1 Sexual Dimorphism in the Human Brain: Evidence from Neuroimaging Julia Sacher ,1, 2 , Jane Neumann 1,3 , Hadas Okon-Singer 1 , Sarah Gotowiec 1 , Arno Villringer 1, 2 . 1 Max-Planck-Institute for Human Cognitive and Brain Sciences, Stephanstr. 1A, Leipzig, Germany. 2 Clinic of Cognitive Neurology, University of Leipzig, Liebigstr. 16, Leipzig, Germany. 3 Leipzig University Medical Center, IFB AdiposityDiseases, Leipzig, Germany. Abstract In recent years more and more emphasis has been placed on the investigation of sex differences in the human brain. Non-invasive neuroimaging techniques represent an essential tool in the effort to better understand the effects of sex on both brain structure and function. In this review we provide a comprehensive summary of the findings that were collected in human neuroimaging studies in vivo thus far: we explore sexual dimorphism in the human brain at the level of (1) brain structure, both in grey and white matter, observed by voxel-based morphometry (VBM) and diffusion tensor imaging (DTI), respectively; (2) baseline neural activity, studied using resting state functional magnetic resonance imaging (rs-fMRI) and positron emission tomography (PET); (3) neurochemistry, visualized by means of neuroreceptor ligand PET; and (4) task-related neural activation, investigated using functional magnetic resonance imaging (fMRI). Functional MRI findings from the literature are complemented by our own meta-analysis of fMRI studies on sex-specific differences in human emotional processing. Specifically, we used activation likelihood estimation (ALE) to provide a quantitative approach to mapping the consistency of neural networks involved in emotional