Methods for diagnosing Autism and/or Autism Spectrum Disorder (ASD) of a subject include establishing baseline brain wave patterns of the subject by having the subject perform a series of task and measuring brain waves during the tasks using an EEG measurement device, applying a light stimulus or images to the subjects eyes and capturing eye movements and/or changes in facial expression in response to the light stimulus or images, and giving a neuropsychological and cognition battery of tasks to the subject to generate a provoked cognitive assessment of the subject. A processing device correlates the baseline brain wave patterns, eye movements and/or facial expressions, and provoked cognitive assessment of the subject to profile data indicative of Autism and/or ASD. The corresponding system may also include an auditory testing device that tests the subjects sensitivity to sound and records the subjects speech in response to verbal tasks. The processing device performs language processing of the recorded speech and correlates the processed language to the profile data indicative of Autism and/or ASD.
