Blinks and other ocular artifacts were corrected using the method of Gratton, Coles, and Donchin (1983). Trials with activity >100 µV were excluded from further processing. Averaged target waveforms were constructed separately for the easy and hard target conditions at each electrode site. P3 amplitude was defined as the point between 280 and 600 ms at which amplitude of the average waveform was maximal. Although there are different ways to capture P3 amplitude, we adopted this peak-in-window approach because a survey of studies exploring P3-AR’s relationship to externalizing spectrum disorders showed this to be the method of choice (Bauer & Hesselbrock, 2003; Brigham, Herning, & Moss, 1995; Chen et al., 2007; Enoch, White, Waheed, & Goldman, 2008; Hill, Locke, & Steinhauer, 1999; Hill, Muka, Steinhauer, & Locke, 1995; Iacono et al., 2002; Jones et al., 2006; M. S. Kim, Kim, & Kwon, 2001; Maurage et al., 2007; O’Connor, Bauer, Tasman, & Hesselbrock, 1994; Polich & Ochoa, 2004; Prabhu et al., 2001; Rangaswamy et al., 2007; Reese & Polich, 2003).Thus, our aim was to determine what TF analysis adds to the information yield derived from studies that have successfully identified P3-AR when measured this way.
