Responses of the same putative DA neuron in the NR environment of Pavlovian task with scene. In the NR environment, another scene was presented, and the other three conditioned stimuli were associated with air-puff with 100%, 50% and 0% probability, respectively. The environments were pseudo-randomly switched within the block. The trial started after the presentation of a scene image (diameter: 50 degrees) on the screen. After 1.08 s, a timing cue was presented on the scene. After 0.68 s, the timing cue disappeared, and one of the three conditioned stimuli was presented in each environment. After 1.5 s, the conditioned stimulus disappeared, and the unconditioned stimulus (water reward in PR or air-puff in NR) was delivered. Actual scenes and fractals for CSs used are shown on the left. The top row shows a raster plot of firing for the scene and each CS and US in the set, with dots indicating spike times. The bottom row shows the average firing rate in the set. The dotted line indicates the same level as the averaged baseline firing rates. ITI inter-trial interval, PR possible-reward, NR no-reward, CS conditioned stimulus; US, unconditioned stimulus, DA Dopamine.
