明るさ変化と色変化に対する視覚誘発脳波の非加法性

抄録

A study was made of visual evoked potentials (VEP's) elicited by heterochromatic stimuli. A periodic presentation of stimulus on a field of 2 degree of arc consisted of consecutive 500 msec duration of green, 12 msec of red or yellow, and 500 msec of green followed by 600 msec of dark. Averaged VEP's were recorded for 512 msec interval starting from the onset of the 12 msec red or yellow. Recordings were made for heterochromatic stimuli of equal lightness and unequal lightness. Recordings were also made for lightness induced potentials. The results revealed that the waveform of the VEP is strongly dependent on the lightness level and it is concluded that the assumption adopted for analyzing VEP's by several authors that VEP for an unequal lightness heterochromatic stimulus is linear summation of VEP's for the equal lightness heterochromatic stimuli and for the lightness stimuli may not be correct.