Skin Potential Level: Age and Epidermal Hydration Effects

Abstract

Age differences in skin potential level (SPL) of young adult and aged men were investigated using basal skin potential level (BSPL) procedures at three levels of epidermal hydration. A glycol medium was used at a site of least hydration. A distilled water and agar solution was the medium at two other more hydrated sites which also received either 0 min or 15 min pretreatment in distilled water. A 0.5% KCl electrolyte concentration was used at all sites. Significant effects for age and hydration were dependent on the point in the recording session comparisons were made. The major findings were: (1) the old men had significantly lower SPLs than did the young men at the start of recording with the glycol electrolyte medium; there were no significant age differences at the start of recording with the agar mediums, or at BSPL with any hydration condition. (2) Hydration significantly affected SPL magnitude at the start of recording, but not at BSPL. SPL recorded with the glycol medium at certain points in the recording was significantly related to outdoor activity among the aged men. This effect was independent of differences in cardiovascular status, and cardiovascular status was not significantly correlated with glycol SPL. It is concluded that there is a reduced sweat gland potential in old age which can only be observed when recording conditions produce high epidermal resistance. This reduced sweat gland potential is related to low levels of outdoor activity.

Influence of Relative Humidity on Electrodermal Levels and Responses

“…Concerning SP, although in average, SPL showed more negative value (Figure 2), some test subjects exhibit more negative levels and the remaining showed reduction in the negativity of SPL (Table 3) under the influence of high RH. The less negative SPL values were recorded in accordance with earlier reported measurements [12,[21][22][23][24][25]. These measurements confirm that SPL is negatively decreased (positive) when sweat glands are activated by means of skin hydration.…”

“…In addition, this might be due to the high humidity attributed to the inactivation of sweat glands. When there is no sweat gland activity such as in the case of a subject who is at rest, SPL mainly reflects the diffusion potential between epidermal and applied electrolytes [25]. In one way or another, these conflicting and interesting findings with explained reasons beside the skin types could be attributable to differences in subject habituation.…”

Electrodermal Activity

“…The authors explained their results with an increase in the epidermal potential component and a decrease in sweat gland potential in old age, which is a consequence of the sweat gland ducts' decay during aging. These findings were confirmed in another investigation by Garwood, Engel, and Kusterer (1981) with 25 young and 37 old male participants. Surwillo (1969), recording SP in 58 young (23-53 years) and 64 old (54-85 years) males during 15 min of an attention demanding task, revealed that mean SPLs were in the same range in both groups, fitting the normal distribution better in old as compared to young males.…”

Aging Effects of Sympathetic Reflex Activities on Skin Nerves

“…Garwood et al [9] found SSR amplitude after electrical stimulation to be decreased somewhat in older subjects. Baba et al [10] studied SSR reflex latency and amplitude following electrical stimulation; neither parameter differed significantly according to age.…”

“…However, to our knowledge, the aging effects on SSNA have not been reported. Many reports have previously reported the aging effects on SSR or SFR [9][10][11][12][13][14][15]17].…”