Аннотация:Aim Few studies focused on the relations between brain pathologies and frequency-selective oscillations, extracted from the evoked potentials. The author's method - "Microstructural analysis of oscillatory brain activity" was used to study semantic categories of patients with Parkinson's disease (PD). This method identifies the frequency-selective generators in cortical and subcortical brain structures (Danilova, 2010). Material and methods 11 PD patients (4 males and 7 females, 64–79 years old, all right handed) with stages of disease (1 to 3 upon Hoehn-Yahr scale) and with monotherapy by levodopa were proposed a task of identification of semantic categories ("animals" or "objects"). Results The identification of the category - "animals" is selectively disturbed in patients with PD. But anticipation mechanism is preserved. Conclusion Disturbance of the category - "animals" in patients with PD is a significant pathological factor. Acknowledges. The study is founded by Russian Scientific Foundation project #14-18- 03253