Table 1.

Design of experiment

	Modality
Timing	Action timing	Auditory timing
	Action nontiming	Auditory nontiming

The experiment employs a 2 × 2 factorial design with modality and timing as the experimental factors. The inclusion of the auditory control conditions allowed us to look for modulation that was driven by the need to perform time estimation using the cross-modal method, which were specific to actions but were not simply a general consequence of the timing process; this is picked out by testing the interaction of the two experimental factors.