Public Health.

Background: With the advent of monoclonal antibody therapy to treat mild cognitive impairment and mild dementia due to Alzheimer's disease (AD) there is a need to develop tests to screen for neurocognitive difficulty that are reliable and easily deployed.

Method: The Rowan Digital Cancellation Tests (RDCT) is comprised of three tests administered using an iPad Pro. Each test was preceded by a practice trial. During practice and test trials a buzzer sounded when commission errors were made. For each test, participants worked for 180 sec. Sixteen targets were located in each quadrant. Target items were embedded within a random array modeled after Weintraub (2000). The Digital Letter Cancellation Test asked participants to circle the letter "A". The target for the Digital Symbol Cancellation was a geometric symbol. On the Digital Letter/Symbol Switching Cancellation test participants alternated first circling a specific letter, then a specific symbol. Five outcome variables were compiled including correct hits (range 0-64), distance per correct hit; mean non-motor/'think' time/hit; mean Apple pencil touch; and mean commission errors.

Result: A group of 21 community-dwelling participants were assessed (age = 51.9±7.2; education = 14.9±2.0; White = 66%, female = 91.5%). A graded pattern of performance was seen for most outcome variables (Table 1) such that more targets were identified for letter>symbol>letter/symbol (p< 0.003), and mean distance traveled per target was less for letter
Conclusion: Among this sample of community dwelling, generally healthy participants, the RDCT was well-tolerated. Preliminary data generally yielded graded pattern of performance based on test complexity. When brought to scale these tests could provide a reliable method to screen for neurocognitive decline among patients with neurodegenerative illness.