Figure 6.2.
Effects of response-contingent, yoked, or continuous nicotine or responding for VS. Acquisition data (days1-20) were followed by 6 days in which saline was substituted for nicotine (days 21-26) and then three days in which nicotine was replaced (days 27-29). Results are mean + SEM of data obtained from 7-9 animals per group (From Donny et al. 2003. Copyright © 2003 by Springer-Verlag. Reprinted with permission)