Fig. 3.

Responses to the go cue and to the reward delivery. (A) In stimulus-present decisions the DA response at the go signal linearly decreased with the amplitude of the stimulus. (B) The dependence on the amplitude completely disappeared in DA activity at the reward delivery (R² = 0.58, P = 0.02 for the linear regression at the go cue; R² = 0.02, P = 0.72 for the linear regression at the reward delivery). For details about the standardized responses to the go cue and to the reward delivery see SI Materials and Methods.