Reaction time results.

<p>Reaction time data for each stimulus discriminability, orientation, and session (reward, stimulus conditioned with reward; non-reward, stimulus conditioned with tasteless saliva; tr, average of conditioning sessions; 60%, low-contrast stimuli; 90%, high-contrast stimuli; 100%, maximal contrast stimuli used in conditioning session). Reaction times for stimuli conditioned with reward were significantly shorter than those with non-reward from the conditioning session to experimental session 3. In session 4, this pattern of reaction time difference disappeared. Error bars represent ±1 s.e.m.