We present an interdisciplinary project which aims to evaluate the neurobiological correlates of emotion processing in primary insomnia. The dimensional approach of emotions (e.g. Bradley, 2000) suggests that they can be described by referring to two dimensions: arousal and valence. In insomnia, while the role of arousal has been widely investigated, few studies have considered the valence. This study aims at evaluating both these dimensions, through a combination of psychological and neurobiological methods. Thirty people with primary insomnia (PI) and thirty good sleepers (GS) will watch neutral, negative and poor sleep-related pictures controlled for arousal and valence. During the task, brain activity will be recorded through functional magnetic resonance image (fMRI). Pictures will be presented within a blocked design. Cortisol levels will be measured to investigate differences between groups due to the quality of sleep. Increased cortisol release should be positively correlated with the severity of the symptoms of insomnia. With respect to the fMRI task, the PI should present an enhanced response to negative stimuli related and unrelated to sleep compared to GS. The innovative aspect of this project is the consideration of the valence dimension, and not only of the arousal dimension, when investigating the physiological correlates of emotions in people with insomnia. The aim is to investigate which neurobiological mechanisms intervene in the relation between the processing of the valence and of the arousal of the stimuli and the quality of sleep. This is expected to deepen the knowledge of insomnia and its relation with psychopathology. Results could have an impact on psychological treatment of insomnia, for example introducing strategies which aim at increasing the patient’s self-regulation of the emotional charge associated with sleep. Bradley (2000). In Cacioppo et al. (Eds.). Handbook of Psychophysiology, 2nd edition, Cambridge University Press.