Table 1.

Design of Experiments 1 and 2

ConditioningInstrumental trainingTransfer test
S1–O1S1Embedded Image
S2–O2R1→O1; R2→O2S2R1 vs R2
  • During initial conditioning rats received pairing of three auditory cues, S1, S2, and S3 (noise, tone, and clicker, counterbalanced), with three separate outcomes, O1, O2, and O3 (pellet, sucrose, or polycose, counterbalanced). They then received instrumental training on two separate lever press actions, R1 and R2, each delivering one of the outcomes used in initial conditioning, O1 or O2. Finally a test was conducted on the levers in extinction in the presence of each of the three stimuli. The tests of S1 and S2 provide an assessment of the effects of the outcome-specific predictions of the cues. The test of S3, predicting an outcome not earned on the levers, provides a test of the general excitatory effects of reward prediction.