21. A method for obtaining eye-fixation duration data or eye-fixation duration and location data for testing the working memory of a patient using an eyetracking system comprising at least one video camera and at least one computer that is configured to measure and record the patient's eye-fixation data, the method comprising: a. presenting the patient with a verbal stimulus; b. presenting the patient with a first visual stimulus comprising a plurality of images wherein one of the images is a target image that corresponds to the verbal stimulus; c. presenting the patient with a second visual stimulus comprising an image to be remembered; d. presenting the patient with a recognition display comprising a plurality of images wherein one of the images corresponds to the second visual stimulus; e. measuring and recording eye-fixation duration data during steps a to d, wherein an eye fixation is a relatively stable position of the eye for a minimum duration of at least about 40 milliseconds with some slight tolerance in the vertical and horizontal dimensions; and f. analyzing the eye-fixation duration data to assess the patient's working memory.
25. The method in accordance with claim 21 , wherein the visual stimuli are presented on a computer screen.