Forty-eight college students, after serving as Ss in a SRR discrimination conditioning experiment, were divided into quartiles on magnitude of SRR to both noxious (UCS) and innocuous (CS) stimuli. With both orienting response (OR) measures, i.e. to the CS and to the UCS, it was shown that subjects giving large ORs gave significantly larger responses to both CS+ and CS− (during conditioning) than did Ss giving small ORs. On the basis of the innocuous stimulus split, Ss giving large ORs demonstrated both significantly faster and greater discrimination conditioning than did Ss giving small ORs. Such differences in rate and amount of discrimination conditioning were not demonstrated with the noxious stimulus split. In other words, with the noxious stimulus measure there is only a significant response level effect, but with the innocuous stimulus definition of OR, there is a significant response level effect, and a significant effect on rate and amount of discrimination conditioning. Thus, noxious and innocuous stimulus definitions of OR do not appear to be measuring the same process.