Analysis of the Structural-Functional Organization of a Counting Task in the Context of a Study of Executive Functions

fMRI data indicate that backward mental counting is accompanied by activation of structures in the left hemisphere: the supplementary motor area, the precentral gyrus, and the triangular part of the inferior frontal and inferior parietal gyrus, as well as the middle frontal gyrus on both sides. The literature indicates that each of these cortical activation zones is a component of the executive functions. The EEG response is highly diffuse. Its asymmetry and zonal concentration are apparent in the behavior of quantitative indicators of the individual frequency ranges. The greatest level of correspondence with the topography of fMRI responses is seen for increases in coherence in the EEG α2 and α3 ranges (9–12.5 Hz), especially in the prefrontal and anterotemporal areas of the left hemisphere. The aim of the present work was to analyze the cerebral structural-functional support of the “silent backward counting” task in healthy humans in the context of evaluating the state of executive functions. Complex EEG and fMRI investigations were conducted in eight healthy subjects aged 24 ± 3 years.