The process of distal attribution illuminated through studies of sensory substitution.

When we interact with objects in our environment, as a general rule we are not aware of the proximal stimulation they provide, but we directly experience the external object. This process of assigning an external cause is known as distal attribution. It is extremely difficult to measure how distal attribution emerges because it arises so early in life and appears to be automatic. Sensory substitution systems give us the possibility to measure the process as it occurs online. With these devices, objects in our environment produce novel proximal stimulation patterns and individuals have to establish the link between the proximal stimulation and the distal object. This review disentangles the contributing factors that allow the nervous system to assign a distal cause, thereby creating the experience of an external world. In particular, it highlights the role of the assumption of a stable world, the role of movement, and finally that of calibration. From the existing sensory substitution literature it appears that distal attribution breaks down when one of these principles is violated and as such the review provides an important piece to the puzzle of distal attribution.