title: Extrastriatal dopamine D2 receptor binding modulates intraindividual variability in episodic recognition and executive functioning.
abstract: Intraindividual variability (IIV) reflects lawful but transient within-person changes in performance. Increased IIV in cognition shares systematic associations with numerous conditions characterized by alterations in dopamine (DA) neuromodulation (e.g., old age, ADHD, schizophrenia, and Parkinson's disease). In a group of normal middle-aged adults, we examined links between PET-derived measures of D2 receptor binding in striatum, orbitofrontal cortex (OFC), anterior cingulate cortex (ACC), and hippocampus (HC) and IIV for tasks assessing recognition memory and executive functioning. An index of IIV, the intraindividual standard deviation (ISD), was computed across successful response latency trials for each cognitive outcome. Lower D2 binding in OC, ACC, and HC, but not striatum, was associated with increasing ISDs for the memory and executive measures. Consistent with neurocomputational models, the present findings suggest a role for extrastriatal DA neurotransmission in modulating variability in cognitive functioning.
authors.affiliation: Department of Psychology, University of Victoria, Victoria, British Columbia, Canada.
authors.forename: Stuart W S
authors.initials: SW
authors.lastname: MacDonald
authors.forename: Simon
authors.initials: S
authors.lastname: Cervenka
authors.forename: Lars
authors.initials: L
authors.lastname: Farde
authors.forename: Lars
authors.initials: L
authors.lastname: Nyberg
authors.forename: Lars
authors.initials: L
authors.lastname: Bäckman
mesh_terms: D000328:Adult; D000368:Aged; D002247:Carbon Isotopes / Q000378:metabolism; D003342:Corpus Striatum / Q000000981:diagnostic imaging / Q000378:metabolism*; D005260:Female; D006801:Humans; D007206:Individuality; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D049268:Positron-Emission Tomography / Q000379:methods; D011340:Problem Solving / Q000502:physiology*; D011485:Protein Binding; D020891:Raclopride / Q000378:metabolism; D011869:Radioligand Assay; D011930:Reaction Time; D017448:Receptors, Dopamine D2 / Q000378:metabolism*; D021641:Recognition, Psychology / Q000502:physiology*
chemical_list: D002247:Carbon Isotopes; D017448:Receptors, Dopamine D2; D020891:Raclopride