The palmar GSR, produced by electric shock to the forearm, was conditioned to a 1000 cps tone of 3 intensities: 35, 75, and 115 db. "The results showed that conditioning occurred only in the group receiving paired presentations of the 35 db CS and the shock UCS. The more intense CSs failed to be conditioned. Sensitization occurred in the groups receiving the 115 db CS, whether or not it was paired with shock. The results were interpreted as supporting Razran's theory of classical conditioning." (see 32: 2622) (PsycINFO Database Record (c) 2006 APA, all rights reserved)