Accordingly, the disposition theory has a very different account of what is happening with sensory substitution devices than Susan Hurley and Alva Noë (see Section 2.3.2 above). On the disposition theory, what allows the user of such a device to have spatial experience is not the ability to anticipate how the sensory input will change upon execution of movement as the sensorimotor contingency theory would have it. Rather, it is that the subject’s brain has learned to take these sensory inputs together with postural signals to produce sets of basis functions that poise the subject to act with respect to the object that is causing the sensory signals (see Grush 2007: 406).