Effects of motivational state and reward content on risk preference.

A. Experienced reward variance on the risky lever after water deprivation (average of last 3 sessions; probability of reward on the risky lever = 12.5%). Error bars indicate standard error of the means (SEM). Sucrose = 10% sucrose; alcohol = 10% sucrose and 20% ethanol. B. Risk preference after water deprivation. The sucrose group displayed higher risk aversion, whereas the alcohol group was risk neutral. C. Number of presses on the two levers (average of last 3 sessions). .D. Rate of lever pressing during the last session. E. Experienced reward variance on the risky lever after food deprivation (12.5%). F. Risk preference after food deprivation. The sucrose group displayed higher risk aversion, whereas the alcohol group was risk neutral. G. Total number of lever presses in a session (average of last 3 sessions). H. Rate of lever pressing during the last session (12.5%). I. Choice latency (the time it takes the animal to press the lever once the trial starts). After either food or water deprivation, sucrose group showed much shorter latency compared with the alcohol group (12.5%, average of last 3 sessions).