This technology uses quantification of binocular rivalry as a diagnostic biomarker for ASD in animals and humans. Binocular rivalry is a visual phenomenon that occurs when each eye is shown a separate image. During binocular rivalry the brain switches between perceiving the right eye image, left eye image, or a merge of the two images at once. Previous studies have shown that patients with ASD have significantly slower cycling between these states, and spend more time in the merged image state than normal controls. However, these previous studies relied on self-reporting of perception, which requires verbal instruction. This invention uses a combination of visual stimulus along with EEG measurements of brain activity to determine if the brain is perceiving the right image, left image, or both, thereby eliminating the need for patient interaction in the test. This technology can effectively measure the increased merged image perception and lowered switching frequency found in ASD patients compared to healthy controls. Additionally, this technology is suitable for both animals and humans. This technology is reproducible over many tests and can therefore be used to track patients over time or in response to different drug treatments.