"Distinguishing between conscious and unconscious processes is a fundamental issue for our understanding of the human mind. Most research on this topic has been limited to a static perspective, by studying static stimuli, by considering processing as a function of present information, and by focusing on a single, adult stage of development. Yet, both conscious and unconscious mental processes are intrinsically driven by dynamic properties. We will study these properties by relying on behavioral and brain imaging methods along three tracks:1) Unconscious perception: Our visual system is, in real life, constantly receiving unconscious sequences of information that will generate dynamic and constantly updated processing streams. We will study these dynamic unconscious streams, thanks to Gaze-Contingent Substitution, a novel approach allowing for the presentation of subliminal videos and sequences of stimuli.2) Conscious perception: Construction of a conscious percept does not only depend on present stimulation but also on interactions with prior knowledge. Relying on the Bayesian framework, we will study the mechanisms by which prior knowledge leads to the reconstruction of perceptual contents, by ""filling-in"" missing information during situations of partial awareness.3) The maturation of consciousness: Using both psychophysical measures of visibility thresholds and high-density EEG, we will study the neural distinction between conscious and unconscious processes in pre-verbal infants, and whether consciousness develops through the maturation of posterior brain regions encoding sensory information, or rather anterior prefrontal regions related to attention and executive control.The expected impact of the project will be 1) to evidence sequential and complex forms of subliminal influences 2) to specify the cognitive mechanisms leading to perceptual illusions 3) to provide new insights on the mystery of how consciousness develops in humans."