Introduction -- What are emotions? -- The emotional and the cognitive system -- Components and hierarchical organization of emotions -- Brain structures playing a critical role in different components and hierarchical levels of emotions -- Brain structures underlying the main components of emotions -- Brain structures involved in the highest levels of emotions and in the control of socially unacceptable emotional responses -- The history of research on emotional laterality -- The pioneers -- First interpretations of the different emotional behaviour shown by right and left brain-damaged patients -- Experimental and clinical investigations which have studied the non verbal communicative aspects of emotions -- Experimental and clinical investigations which have studied the autonomic components of emotions -- Possible implications for psychiatry of different models of emotional lateralization -- Recent trends in the study of the links between emotions and brain laterality -- Negative data obtained by functional neuroimaging studies of the neural correlates of emotions -- Laterality effects in brain structures playing a different role in emotional functions -- Emotional and behavioural disorders of patients with asymmetrical forms of Fronto-Temporal Degeneration -- General neurobiological models advanced to explain results obtained following these new lines of research -- A model based on the assumption of a primitive functional organization of the non-verbal right hemisphere -- A model assuming that different homeostatic models of awareness may originate from asymmetries in the peripheral autonomic nervous system -- Relationships between the lateralization of autonomic and of emotional activities -- Some psychopathological implications of hemispheric asymmetries for emotions -- The hypothesis assuming that major post-stroke depression and secondary mania may be caused respectively by left and right hemispheric lesions -- Psychopathological conditions in which a prominent role of the right hemisphere has been hypothesized -- Concluding remarks: Special relations between emotional system and sympathetic activities.