The first finding, as reflected through spatial analyses, was that,compared with poor heartbeat perceivers, individuals with more accurate heartbeat perception reported more SPSs in some areas of the hand. There was also a difference between the two groups in terms of the topography of the SPSs intensity. Accuracy in heartbeat perception predicted not only the intensity of SPSs but also their overall and individual spatial extent and their variety. Finally, it also predicted the degree of confidence with which participants reported the location and extent of SPSs. These results definitely validate the hypothesis that interoception is one of the determinants of SPSs perception, as suggested via indirect evidence [2,3,27]. Interoception is not completely independent of attention oriented towards the self [8,13]. If, as suggested by
Matthias et al. [25], the ability to perceive internal signals such as heartbeats
accurately reflects one's ability to focus attention on one's self,
then this is the function the ability to focus on SPSs is based on. In fact,