GSR amplitude instead of GSR magnitude: Caveat emptor!

Size of GSR made by 300 Ss to 20 repetitions of a visual stimulus is presented as mean magnitude and mean amplitude, illustrating that the amplitude method (averaging only those responses which are greater than zero) is susceptible to distortion resulting from a systematic elimination of Ss who initially make small responses. From trial to trial, the amplitude function comes more and more to be due to the behavior of Ss who initially make large responses. Even though the latter Ss’ responses actually reduce across trials, the amplitude function rises. Magnitude (including zeroes) docs not suffer from this distortion. It is suggested that the definition of a zero response is the source of the problem.     

Interest as a predeterminer of the GSR index of the orienting reflex

Participants in the experiment were selected from among the membership of three university recreational clubs, surfing, fishing, and chess. Participants were further restricted to those having an exclusive recreational interest. Sixteen students selected in this manner were shown slides depicting scenes related to each of the three interests as well as unrelated filler slides. Students displayed significantly larger GSRs to slides depicting their recreational interest as compared to the other recreations and the filler slides. Results were interpreted as reflecting the expression of an OR induced by a significant stimulus.     

On-line analysis of the GSR

This study reports the use of the λ, a measure of sequential dependency developed by Lathrop (1964) in connection with electrodermal activity. Thirteen female subjects, ranging in age from 19 to 53, participated in a simple repeat-stimulus habituation experiment: GSR data in percent-change and λ were compared. A high, positive correlation was obtained. Consequently, the use of λ is advocated because it shows both initial value and sequential dependency and meets the criteria for analysis based on the probability of statistics such ast andF.