title: Neurofeedback-mediated self-regulation of the dopaminergic midbrain.
abstract: The dopaminergic system is involved in reward encoding and reinforcement learning. Dopaminergic neurons from this system in the substantia nigra/ventral tegmental area complex (SN/VTA) fire in response to unexpected reinforcing cues. The goal of this study was to investigate whether individuals can gain voluntary control of SN/VTA activity, thereby potentially enhancing dopamine release to target brain regions. Neurofeedback and mental imagery were used to self-regulate the SN/VTA. Real-time functional magnetic resonance imaging (rtfMRI) provided abstract visual feedback of the SN/VTA activity while the subject imagined rewarding scenes. Skin conductance response (SCR) was recorded as a measure of emotional arousal. To examine the effect of neurofeedback, subjects were assigned to either receiving feedback directly proportional (n=15, veridical feedback) or inversely proportional (n=17, inverted feedback) to SN/VTA activity. Both groups of subjects were able to up-regulate SN/VTA activity initially without feedback. Veridical feedback improved the ability to up-regulate SN/VTA compared to baseline while inverted feedback did not. Additional dopaminergic regions were activated in both groups. The ability to self-regulate SN/VTA was differentially correlated with SCR depending on the group, suggesting an association between emotional arousal and neurofeedback performance. These findings indicate that SN/VTA can be voluntarily activated by imagery and voluntary activation is further enhanced by neurofeedback. The findings may lead the way towards a non-invasive strategy for endogenous control of dopamine.
authors.affiliation: Rehabilitation Engineering Laboratory, Department of Health Sciences and Technology, ETH Zurich, CH-8092, Switzerland.
authors.forename: James
authors.initials: J
authors.lastname: Sulzer
authors.forename: Ranganatha
authors.initials: R
authors.lastname: Sitaram
authors.forename: Maria Laura
authors.initials: ML
authors.lastname: Blefari
authors.forename: Spyros
authors.initials: S
authors.lastname: Kollias
authors.forename: Niels
authors.initials: N
authors.lastname: Birbaumer
authors.forename: Klaas Enno
authors.initials: KE
authors.lastname: Stephan
authors.forename: Andreas
authors.initials: A
authors.lastname: Luft
authors.forename: Roger
authors.initials: R
authors.lastname: Gassert
mesh_terms: D000328:Adult; D001931:Brain Mapping; D059290:Dopaminergic Neurons / Q000502:physiology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D019018:Imagery, Psychotherapy; D008279:Magnetic Resonance Imaging; D008297:Male; D008636:Mesencephalon / Q000502:physiology*; D058765:Neurofeedback / Q000502:physiology*; D012201:Reward; D055815:Young Adult
keywords: Dopamine; Neurofeedback; Real-time fMRI; Skin conductance response; Substantia nigra