External location of touch is constructed post-hoc based on limb choice

Femke Maij; Christian Seegelke; W Pieter Medendorp; Tobias Heed

In touch, too, space is coded in several reference frames. Touch activates 25 specialized sensory receptors embedded in the skin, and the arrangement of the 26 peripheral sensors is reflected in the homuncular organization of primary 27 somatosensory cortex (Penfield & Boldrey, 1937; Roux et al., 2018) , referred to as 28 a skin-based or somatotopic layout. However, because our body can take various 29 postures, the stimulus location in space -often referred to as its external location 30 -must be derived by combining skin location and body posture, a process termed 31 tactile remapping (Heed, Buchholz, et al., 2015) . Indeed, there is evidence that 32 external tactile locations can be coded in a gaze-centered reference frame ( For touch, it has been suggested that the construction of spatial location is 49 an automatic process, implying that any tactile input is remapped into an external 50 code, irrespective of its relevance (Heed & Azañón, 2014; Röder et al., 2004) . The 51 most common experimental manipulation underlying this claim is limb crossing. 52