What do we know about the factors that influence our decisions? Are we aware of the true reasons of our ‘free’ choices? The ability to introspect and evaluate the origin of our actions constitutes a key metacognitive function but little is known of the cognitive process that underlie our sense of freedom of choice. In this talk I will present new studies investigating participants’ ability to make free decisions and introspect how much their decisions are indeed influenced, evaluating their true freedom of choice. In a series of behavioural and neuroimaging experiments, we have explored how participant endogenously select between alternative actions trying to detach their choice from perceptual information. Importantly we asked participants to evaluate their subjective freedom of choice after each decision, and compared these ratings to how much they were actually influenced by sensory input on each trial. Our results revealed three novel findings. First, sensory input biased “free” selection between alternative actions even when participants are trying to detach from it. Second participants remained unaware of that influence. Third, participants mistook opposing incoming perceptual information for being more free.