Figure 4

Oscillatory and multi-scale entropy (MSE) differences in the left vs. the right hemispheric stimulation sites extracted from the pre-stimulus and delay period of the delayed word reading task from the pre-tDCS data. The comparisons are between stroke patients and controls. (A) Displaying the line plots of sample entropy and power spectral densities to visualize the differences in time scale-dependent signal complexity and spectral properties. With tDCS, we expected normalization of neuronal activity; the hypothesized directions of change are represented by red arrows. (B) Differences in mean oscillatory and MSE values between groups and between the stimulation sites. Asterisks (*) indicate significant interaction between group (stroke, controls) and stimulation site (left, right) at p < 0.05 from linear mixed models.