The images of human working memory are coded by systems of cyclically repeating cerebral processes. The dominant frequency of the cyclical oscillations in an alpha rhythm focus, approximately 10 Hz, and the duration of the relative refractoriness after the impulse discharge of the neuron, approximately 0.01 sec, determine the diversity of the character of the bioelectrical activity of the human brain, and thereby determine the capacity and speed of working memory. The higher the frequency and the briefer the refractory state, the greater the capacity and the speed of memory. Methods for the assessment of both parameters on the basis of the individual characteristics of the human electroencephalogram in the state of its relative rest are indicated. Formulas are presented for the calculation of the capacity of memory and the duration of the operations of collation of images perceived and those stored in memory.