The study employed a novelty oddball task (Friedman et al., 1993; Fabiani & Friedman, 1995) as detailed in two previous reports (Bruder et al., 2009; Tenke et al., 2010) using sounds developed at the Cognitive Electrophysiology Laboratory at NYSPI (Fabiani et al., 1996). Briefly, nontarget and target tones (300 ms duration, 350 Hz and 500 Hz frequency, 76% and 12% probability) interspersed with unique novel sounds (e.g., animals, musical instruments, etc.; 100–400 ms duration, 12% probability) were presented binaurally over headphones at 85 dB SPL in pseudorandom order (1000 ms stimulus onset asynchrony). A total of 400 trials were distributed over 8 blocks of 50 trials, each block consisting of 38 nontargets, 6 targets, and 6 novels. Participants were seated in a sound-attenuated booth and instructed to keep their eyes on a fixation cross during the task and to press a button as quickly as possible when, and only when, they heard the target tone. Response hand was counterbalanced across blocks. Participants were not informed about the novel sounds, and if they asked questions about their presence, they were reminded to respond only to the target tones.
