Figure 6.3.
(a) Responses on the active lever, inactive lever and number of stimulus presentations (mean + SEM) during a 30-minute test for conditioned reinforcement by rats trained previously with a stimulus that was paired with sucrose (n=41), or the same stimulus that was explicitly unpaired with sucrose (n=25). (b) Interaction between stimulus-training condition (sucrose-paired vs. sucrose-unpaired) and drug contingency (contingent NIC vs. non-contingent NIC). Data from non-contingent SAL + stimulus conditions are also shown for comparison. Panels represent data from either the entire 180 minute test session (no break point), or after a 30 minute or 60 minute break point was imposed. Data are mean (* SEM) stimulus presentations earned on the last 2 days of the progressive ratio schedule. All interactions are significant at P<0.05 (From Chaudhri et al. 2006a. Copyright © 2006 by Springer-Verlag. Reprinted with permission)