A computerized version of the CPT, used to assess response inhibition and adapted from Fallgatter et al. (1998), was administered to individuals from COGA's prospective study (Fallgatter et al. 1998). A total of twelve different letters (A, B, C, D, E, F, G, H, J, L, O, and X) were presented one at a time between two vertical lines as a fixation stimulus. There were 400 trials, where participants were shown the letters “O” and “X” 80 times each, and the other 10 letters 24 times each. Subjects were instructed to press a button when they saw an “X” right after an “O,” but to refrain from pressing the button when they saw an “X” after any other letter. Details regarding ERO processing procedures can be found in Supporting Information.
