Accurate execution of our directed behaviors in the immediate environment allows the vast majority of our daily activities. Through the movements of our eyes and different parts of our body, we perceive, explore and act on our environment and can exchange and communicate with others. The mechanisms of sensorimotor adaptation of saccades (saccadic adaptation) contribute on the one hand to maintain the accuracy of saccades in the short, medium and long term, by opposing the deleterious effects of various physiological changes (development, aging), pathological or environmental (optical corrections).

The aim of this study is to identify neuronal structures and networks involved in saccadic adaptation through the study of brain metabolic activation (BOLD) during the development of the adaptation of reactive saccades. The study will be organized in a single session with 3 runs. Each run include 4 blocks: 3 include the double-step target paradigm RND, U+, U-) and one without target jump (STA). The 'U+'/ 'U-'blocks include saccadic trials with forward/backward displacement of the target during a targeting saccade, the 'RND' block include saccadic trials with random target jump (forward or backward) and the 'STA' block are trials without displacement of the target. Each subject will make 12 repetitions of the 4 blocks.

Inclusion Criteria:

- Age: 18 to 40 years included,

Exclusion Criteria:

• Known ophthalmological or neurological pathology,
• Non-stabilized medical condition,
• Taking psychotropic treatment,
• No fluency in reading in French,
• Pregnant and / or breastfeeding woman