title: A functional investigation of RAN letters, digits, and objects: how similar are they?
abstract: Although rapid automatized naming (RAN) of letters, digits, and objects are popular tasks and have been used interchangeably to predict academic performance, it remains unknown if they tap into the same neural regions. Thus, the purpose of this study was to examine the neural overlap across different RAN tasks. Fifteen university students were assessed on RAN digits, letters, and objects using functional magnetic resonance imaging (fMRI). Results showed a common neural pattern that included regions related to motor planning (e.g., cerebellum), semantic access (middle temporal gyrus), articulation (supplementary motor association, motor/pre-motor, anterior cingulate cortex), and grapheme-phoneme mapping (ventral supramarginal gyrus). However, RAN digits and letters showed many unique regions of activation over and above RAN objects particularly in semantic and articulatory regions, including precuneus, bilateral supramarginal gyrus, nucleus accumbens and thalamus. The only region unique to RAN objects included bilateral fusiform, a region commonly implicated in object processing. Overall, our results provide the first neural evidence for a stronger relationship between RAN letters and digits than when either task is compared to RAN objects.
authors.affiliation: Department of Communication Sciences and Disorders, Faculty of Rehabilitation Medicine, University of Alberta, Canada; Centre for Neuroscience, University of Alberta, Canada. Electronic address: jacqueline.cummine@ualberta.ca.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Cummine
authors.affiliation: Centre for Neuroscience, University of Alberta, Canada.
authors.forename: Eszter
authors.initials: E
authors.lastname: Szepesvari
authors.affiliation: Department of Communication Sciences and Disorders, Faculty of Rehabilitation Medicine, University of Alberta, Canada.
authors.forename: Brea
authors.initials: B
authors.lastname: Chouinard
authors.affiliation: Centre for Neuroscience, University of Alberta, Canada.
authors.forename: Wahab
authors.initials: W
authors.lastname: Hanif
authors.affiliation: Department of Educational Psychology, University of Alberta, Canada.
authors.forename: George K
authors.initials: GK
authors.lastname: Georgiou
mesh_terms: D000293:Adolescent; D000328:Adult; D001332:Automatism; D001921:Brain / Q000098:blood supply / Q000502:physiology*; D001931:Brain Mapping; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008433:Mathematics; D009483:Neuropsychological Tests; D009716:Numerical Analysis, Computer-Assisted; D010100:Oxygen / Q000097:blood; D010364:Pattern Recognition, Visual / Q000502:physiology*; D011932:Reading; D018709:Statistics, Nonparametric; D055815:Young Adult
chemical_list: D010100:Oxygen
keywords: Alphanumeric RAN; Non-alphanumeric RAN; Rapid automatized naming