A method for assessing the navigational capacity in human subjects, and its use in diagnosing spatial disorientation in neurodegenerative diseases, such as, for example Alzheimer's disease. The method for assessing the navigational capacity includes conducting a spatial orientation test, recording the results of the test, analyzing the test results and making a determination of the navigational capacity of a human subject. In its most simple sense, navigational capacity includes the capacity not to get lost. The spatial orientation test includes various naturalistic navigation tasks that are each designed to assess specific areas of the navigational capacity of a subject.