Relationship Between Vestibular Function and Topographic Memory

Inclusion Criteria: * Males or females of all racial and ethnic groups between the ages of 70 and 85 years of age; * Montreal Cognitive Assessment (MOCA) (http://www.mocatest.org) score of \>24; * No known history or current evidence of stroke, trauma, psychiatric illness, or other insult to the brain; * No current use of psychoactive medicine other than caffeine (100 mg/day) or alcohol (1-2 drinks per night); * Normal sleep (at least an average of 7 hours for four days prior to participation); * Able and willing to comply with study requirements including following instructions to complete vestibular and neuropsychological testing; and * Have full understanding of all elements of provide signature and dating of the written informed consent prior to the initiation of procedures specified in protocol. Exclusion Criteria: * \<70 or \>85 yrs of age; * MOCA score of \<25; * History, or current evidence, of stroke, trauma, psychiatric illness, or other insult to the brain; * Prior history of inner-ear balance problems; * Current use of psychoactive medicine other than moderate caffeine or alcohol use; * Acute or chronic sleep deprivation during the week prior to participation (\<7 hours/night on average for four nights prior to participation). Other Restrictions: * No alcohol use on the night before the vestibular testing * 7 hours minimum sleep the night before vestibular testing * No eye make-up can be worn on the day of the vestibular test due to possible interference with vestibular-ocular reflex testing apparatus