title: Eating to stop: tyrosine supplementation enhances inhibitory control but not response execution.
abstract: Animal studies and research in humans have shown that the supplementation of tyrosine, or tyrosine-containing diets, increase the plasma tyrosine and enhance brain dopamine (DA). However, the strategy of administering tyrosine (and the role of DA therein) to enhance cognition is unclear and heavily debated. We studied, in a healthy population, whether tyrosine supplementation improves stopping overt responses, a core cognitive-control function. In a double-blind, placebo-controlled, within-subject design, one hour following the administration of tyrosine (corresponding to the beginning of the 1h-peak of the plasma concentration) or placebo, participants performed a stop-signal task-which taps into response inhibition and response execution speed. Participants in the Tyrosine condition were more efficient in inhibiting unwanted action tendencies but not in reacting to go signals. This is the first demonstration that the supplementation of tyrosine selectively targets, and reliably improves the ability to stop overt responses.
authors.affiliation: Leiden University, Cognitive Psychology Unit & Leiden Institute for Brain and Cognition, Leiden, The Netherlands. Electronic address: colzato@fsw.leidenuniv.nl.
authors.forename: Lorenza S
authors.initials: LS
authors.lastname: Colzato
authors.affiliation: Leiden University, Cognitive Psychology Unit & Leiden Institute for Brain and Cognition, Leiden, The Netherlands.
authors.forename: Bryant J
authors.initials: BJ
authors.lastname: Jongkees
authors.affiliation: Leiden University, Cognitive Psychology Unit & Leiden Institute for Brain and Cognition, Leiden, The Netherlands.
authors.forename: Roberta
authors.initials: R
authors.lastname: Sellaro
authors.affiliation: University of Amsterdam, Amsterdam Center for the Study of Adaptive Control in Brain and Behaviour (Acacia), Psychology Department, Amsterdam, The Netherlands.
authors.forename: Wery P M
authors.initials: WP
authors.lastname: van den Wildenberg
authors.affiliation: Leiden University, Cognitive Psychology Unit & Leiden Institute for Brain and Cognition, Leiden, The Netherlands.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Hommel
mesh_terms: D000284:Administration, Oral; D000704:Analysis of Variance; D001794:Blood Pressure / Q000187:drug effects; D018592:Cross-Over Studies; D019587:Dietary Supplements; D004311:Double-Blind Method; D056344:Executive Function / Q000187:drug effects*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007266:Inhibition, Psychological; D009483:Neuropsychological Tests; D010775:Photic Stimulation; D011930:Reaction Time / Q000187:drug effects; D014443:Tyrosine / Q000008:administration & dosage*; D055815:Young Adult
chemical_list: D014443:Tyrosine
keywords: Dopamine; Inhibitory control; Stop-signal task; Tyrosine