title: Dopamine asymmetries predict orienting bias in healthy individuals.
abstract: Pseudoneglect is traditionally viewed as reflecting right hemisphere specialization for processing spatial information, resulting in orienting toward the contralateral, left, hemispace. Recent evidence suggests that healthy individuals differ from each other in both direction and magnitude of orienting bias, and moreover, the bias displayed by a person is consistent across time, suggesting that it may represent a trait of the individual. Animal studies reveal consistent orienting bias within an individual, which reflects asymmetry in dopaminergic brain systems. We measured basal D2-like receptor binding using positron emission tomography and the high-affinity ligand [F-18]fallypride, to test the hypothesis that asymmetry in dopaminergic neurotransmission in healthy humans modulates the orienting bias in humans. As predicted, we found that individual differences in the direction and magnitude of the orienting bias were strongly associated with the pattern of asymmetric binding of dopamine (DA) D2 receptors in the striatum, as well as clusters in the frontal and temporal cortex. These findings show for the first time that orienting bias reflects individual differences in the lateralization of DA systems in the healthy human brain.
authors.affiliation: Department of Psychology, University of Haifa, Haifa 31905, Israel.
authors.forename: Rachel
authors.initials: R
authors.lastname: Tomer
authors.forename: Heleen A
authors.initials: HA
authors.lastname: Slagter
authors.forename: Bradley T
authors.initials: BT
authors.lastname: Christian
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Fox
authors.forename: Carlye R
authors.initials: CR
authors.lastname: King
authors.forename: Dhanabalan
authors.initials: D
authors.lastname: Murali
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Davidson
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology*; D001549:Benzamides / Q000032:analysis; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism*; D003342:Corpus Striatum / Q000000981:diagnostic imaging / Q000378:metabolism; D004192:Discrimination, Psychological; D005260:Female; D005462:Fluorine Radioisotopes; D006801:Humans; D008297:Male; D010775:Photic Stimulation; D049268:Positron-Emission Tomography; D011759:Pyrrolidines / Q000032:analysis; D017448:Receptors, Dopamine D2 / Q000378:metabolism*; D055815:Young Adult
chemical_list: D001549:Benzamides; D005462:Fluorine Radioisotopes; C094948:N-((1-allyl-2-pyrrolidinyl)methyl)-5-(3-fluoropropyl)-2,3-dimethoxybenzamide; D011759:Pyrrolidines; D017448:Receptors, Dopamine D2