Decision-making can be defined as cognitive process based on the selection of a goal-directed action from a set of choices. In perceptual decision-making, this behavior guiding choice relies on sensory information. The associative part of the striatum has been proposed to be essential for such decision-making processes, in particular to select the appropriate action plan according to the sensory evidence. Parvalbumin interneurons (PVI) in the associative striatum may have a crucial role in this action plan selection despite their low numbers. Indeed, by inhibiting striatal processing, PVI may allow to gain time to accumulate more sensory information and optimize choice, especially during difficult decision.In this project, we have shown that in a visual-guided bilateral choice task in mice, PV interneurons in the central medial striatum are steadily recruited during the entire duration of the decision. These results suggest that PVI have a crucial role to play in holding the action until the decision is made, allowing to integrate more visual information if needed. To test this hypothesis, we developed an optogenetics approach, allowing inhibition of PV interneurons during decision-making. The preliminary results suggest that such PVI inhibition provokes a shortening of the decision-making process with decreased performance, in line with our conceptual framework.