A large body of evidence points to impairment in the decoding of emotional stimuli in Parkinson's disease (PD). These changes seem to be related to dysfunction of the mesocorticolimbic projections leading to dysfunction of the limbic cortico-subcortical loop that, throughout the basal ganglia, projects to limbic cortical regions such as the anterior cingulate cortex and the orbitofrontal cortex, which are known to be involved in emotional processing. Thus, presumably the occurrence of non-motor psychic symptoms and fluctuations in PD would also rely on the degeneration of this circuitry. Dopamine modulation of emotions has been frequently reported both in healthy subjects or PD patients, but the effect of subthalamic nucleus deep brain stimulation (STN-DBS) over mood symptoms is more controversial and there is still a paucity of data demonstrating its role in emotional processing. The objective of our study is to assess and compare the behavioral and electrophysiological effects of both dopamine and STN-DBS in PD during emotional processing. To do so, the Emotional Stroop task, a version of the classical Stroop test developed to investigate inhibition of emotional interference, will be performed by STN-DBS PD patients in four different treatment conditions while high resolution electroencephalographic cortical mapping is conducted. Using this approach, the investigators expect to better separate the mechanisms of psychic features related to either disease, dopaminergic treatment, subthalamic stimulation or the association of both, with the final aim of optimizing the clinical management of PD.