Abstract: The present invention provides an interactive method for testing the working memory of a test subject. The method includes displaying several encoded symbols randomly positioned on a video display for a predetermined period of time. The position of each encoded symbol corresponds to Cartesian coordinates on the video display. Each symbol has a predetermined priority that must be ascertained by the test subject based on recognized variables associated with each uncoded symbol. The symbols are deleted from the video display after expiration of the predetermined period. Then, unencoded symbols are displayed on the video display in the same pattern as were the encoded symbols so that there is a cardinal relationship between the Cartesian coordinates of the unencoded symbols and those of the encoded symbols. Each encoded and unencoded symbol having identical coordinates forms a symbol pair.