Effects of interstimulus interval length on short-and long-term habituation of autonomic components of the orienting response

The effects of two different interstimulus interval lengths (20-sec vs. 100-sec) on short- and long-term habituation of autonomic components of the orienting response (OR) were investigated in a study employing 24 subjects. Results indicated that the 20-sec interval length was associated with increased short-term habituation and decreased long-term habituation, relative to the longer, 100-sec interval length. There was also a statistically near-significant association between interval length and magnitude of the OR to a subsequently presented novel dishabituating stimulus. These results suggest the presence of two active habituation processes.