Object, intensity and subject variables in visual evoked response

10 subjects were studied to determine AEP effects of square, circle, and black stimuli with variable stimulus intensity. For the group as a whole, object and intensity effects were significant on a number of amplitude and latency measures, but the object effect appears largely to reflect the presence or absence of a figure, rather than its nature. Increased intensity differentially affected latency, shortening the first negative deflection while lengthening the second positive. Amplitude is generally increased with higher intensity. Analysis of within subjects effects showed considerable variability as to which parameters were significantly related to the independent variables in individual subjects. A repeated measures, within subjects research strategy is seen as appropriate on the basis of these data.