ABSTRACT
Our list is clearly in need of revision, but instead of extending it (which would presumably mean that our ‘sixth’ sense becomes our ‘tenth’ or ‘eleventh’), the solution has been to replace ‘touch’ with ‘somatosensation’. In this chapter, rather than offering a brief synopsis of each sense system, I have chosen to describe this multi-faceted sensory system in detail. This is not altogether an accident. First, in certain respects, somatosensation relies on the same sort of neural wiring as other senses, so it may serve as an approximate model for them too. Secondly, we know quite a lot about the neural wiring itself, which is somewhat less complex than the wiring of the visual system, for example. Moreover, we are beginning to realise that an understanding of how the brain responds to damage in this system may give an insight into the recuperative functions of the brain in other domains. Lastly, as we learn more about this system, psychological phenomena that we may, at one time, have attributed to our sixth sense or the power of mind-over-matter are finally yielding their secrets. Pain sensitivity and the phantom limb phenomenon are considered later in this chapter.
