Figure 9. Intra-amygdala infusion of lidocaine facilitates extinction of responding associated to the old duration.

The figure shows the distribution of the times at which rats started to suppress after the CS onset ((a), start times) and at which they resumed back to their baseline lever-pressing ((b), stop times) when the CS–US interval was shifted from 30 s (before shift) to 10 s (for 3 blocks of 4 sessions). Stop times appeared to reflect both learning of the new duration (stops between 10 and 30 s) and extinction of the oId one (stops >30 s, shaded area) in the saline group (n=10), whilst in the lidocaine group (n=9), extinction of responding to the old time was already optimal early on after the shift.