How does brain process favorable feedback with low possibility: An ERP research

Humans often learn from outcome feedback to modify the knowledge of objects/things, even to optimize subsequent strategies. Some studies have documented that participants divided outcomes into two sides in reward task: favorite and unfavorable outcome. But in real life we estimate outcome related closely at least two dimensions: whether the result will benefit us, and how frequent the result will occur. In this pilot ERP investigation, we adopt an elaborate gamble task to divide favorability evaluation and possibility evaluation, and assume FN and P300 are indices for favorability and possibility respectively. Results show that FN were significantly more negative in the loss condition than in the gain condition, and P300 were significantly more positive in the gain/low-possibility condition than in the loss/high-possibility condition.