[Human evoked potentials during perception of simple and complex visual stimuli].

Visual evoked potentials were recorded in children and juveniles with normal vision upon presentation of "blank" and checkboard patterns with different size of checkboard cells (10,20,40,60 and 120 angular minutes). A high degree of dependence was established both of early and later components on physical stimulus parameters: pattern structures (diffuse photic stimulus, checkboard pattern), the number of contrast borders (different sizes of checkboard cells). Maximal EP was recorded upon presentation of checkboard patterns with cells of 20 to 60 angular minutes. This is discussed as related to the size of receptive fields in man. Attraction and distraction of attention, while causing some amplitude changes mainly in later components (V and VII) amplitude did not considerably influence the EP configuration.