Cognitive function will be assessed during screening using the Montreal Cognitive Assessment (MoCA), participants must score >18 to be eligible. We will also assess psychomotor speed, attention, and working memory using the Digit Symbol Substitution Test (DSST). Participants are given a series of numbered symbols and then asked to draw the appropriate symbols below a list of random numbers. The score is the number of correctly made matches in 2 minutes (120 seconds). The cognitive function tests will be audio recorded by the assessor using a hand held digital recorder. The recordings will be used to properly score the tests as well as be available for quality control testing. The recordings will be deleted once the study is over and the data that was entered has been verified.