Prof. Tobias Heed | Touch in space: some thoughts on the reference frame debate

In the last 20 years, there has been a strong focus on showing that tactile input is transformed into a spatial code, or reference frame, that is compatible with the spatial coding of other sensory input. Many findings have been interpreted as showing automatic recoding of spatial location on the skin (“somatotopic”) into a 3D-like code (“external-spatial”). I will briefly review several studies of ours that refute this idea as a general principle underlying tactile processing. Yet, ironically, in some lines of tactile research the focus has been exactly opposite, with a strong claim that certain mechanisms are bound to the body’s anatomy, and I will refute those, too. The picture that emerges, then, is that multiple spatial codes are employed by our cognitive system, likely based on the task at hand and prior experience. I will offer some thoughts about how seemingly disparate findings may fit into a coherent framework based on models of state estimation and/or (spatial) prediction.