Correction: Application of an Adaptive, Digital, Game-Based Approach for Cognitive Assessment in Multiple Sclerosis: Observational Study. - Hsu, Wan-Yu; Rowles, William; Anguera, Joaquin A; Zhao, Chao; Anderson, Annika; Alexander, Amber; Sacco, Simone; Henry, Roland; Gazzaley, Adam; Bove, Riley (Journal of Medical Internet Research, 2021)