title: Dopamine D₁ receptors and nonlinear probability weighting in risky choice.
abstract: Misestimating risk could lead to disadvantaged choices such as initiation of drug use (or gambling) and transition to regular drug use (or gambling). Although the normative theory in decision-making under risks assumes that people typically take the probability-weighted expectation over possible utilities, experimental studies of choices among risks suggest that outcome probabilities are transformed nonlinearly into subjective decision weights by a nonlinear weighting function that overweights low probabilities and underweights high probabilities. Recent studies have revealed the neurocognitive mechanism of decision-making under risk. However, the role of modulatory neurotransmission in this process remains unclear. Using positron emission tomography, we directly investigated whether dopamine D₁ and D₂ receptors in the brain are associated with transformation of probabilities into decision weights in healthy volunteers. The binding of striatal D₁ receptors is negatively correlated with the degree of nonlinearity of weighting function. Individuals with lower striatal D₁ receptor density showed more pronounced overestimation of low probabilities and underestimation of high probabilities. This finding should contribute to a better understanding of the molecular mechanism of risky choice, and extreme or impaired decision-making observed in drug and gambling addiction.
authors.affiliation: Department of Psychiatry, Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan. hidehiko@kuhp.kyoto-u.ac.jp
authors.forename: Hidehiko
authors.initials: H
authors.lastname: Takahashi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Matsui
authors.forename: Colin
authors.initials: C
authors.lastname: Camerer
authors.forename: Harumasa
authors.initials: H
authors.lastname: Takano
authors.forename: Fumitoshi
authors.initials: F
authors.lastname: Kodaka
authors.forename: Takashi
authors.initials: T
authors.lastname: Ideno
authors.forename: Shigetaka
authors.initials: S
authors.lastname: Okubo
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Takemura
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Arakawa
authors.forename: Yoko
authors.initials: Y
authors.lastname: Eguchi
authors.forename: Toshiya
authors.initials: T
authors.lastname: Murai
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Okubo
authors.forename: Motoichiro
authors.initials: M
authors.lastname: Kato
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ito
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Suhara
mesh_terms: D000328:Adult; D001931:Brain Mapping / Q000379:methods; D002247:Carbon Isotopes / Q000493:pharmacokinetics; D002755:Choice Behavior / Q000502:physiology*; D018492:Dopamine Antagonists / Q000493:pharmacokinetics; D006801:Humans; D008297:Male; D017711:Nonlinear Dynamics; D049268:Positron-Emission Tomography; D011336:Probability; D017447:Receptors, Dopamine D1 / Q000378:metabolism; D017448:Receptors, Dopamine D2 / Q000378:metabolism*; D012309:Risk-Taking; D013223:Statistics as Topic; D055815:Young Adult
chemical_list: D002247:Carbon Isotopes; D018492:Dopamine Antagonists; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2