Table 1. Predictions of three different accounts.

Which plays a dominant role in repeated adaptation? Attention or habituation?	Adapter is passively viewed		Adapter is attended with a demanding task
	Prediction	Data	Prediction	Data
Only attention	AE reduces	Yes	AE increases	No
Only habituation	AE reduces	Yes	AE reduces	No
Both attention and habituation	AE reduces	Yes	All is possible	Yes

Note: AE represents perceptual aftereffects.