Stewart, M. A., Stern, J. A., Winokur, G., & Fredman, S. (1961). An analysis of GSR conditioning. Psychological Review, 68(1), 60-67.
http://dx.doi.org/10.1037/h0048816
Using the GSR, eyeblink, and startle responses one finds that almost no stimuli are neutral and hence "pseudoconditioning" must be guarded against. 19 student nurses were tested using shock to ankle as UCS, and 500 c/s tone as CS. The CR was found to occur between an orienting response to the tone and before response to shock. Criteria for defining tone conditioned GSR in terms of latency are described and reasons put forward for supposing that previous work has dealt with the adaptation and recovery of UCR's rather than conditioning of responses. (PsycINFO Database Record (c) 2016 APA, all rights reserved)