SPATIAL SUMMATION OF COLD

In three experiments on the forearm, back, and cheek, respectively, the method of magnitude estimation served to reveal first-order descriptions of how the magnitude of cold sensation depends quantitatively on the strength of stimulation (degree of skin cooling) and on the areal size of stimulation. In all three regions, the magnitude of cold sensation turned out to depend almost as much on size as on amount of cooling, implying rich spatial summation in the cold modality. Although both warmth and cold modalities characteristically exhibit lavish spatial summation, they contrast in at least one important way: with warmth the contribution of field size relative to degree of warming progressively diminishes with ever higher levels of warmth (i.e., degree of summation declines), whereas with cold the relative contributions of size and degree of cooling tend to stay fixed. © 1979.