Defining neurocognitive constructs underlying visual attention in mild cognitive impairment and dementia using...

BackgroundProblems with visual attention can be an early indication for the emergence of dementia.ObjectiveThe current research assessed visual attention using three iPad administered, digital cancellation tests.MethodsLetter and Symbol Cancellation Tests asked participants to circle a specific letter or symbol. On the Mixed Cancellation Test, participants alternated circling a letter, then a symbol. Five outcome variables were tallied: correct hits; mean intra-response pause or "think" time; mean drawing or "ink" time to circle correct hits; mean distance or search between correct targets; and commission errors. All but commission errors were expressed in four cumulative time epochs; 0-30 s, 0-60 s, 0-90 s, and 0-120 s. Using a protocol of paper/ pencil neuropsychological tests, Jak, Bondi criteria were used to classify 145 memory clinic patients into groups suggesting normal cognitive abilities (CL; n = 45); subtle or mild cognitive impairment (MCI; n = 62); and mild dementia (DEM; n = 38).ResultsFor correct hits and mean pause/ "think" time, the three groups were dissociated from each other at 60, 90, and 120 s. For mean drawing/'ink' time far fewer between-group differences were found. There was no difference across the three tests for mean search. On the Symbol and Mixed Cancellation Tests, MCI and DEM patients produced more commission errors than CL participants.ConclusionsFaster pause or "think time", perhaps reflecting better disengagement from circling target items, may underlie better cancellation test performance. When brought to scale, The Rowan Cancellation Tests could be an effective means to screen for MCI and emergent dementia.