Accordingly, we posited that memory success effects are cognitively nonspecific in that they not only contrast successful with unsuccessful memory but are also sensitive to other cognitive and perceptual processes such as attention and task engagement. Likewise, theta power decreases and concurrent high frequency power increases (i.e. spectral tilt) are not only found in memory success contrasts, but also occur during audio-visual perception, hand movements, and arithmetic problem solving -- further suggesting that they represent a general biomarker of task engagement or attention.
