Working memory (WM) plays a central role in many cognitive functions, such as decision-making and planning. This thesis aims to deepen our understanding of its neural bases by combining lesion analysis and functional connectivity approaches in both healthy individuals and patients with brain injuries. Three complementary studies are presented. The first study demonstrates that focal lesions in the right hemisphere (RH) significantly impair WM, regardless of modality (verbal or visuospatial), involving a distributed network that includes frontal, parietal, and temporal regions, as well as associated white matter tracts. The second study reveals that a stroke affecting the RH leads to a reduction in intra-hemispheric connectivity and a simultaneous increase in inter-hemispheric connectivity, suggesting the existence of adaptive mechanisms for functional reorganization. Finally, the third study, conducted in healthy participants, shows that WM relies on the integrity of fronto-parietal and sensorimotor networks, which are engaged in executive functions such as the active manipulation of information. Together, these studies contribute to refining our understanding of the brain substrates of working memory and open promising avenues for neuropsychological assessment and rehabilitation.