title: Dopaminergic modulation of distracter-resistance and prefrontal delay period signal.
abstract: Dopamine has long been implicated in the online maintenance of information across short delays. Specifically, dopamine has been proposed to modulate the strength of working memory representations in the face of intervening distracters. This hypothesis has not been tested in humans. We fill this gap using pharmacological neuroimaging. Healthy young subjects were scanned after intake of the dopamine receptor agonist bromocriptine or placebo (in a within-subject, counterbalanced, and double-blind design). During scanning, subjects performed a delayed match-to-sample task with face stimuli. A face or scene distracter was presented during the delay period (between the cue and the probe). Bromocriptine altered distracter-resistance, such that it impaired performance after face relative to scene distraction. Individual differences in the drug effect on distracter-resistance correlated negatively with drug effects on delay period signal in the prefrontal cortex, as well as on functional connectivity between the prefrontal cortex and the fusiform face area. These results provide evidence for the hypothesis that dopaminergic modulation of the prefrontal cortex alters resistance of working memory representations to distraction. Moreover, we show that the effects of dopamine on the distracter-resistance of these representations are accompanied by modulation of the functional strength of connections between the prefrontal cortex and stimulus-specific posterior cortex.
authors.affiliation: Radboud University Nijmegen, Donders Institute for Brain, Cognition and Behaviour, Centre for Cognitive Neuroimaging, P.O. Box 9101, 6500, HB, Nijmegen, The Netherlands, mirjambloemendaal@gmail.com.
authors.forename: Mirjam
authors.initials: M
authors.lastname: Bloemendaal
authors.forename: Martine R
authors.initials: MR
authors.lastname: van Schouwenburg
authors.forename: Asako
authors.initials: A
authors.lastname: Miyakawa
authors.forename: Esther
authors.initials: E
authors.lastname: Aarts
authors.forename: Mark
authors.initials: M
authors.lastname: D'Esposito
authors.forename: Roshan
authors.initials: R
authors.lastname: Cools
mesh_terms: D000293:Adolescent; D001288:Attention / Q000187:drug effects*; D001971:Bromocriptine / Q000494:pharmacology*; D003463:Cues; D004298:Dopamine / Q000502:physiology*; D018491:Dopamine Agonists / Q000494:pharmacology*; D004311:Double-Blind Method; D005145:Face; D005260:Female; D006801:Humans; D007206:Individuality; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008570:Memory, Short-Term / Q000187:drug effects*; D017397:Prefrontal Cortex / Q000187:drug effects*; D011930:Reaction Time / Q000187:drug effects; D055815:Young Adult
chemical_list: D018491:Dopamine Agonists; D001971:Bromocriptine; D004298:Dopamine