Figure 7.

Testosterone influences discounting behavior of male rats. (A) Operant task for discounting behavior. Rats choose between two levers. The small reward lever delivers 1 pellet with minimal cost. The large reward lever delivers four pellets with increasing cost throughout the session. (B) For effort discounting behavior, the response requirement (number of lever presses) increases. (C) For probability discounting, the large reward is delivered with decreasing probability. Compared with vehicle controls (open circles), testosterone (closed circles) increases preference for the large reward lever in effort discounting, but reduces preference for the large reward lever in probability discounting. Adapted with permission from Ref. (190). Values presented as mean ± SEM. *p ≤ 0.05.