The Presence of Deviant Tones Modulates Temporal Predictions in Visual-to-auditory Predictions

Forward predictions are not only crucial to predict somatosensory consequences of movements, but may also guide cross-modal sensory mapping (Ramnani, 2006). When a visual stimulus temporally predicts an auditory tone onset (‘when’ information), the amplitude of the N1-P2 complex is reduced compared to a temporally unpredictable tone (e.g., Ford et al., 2007; Sowman, Kuusik, & Johnson, 2012). However, cue quality and/or tone identity (‘what’ information) may further modulate visual-to- auditory predictions. When the quality of a visual cue varies, its strength to predict a subsequent tone onset influences cross- modal sensory mapping. In addition, infrequently occurring deviant tones (altered in frequency) induce uncertainty about tone identity that may further impact visual-to-auditory predictions (cf. Schwartze, Farrugia, & Kotz, 2013, for sensory predictions). A visual-to-auditory cross-modal prediction paradigm was used in the current experiment. Participants passively viewed visual cues that temporally predicted a subsequent tone onset or not. We manipulated (1) the predictive strength of a visual cue (five different cue colors vs. one [grey] color), (2) the probability of an auditory tone to occur (80% standard, 20% deviant tones), and (3) temporal predictability (predictable vs. unpredictable tone onset). Predictable blocks either preceded unpredictable blocks or vice versa (between subjects-design). This allowed investigating whether frequent standard tones are affected by uncertainty of tone identity (‘what’ information) as a function of temporal predictability (‘when’ information). The results on lateral electrodes revealed that the N1-P2 complex to standard tones was modulated by temporal predictability. The N100 amplitude was enhanced (predictable>unpredictable) when predictable blocks preceded unpredictable blocks, while the N100 amplitude was reduced (predictable