title: Increased intraindividual reaction time variability in persons with neuropsychiatric manifestations of systemic lupus erythematosus.
abstract: Systemic Lupus Erythematosus (SLE) can affect multiple organ systems, including the central (CNS) and/or peripheral nervous system. Individuals with nervous system involvement (termed Neuropsychiatric SLE or NPSLE) can present with nonspecific symptoms such as cognitive dysfunction. It is difficult to ascertain whether this is a direct consequence of lupus disease activity on the brain. Intraindividual variability, measured through trial-to-trial reaction time variation, has been proposed as a behavioral marker of CNS integrity. We compared 14 NPSLE, 20 non-NPSLE, and 27 age-matched healthy participants using multiple variability metrics. Variability was increased in NPSLE compared with non-NPSLE participants, and was increased throughout the distribution rather than there being a selective increase in extreme reaction times. Variability metrics were strongly intercorrelated providing convergent evidence that the different metrics are tapping similar processes. The results suggest that there is ongoing disruption to cognitive processing in NPSLE and may indicate small fluctuations in attention.
authors.affiliation: Brighton and Sussex Medical School, The University of Sussex, Brighton BN1 9PX, UK School of Psychology, University of Leeds, Leeds LS2 9JT, UK r.i.haynes@leeds.ac.uk.
authors.forename: Becky I
authors.initials: BI
authors.lastname: Haynes
authors.affiliation: School of Psychology, University of Leeds, Leeds LS2 9JT, UK.
authors.forename: David
authors.initials: D
authors.lastname: Bunce
authors.affiliation: Brighton and Sussex Medical School, The University of Sussex, Brighton BN1 9PX, UK.
authors.forename: Kevin A
authors.initials: KA
authors.lastname: Davies
authors.affiliation: School of Psychology, University of Sussex, Falmer BN1 9QH, UK.
authors.forename: Jenifer M
authors.initials: JM
authors.lastname: Rusted
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007206:Individuality; D020945:Lupus Vasculitis, Central Nervous System / Q000523:psychology*; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011930:Reaction Time / Q000502:physiology*
keywords: Ex-Gaussian; Intraindividual variability; Neuropsychiatric Systemic Lupus Erythematosus (NPSLE); Reaction time variability