Figure 8.

Although the 7 s cue period described above captured periods of sign- and goal-tracking, there was some variation in behavior from trial to trial. Therefore, we isolated the portion of each trial in which rats were actively engaged with the lever or magazine. A, Example ratings of lever and magazine interaction intervals for individual trials. B, STs had significantly more cells that were responsive during their interaction with the lever CS than INs during interactions with either the lever CS or the food magazine and than GTs during interactions with the food magazine; ***p < 0.001. This was true for excitatory and inhibitory responses, as STs had more of both than INs and GTs; # p < 0.05–0.001. C, The increase in firing during interaction intervals (among excitatory cells only) was significantly greater in STs than GTs and IN-Lever; *p < 0.05, ***p < 0.001. There were significant correlations between probability difference scores and the percentage of responsive cells (D) and the firing rate change for individual rats (E).