We are able to know what other people think by using (1) a sharing mechanism through which we access our repertoire of mental representations (e.g., intentions, feelings, sensory experiences) to explore both our own mental life and that of others, and (2) a self-other distinction (SOD) mechanism to distinguish representations pertaining to our own mental life from those of others ("she is sad, I am not"). How SOD works is poorly understood but one promising line of investigations is its links with Self-knowledge (SK), which refers to the collection of representations describing ourselves (e.g., personal memories, self-describing traits, life goals) and the processes allowing to form and access these representations. This project will be the first systematic empirical investigation of the interdependence between SOD and SK. The first work package will investigate how self-awareness, a key facet of SK, causally affects SOD performance by experimentally manipulating individuals’ level of self-awareness. The second work package will test 10 specific hypothesized links between facets of SK and SOD performance by assessing correlations in two large samples of healthy adults. The third work package will identify then neuromodulate the brain networks underpinning SK and SOD to examine their causal interdependence. In its full scope, this interdisciplinary project will support the elaboration of an integrated theoretical framework for the relation between SOD and SK.