Do somatic markers need to be somatic? Analogies from evolution and from hardware interlocks

This paper considers Damasio's concept of the somatic marker from two new perspectives. The first of these considers them from the point of view of Dawkins's concept of the extended phenotype. This is used to develop the idea of the extended somatic marker, viz. a marker which uses some non-somatic feature of the external world in a similar fashion to the somatic marker. Secondly an analogy is developed with the concept of hardware interlocks in safety-critical systems. This is used to suggest why it is important that somatic markers are bodily states and not just mental markers.