Figure 5.

Time-frame by time-frame sLORETA results (2). Principal sLORETA results obtained when considering a time-frame by time-frame analysis performed with log of F-ratio and comparing real TMS minus sham conditions. Images are plotted with respect to the time windows identified in a butterfly plot of the evoked potentials obtained from the real TMS condition. (A) Results obtained in the 61–65 ms time window and results obtained 199 ms after the delivery of TMS. Activations with the maximal peak in the left middle frontal gyrus (BA 6) are shown. (B) Results obtained in the 88–90 ms time window. Activation with the maximal peak of activation in the left superior frontal gyrus (BA 10) is shown. The time course of the intensity of the signal in the source space is also shown. Real TMS signals for a specific peak (corresponding to a specific voxel) are indicated by a blue line (standard deviations are indicated by shadows of the same color). Sham signals for the same peak (and voxel) are indicated by a red line (standard deviations are indicated by shadows of the same color). The corresponding significant time-frames are indicated by gray shadows. It is very important to note that the intensity of the signal in the source space has, here, the form of an F-statistic, since sLORETA perform the standardized estimate of the cortical current density, expressed as a statistical value (F-distribution value; Pascual-Marqui, 2002). It has negative values because they are the logarithmic transformation of source activation estimates.