Figure 1.

Sucrose discrimination paradigm and behavioral performance. A, Schematic of task structure. The first lick delivered after trial initiation, signaled by white noise onset, resulted in a brief period of reinforcer availability. Subjects were required to withhold licking for 5 s to initiate a new trial. Bouts designate licking episodes during reinforcer delivery, and unreinforced bouts indicate licking episodes during which no reinforcer was delivered. B, Mean bout length increased monotonically with increasing sucrose concentration (p < 0.05 for all post hoc comparisons) for 0, 3, and 10% sucrose reinforcers. C, Mean intertrial interval increased with increasing sucrose concentration (p < 0.05 for all post hoc comparisons; data taken from 22 behavioral sessions in 14 rats for B and C).