Ordinarily from custom and habit in the suppression of feelings we notice none of these contact sensations with their almost inevitable itchy and ticklish feelings, though they are constantly there, but we can reveal them to ourselves by thinking definitely about any part of the body. Such concentration of attention at once brings that part of the body above the threshold of consciousness, and we have distinct feelings there that we did not notice before. If for instance we think about the big toe on the left foot, immediately our attention is turned to it and we note sensations in it that were quite unnoticed before. We can feel the stocking touching any part of it {128} that we think of. Not only that, but if we concentrate attention on a part most uncomfortable sensations develop. If anything calls our attention even to the middle of our backs, we find at once that there is a distinct sensation there, and this may become so insistent as to demand relief. It is well understood now what happens in these cases. As we have said, the attention given to a part leads to a widening of the minute blood vessels located there so that the nerve endings to the part are supplied with more blood and therefore become more sensitive. We know from experience in cold windy weather that when the cheek is hyperaemic the drawing of a leaf or even of a piece of paper across it may produce a very acute painful sensation. Hyperaemia always makes parts of the body much more sensitive than before. Attention has just this effect over all the surface of the body, as we can demonstrate to ourselves. We can actually, though only gradually, make our feet warm by thinking about them, because the active attention to them sends more blood to them. The dread of pain then, by concentrating attention on the part beforehand, actually increases the pain that has to be suffered and makes the subject {129} ever so much more sensitive. Sensitiveness is of course dependent on other factors, as for instance lack of outdoor air and of oxygenization, which actually seems to hypersensitize people so that even very slight pain becomes extremely difficult to bear, but the question of attention, which is after all almost entirely a voluntary matter, has more to do with making pain harder to bear than anything else.