The presented theoretical model explains three ways of epidermal hydra
tion changes. These ways are: water movement from both dermal layer an
d sweat gland ducts to the epidermis, and then, from the epidermis to
the air. Epidermal hydration changes influenced electrodermal activity
. It was revealed, that epidermal hydration changes impact both amplit
udes and latencies of the electrodermal activity.