One of the characteristics of depression is a tendency to perceive sensory stimuli and everyday situations in an excessively negative way. But the mechanisms underpinning this "negativity bias," which can fuel the development of depressive symptoms, had previously remained largely unknown. To shed light on the question, scientists from the Institut Pasteur and the CNRS, in collaboration with psychiatrists from Paris Psychiatry and Neurosciences GHU, Inserm and the CEA, decided to explore the amygdala and observe how it functions during depressive episodes.