Authors
Stevens JC. Choo KK.
Institution
John B. Pierce Laboratory and Yale University, New Haven, CT 06519, USA.
JStevens@JBPierce.org
Title
Temperature sensitivity of
the body surface over the
life span.
Source
Somatosensory & Motor Research. 15(1):13-28, 1998.
Abstract
Detection thresholds to warming and cooling were measured in 13 regions of
the body in 60 adults aged between 18 and
88 years. From these thresholds were constructed maps of
thermal sensitivity homologous to
body maps of spatial acuity (in the older
literature two-point discrimination), long known to the
somatosensory scientist. Maps of cold and warm sensitivity
for young, middle-aged and elderly adults, show how
sensitivity changes with age in the various
body regions. Three characteristics emerge, irrespective of
age: (1) sensitivity varies approximately 100-fold over
the body surface. The
face, especially near the mouth, is exquisitely sensitive,
the extremities, by comparison, poor, other
regions, intermediate. (2) All body regions are more
sensitive to cold than to warm. (3) The better a region is
at detecting cold, the better it is at detecting warm. With
age, thermal sensitivity declines.
The greatest changes take place in the
extremities, especially the foot, where thresholds often
become too large to measure. Central regions give up their
sensitivity with age more slowly, and even (as in
the lips) inconsequentially. Similar age-related changes
have also previously been shown to characterize spatial acuity.