Stimulating a specific sub-region of the prefrontal cortex in mice or rats caused them to become winners regardless of prior win/loss history.

“And they did a simple experiment where the experimenters increased or decreased the activity of this brain area in the prefrontal cortex, little sub region of the prefrontal cortex. And what they found is if they stimulated this brain area, a mouse or rat, regardless of whether or not it had been a winner or loser before, became a winner every single time. And they showed that if they blocked the activity of this brain area, regardless of whether or not the mouse or rat had been a winner or loser, it became a loser every single time.”