title: Processing of emotional information in the human subthalamic nucleus.
abstract: BACKGROUND
  The subthalamic nucleus (STN) is an efficient target for treating patients with Parkinson's disease as well as patients with obsessive-compulsive disorder (OCD) using high frequency stimulation (HFS). In both Parkinson's disease and OCD patients, STN-HFS can trigger abnormal behaviours, such as hypomania and impulsivity.
  
  
  METHODS
  To investigate if this structure processes emotional information, and whether it depends on motor demands, we recorded subthalamic local field potentials in 16 patients with Parkinson's disease using deep brain stimulation electrodes. Recordings were made with and without dopaminergic treatment while patients performed an emotional categorisation paradigm in which the response varied according to stimulus valence (pleasant, unpleasant and neutral) and to the instruction given (motor, non-motor and passive).
  
  
  RESULTS
  Pleasant, unpleasant and neutral stimuli evoked an event related potential (ERP). Without dopamine medication, ERP amplitudes were significantly larger for unpleasant compared with neutral pictures, whatever the response triggered by the stimuli; and the magnitude of this effect was maximal in the ventral part of the STN. No significant difference in ERP amplitude was observed for pleasant pictures. With dopamine medication, ERP amplitudes were significantly increased for pleasant compared with neutral pictures whatever the response triggered by the stimuli, while ERP amplitudes to unpleasant pictures were not modified.
  
  
  CONCLUSIONS
  These results demonstrate that the ventral part of the STN processes the emotional valence of stimuli independently of the motor context and that dopamine enhances processing of pleasant information. These findings confirm the specific involvement of the STN in emotional processes in human, which may underlie the behavioural changes observed in patients with deep brain stimulation.
authors.affiliation: Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière (CRICM), Université Pierre et Marie Curie-Paris 6, Paris, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Buot
authors.forename: Marie-Laure
authors.initials: ML
authors.lastname: Welter
authors.forename: Carine
authors.initials: C
authors.lastname: Karachi
authors.forename: Jean-Baptiste
authors.initials: JB
authors.lastname: Pochon
authors.forename: Eric
authors.initials: E
authors.lastname: Bardinet
authors.forename: Jérôme
authors.initials: J
authors.lastname: Yelnik
authors.forename: Luc
authors.initials: L
authors.lastname: Mallet
mesh_terms: D001921:Brain / Q000187:drug effects / Q000502:physiology*; D046690:Deep Brain Stimulation / Q000523:psychology; D018491:Dopamine Agonists / Q000494:pharmacology / Q000627:therapeutic use; D004644:Emotions / Q000187:drug effects / Q000502:physiology*; D005071:Evoked Potentials / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D010300:Parkinson Disease / Q000188:drug therapy / Q000503:physiopathology*; D010775:Photic Stimulation; D011597:Psychomotor Performance / Q000187:drug effects / Q000502:physiology*; D020531:Subthalamic Nucleus / Q000187:drug effects / Q000502:physiology* / Q000503:physiopathology*
chemical_list: D018491:Dopamine Agonists
keywords: Behavioural Disorder; Cognitive Electrophysiology; Evoked Potentials; Parkinson's Disease; Psychology, Experimental