The reduced N1 to self-generated tones: an effect of temporal predictability?

Tones that are self-generated elicit a smaller N1 than externally triggered tones. Typically, however, self-generated tones are also more predictable in time than externally triggered ones. The present study investigated whether the attenuated N1 can be explained by predictability based on the temporal relationship between action and effect. Participants listened to tones that were self-generated by a key-press or preceded by a visual cue. The tones followed the key-presses or cues after a fixed (predictable context) or variable delay (unpredictable context). Tones triggered by a key-press elicited a smaller N1 than tones following a visual cue. This finding suggests that the reduced N1 to self-generated tones is not merely due to the fact that the tone's timing can be predicted based on its temporal relationship to the key-press. Whether a tone was presented in a predictable or an unpredictable context did not affect the N1.