Temporal judgments of immediate and delayed consequences of self-initiated movements

This study was designed to examine the impact of a delay between a self-initiated movement and a subsequent auditory event on temporal judgements of movement or sound onset. Participants watched a red dot move in a clockwise direction around a circle displayed on a computer screen and reported when they had pressed the spacebar or heard a tone. In other conditions, the movement and tone both occurred. Specifically, the tone followed the button press either immediately or after delays of 100, 250, or 400 ms. On some trial blocks, participants were asked to judge the time of the button press and on other blocks the time of the tone. When the tone occurred alone, participants' judgements were accurate. When the movement occurred alone participants exhibited an anticipatory bias. Although a delayed tone had a modest impact on judgements movement initiation, button press judgements were anticipatory in all tone delay conditions. Thusly temporal judgements associated with event binding are affected more by voluntary action than the auditory consequences of that action.