left hemisphere. D, Gradients of timescales spanning the cortex, plotted as timescales along the X, Y, and Z directions of MNI coordinates of each electrode. Timescales significantly correlate with MNI coordinates in all three dimensions, tracking the cortical anatomy.