A geometrical factor in the variability of sensations of warmth evoked by radiation

Abstract

It is a commonplace observation in experiments on cutaneous sensation that a constant stimulus, applied under supposedly constant conditions, evokes a varial response. In this paper it will be shown that the variability is in part a geometri consequence of the fact that the sense organ is not a continuum but an aggregati of discrete, sensitive ‘spots’. The total extent of the ‘spots’ for one modality, acti at a given time, is only a small fraction of the area of the site tested; this is illustrat in all of the classical maps, and is particularly true of the warmth-spots (Rein (8)). I purposes of theoretical discussion, the sensory spots may therefore be treated points that form an array or pattern. This pattern is unlikely to be regular and mt indeed, be highly irregular. No assumptions about its regularity are necessary the present argument.