Uniphasic and diphasic wave forms of the skin potential response.

A Comparison of Skin Potential and Skin Resistance Responses as Measures of Emotional Responsivity

“…While the wave form of SP responses obtained in studies in this laboratory which have used shock as an unconditioned stimulus resemble those reported by Wilcott et al (1957), the responses obtained in the present study more closely resemble those reported by Fujimori (1956). The rapid initial negative defiection reported by Wilcott, the "jet-like" a response initiating a diphasic or polyphasic SP response, was not observed (Fig.…”

“…Section 1 depicts a typical SP response recorded in this study, and illustrates the scoring procedures employed. Section 2 shows the faster "jet-like" change found by Wilcott et al (1957) and others. Section 3 depicts a typical SR change in the present words would have resulted in partially canceling out the effect to be studied, as a steep gradient in raw scores would necessarily result in a large standard deviation, and therefore in a flattening of the gradient in standard scores (Epstein, 1962).…”

“…Recently, it has been suggested that the skin potential response merits further investigation because the qualitative differences in its wave forms may be of special significance. Thus, Fujimori (1955) reports that the polyphasic wave form normally occurs only in response to intense stimuli, and Wilcott et al (1957) report that & showing positive waves, either as part of a diphasic response or alone, are more apprehensive about the experimental situation than <Ss showing predominantly negative wave forms. Despite presumed advantages of obtaining skin potential responses, studies employing the endosomatic method are rare in the psychological journals.…”

“…Moreover, there are within, as well as between, *Ss, differences to contend with in recording the different SP wave forms. Thus, Wilcott et al (1957) describe a single S from whom four qualitatively different SP wave forms were recorded during one experimental session. There is currently no generally accepted procedure for treating the different wave forms independently, or for combining them into one over-all response.…”

PROBLEMS IN MEASUREMENT OF ELECTRODERMAL PHENOMENA—CHOICE OF METHOD AND PHENOMENA—POTENTIAL, IMPEDANCE, RESISTANCE1

“…As shown in three studies (1)(2)(3)(4) and more recently confirmed by others changes in all of these quantities (potential, resistance, and impedance) occur when the human subject is stimulated with a sensory stimulus such as electric shock and also when a more emergency type of reaction supposedly characteristic of the sympathetic autonomic nervous response is called out. Previous studies had shown each of the electrical characteristics separately, but it was demonstrated in these first three studies: (1) that two potential waves occur from each skin area (an "a" wave and a "b" wave); (2) that these two potential responses show non-sympathetic and sympathetic characteristics; (3) that resistance and impedance responses occur simultaneously with the potential responses.…”