Effects of dopaminergic modulation on electrophysiological brain response to affective stimuli.
BACKGROUND
Several theoretical accounts of the role of dopamine suggest that dopamine has an influence on the processing of affective stimuli. There is some indirect evidence for this from studies showing an association between the treatment with dopaminergic agents and self-reported affect.


METHODS
We addressed this issue directly by examining the electrophysiological correlates of affective picture processing during a single-dose treatment with a dopamine D2 agonist (bromocriptine), a dopamine D2 antagonist (haloperidol), and a placebo. We compared early and late event-related brain potentials (ERPs) that have been associated with affective processing in the three medication treatment conditions in a randomized double-blind crossover design amongst healthy males. In each treatment condition, subjects attentively watched neutral, pleasant, and unpleasant pictures while ERPs were recorded.


RESULTS
Results indicate that neither bromocriptine nor haloperidol has a selective effect on electrophysiological indices of affective processing. In concordance with this, no effects of dopaminergic modulation on self-reported positive or negative affect was observed. In contrast, bromocriptine decreased overall processing of all stimulus categories regardless of their affective content.


CONCLUSIONS
The results indicate that dopaminergic D2 receptors do not seem to play a crucial role in the selective processing of affective visual stimuli.
Franken
Ingmar H A
IH
Erasmus Affective Neuroscience Lab, Institute of Psychology, Erasmus University Rotterdam, Rotterdam, The Netherlands. franken@fsw.eur.nl
Nijs
Ilse
I
Pepplinkhuizen
Lolke
L
D000293:Adolescent; D000328:Adult; D000339:Affect / Q000187:drug effects* / Q000502:physiology; D001143:Arousal / Q000187:drug effects* / Q000502:physiology; D001288:Attention / Q000187:drug effects / Q000502:physiology; D001931:Brain Mapping; D001971:Bromocriptine / Q000494:pharmacology*; D002540:Cerebral Cortex / Q000187:drug effects* / Q000503:physiopathology; D018592:Cross-Over Studies; D004298:Dopamine / Q000378:metabolism*; D018491:Dopamine Agonists / Q000494:pharmacology*; D018492:Dopamine Antagonists / Q000494:pharmacology*; D004311:Double-Blind Method; D004569:Electroencephalography / Q000187:drug effects*; D005074:Evoked Potentials, Visual / Q000187:drug effects / Q000502:physiology; D005149:Facial Expression; D006220:Haloperidol / Q000494:pharmacology*; D006801:Humans; D008297:Male; D009042:Motivation; D010364:Pattern Recognition, Visual / Q000187:drug effects* / Q000502:physiology; D017448:Receptors, Dopamine D2 / Q000187:drug effects / Q000502:physiology; D012815:Signal Processing, Computer-Assisted
D018491:Dopamine Agonists; D018492:Dopamine Antagonists; D017448:Receptors, Dopamine D2; D001971:Bromocriptine; D006220:Haloperidol; D004298:Dopamine