behavioral protocol. Letters (vowel and consonant; upper- or lower- case) are presented in several colours into successive blocks. Each block included a series of eight letters. Each colour required a specific task given by a fixed rule (contextual control) but for some colour, the rule changes sometimes (episodic control). Participants are informed that payoffs vary according to their own performance. A frame indicates essay with bonus reward. Moreover a dashed frame indicates a low-bonus reward and a solid frame means a high-bonus reward. Thus different blocks are designed: low-incentive block and high incentive block.