Effects of subject recruitment procedure on heart rate and skin conductance measures

This research was designed to determine whether the method employed to recruit subjects influences subsequent autonomic behavior. Skin conductance (SC) and heart rate (HR) measures were recorded from 60 female subjects equally divided among four groups which differed only with respect to the manner in which the subjects were recruited. The four groups employed included a volunteer group, a pay group, a subject-pool group, and a coerced group. Response comparisons were made between groups during a 10 min adaptation period followed by 20,5 sec bursts of 75 db white noise. Tonic levels and specific response magnitudes were scored for both SC and HR responses and, in addition, spontaneous SC activity was evaluated. Differences between the groups were observed in terms of HR and SC basal levels, and SC response magnitudes. The results supported the conclusion that autonomie behavior during a recording session is strongly influenced by subject recruitment procedure.