These would later be classified as components of the visual evoked response (VER), part of which includes the P2.

Visual evoked response or potential (VER or VEP), which is when the eyes are stimulated by looking at a test pattern.

The visual evoked response (VER) is the most commonly used evoked potential test in the diagnosis of multiple sclerosis (MS).

One of four subjects exposed to 1,000 ppm and two of four subjects exposed to 1,250 ppm for 7 hours demonstrated a statistically significant effect on the visual evoked response.

Buchsbaum and Fedio (1970), for example, reported that the visual evoked response to lateralised presentation of words and nonsense patterns differed for the two types of stimuli, most markedly over the left hemisphere.

In one experiment, visual evoked responses in the cortex were measured by displaying a white flash of light for 200 ms at various locations on a screen (the visual field); the flexible microelectrode array he created then recorded various patterns of neuronal activity based on the location of the flash on the screen.