Nonspecific Galvanic Skin Response and Respiration

Abstract

The nonspecific galvanic skin response ( G S R ) , i.e., a change in skin resistance unrelated to any known stimuli, has been attributed (Birch, 1963; Cohen, et al., 1960; Lacey 6: Lacey, 1958) to level of arousal mediated primarily by the reticular system. Though it is well known char changes in respiration ( R ) are relared to changes in heart rare ( H R ) , the relationship of R to the nonspecific GSR has nor been reported. In monitoring the early records in a study concerned with the relationship of EEG and autonomic nervous system ( A N S ) , six channels of EEG, plus H R , GSR, R , and skin temperature were recorded simultaneously. Changes in R were noted not only to be related to changes in H R but also to GSR responses which would be labeled nonspecific. TO determine whether R was a variable to be monitored with respectto changes in GSR, as well as HR, 10 early records from our young adult Navy helicopter pilots were examined. Five had marked nonspecific GSR activity over the 10-min. resting period sampled; 5 had no nonspecific GSR responses. Each S pair was matched with respectto rate of R before comparison was made of the coefficient of variation computed for each S for the time between each R cycle and for the depth of the inspiration, i.e., rate and depth of breathing. Also the percent of the nonspecific GSR responses that coincided with a change in R was computed. A nonspecific GSR was said to be related to a change in R if the cycle just before or during the GSR response was one SD above or below rhe mean R cycle rime or amplitude. The coefficient of variation for R time was larger for each of the five Ss with nonspecific GSR responses than for his matched control. Variability of amplitude was higher in three of the five. The agreement between the total 91 nonspecific GSR responses for the 5 Ss and changes in R was 76%. For Ss the percents were 88, 68, 75, 63, and 91. Thus the nonspecific GSR response is related in part to changes in R. Whether this is a causal relationship or due to a third factor, e.g., level of arousal, is yet to be determined.