We also tested effects of time on the slope paralleling our analysis of the IP -we split the dataset into thirds, coinciding with the design for the test of transitivity ( Finally, we looked at whether the slope was affected by inactivation just at the beginning of the session. As explained for the IP analysis, we narrowed our **data** to the first 4 trials of each offer (on average the first 29.9% of each session) and reran the two-way ANOVA test on this early session behavior. The critical interaction effect of Laser*Fiber was not significant. The main effect of Laser was significant. Further analysis revealed a significant difference in the simple effects between the laser-on and -off trials in the blocked fiber condition, but not in the patent fiber condition (see Supplementary file 2 for ANOVA results).