Objectives. To identify the characteristics of changes in the electroencephalogram (EEG) pattern and activation of neural networks on perception and performance of a motor act in healthy people and patients with affective disorders. Materials and methods. The study group consisted of 15 patients with affective disorders and the control group comprised 11 healthy subjects. The task was to first observe a hand movement performed by the experimenter (clenching of the fist), then to imagine this movement, and then to perform it themselves. EEG recordings were made and analyzed; areas of activation were identified by solving the reverse EEG problem using LORETA. Results and conclusions. Activation of the mirror system of the brain in patients with affective disorders was seen in the left temporal hemisphere, while healthy subjects showed activation in the temporal lobes of both hemispheres and the frontal superior, middle, and inferior gyri.