Figure 4.

Efficiency results for four auditory paradigms. Results shown are for contrast standard-deviant, TR = 0.842 and for an experiment duration of 900 s (i.e., 1,125 scans). Efficiency values are reported for “Classic oddball,” “Mixed Oddball35,” “Mixed Oddball37,” and “Roving oddball” with silence blocks of duration 7–10 s and in pseudorandomized order (ABBA). Whiskers corresponds to approximately +/−2.7σ and 99.3 percent coverage. We selected the “Mixed Oddball35” for its combination of high efficiency and the reduction of expectation achieved through the randomization of standard sounds.