title: HPA axis function predicts development of working memory in boys with FXS.
abstract: The present study examines verbal working memory over time in boys with fragile X syndrome (FXS) compared to nonverbal mental-age (NVMA) matched, typically developing (TD) boys. Concomitantly, the relationship between cortisol-a physiological marker for stress-and verbal working memory performance over time is examined to understand the role of physiological mechanisms in cognitive development in FXS. Participants were assessed between one and three times over a 2-year time frame using two verbal working memory tests that differ in complexity: memory for words and auditory working memory with salivary cortisol collected at the beginning and end of each assessment. Multilevel modeling results indicate specific deficits over time on the memory for words task in boys with FXS compared to TD controls that is exacerbated by elevated baseline cortisol. Similar increasing rates of growth over time were observed for boys with FXS and TD controls on the more complex auditory working memory task, but only boys with FXS displayed an association of increased baseline cortisol and lower performance. This study highlights the benefit of investigations of how dynamic biological and cognitive factors interact and influence cognitive development over time.
authors.affiliation: Department of Psychology, 1512 Pendleton Street, University of South Carolina, Columbia, SC 29208, USA.
authors.forename: Jessica F
authors.initials: JF
authors.lastname: Scherr
authors.affiliation: Department of Psychology, 1512 Pendleton Street, University of South Carolina, Columbia, SC 29208, USA.
authors.forename: Laura J
authors.initials: LJ
authors.lastname: Hahn
authors.affiliation: Department of Allied Health Sciences, 1028 Bondurant Hall, University of North Carolina School of Medicine, Chapel Hill, NC 27599-4120, USA; Department of Psychiatry, 1028 Bondurant Hall, University of North Carolina School of Medicine, Chapel Hill, NC 27599-4120, USA.
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Hooper
authors.affiliation: Department of Special Education, Box 228 Peabody College, Vanderbilt University, Nashville, TN 37203, USA.
authors.forename: Deborah
authors.initials: D
authors.lastname: Hatton
authors.affiliation: Department of Psychology, 1512 Pendleton Street, University of South Carolina, Columbia, SC 29208, USA. Electronic address: jane.roberts@sc.edu.
authors.forename: Jane E
authors.initials: JE
authors.lastname: Roberts
mesh_terms: D000293:Adolescent; D002648:Child; D002657:Child Development / Q000502:physiology; D003071:Cognition / Q000502:physiology*; D032882:Comprehension / Q000502:physiology; D005600:Fragile X Syndrome / Q000503:physiopathology / Q000523:psychology*; D006801:Humans; D007030:Hypothalamo-Hypophyseal System / Q000503:physiopathology*; D007360:Intelligence / Q000502:physiology; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D009483:Neuropsychological Tests; D010913:Pituitary-Adrenal System / Q000503:physiopathology*
keywords: Cortisol; Fragile X syndrome; Longitudinal; Verbal working memory