title: Neural substrates for forward and backward recitation of numbers and the alphabet: a close examination of the role of intraparietal sulcus and perisylvian areas.
abstract: Despite numerous studies on the neural basis of numerical processing, few studies have examined the neural substrates of one of the most basic numerical processing-number sequence recitation. The present study used fMRI to investigate neural substrates of number sequence recitation, focusing on the intraparietal sulcus (IPS) and perisylvian areas. This study used a 2 (number versus alphabet) x 2 (forward versus backward recitation) design. 12 Chinese undergraduates were asked to recite overtly but gently numerical and alphabetical sequences forward and backward. Results showed that, for both numerical and alphabetic sequences, the left IPS was activated when performing backward recitation, but not when performing forward recitation. In terms of perisylvian areas, all four tasks elicited activation in bilateral superior temporal gyrus and inferior frontal gyrus, but forward recitation elicited greater activation in the left posterior superior temporal gyrus than did backward recitation, whereas backward recitation elicited greater activation in the left inferior frontal gyrus than did forward recitation. These results suggest that forward recitation of numbers and the alphabet is typically based on verbal processing of numbers implemented in the perisylvian area, whereas backward recitation would likely require additional neural resources in the IPS.
authors.affiliation: State Key Lab of Cognitive Neuroscience and Learning, Beijing Normal University, China.
authors.forename: Xinlin
authors.initials: X
authors.lastname: Zhou
authors.forename: Chuansheng
authors.initials: C
authors.lastname: Chen
authors.forename: Hongchuan
authors.initials: H
authors.lastname: Zhang
authors.forename: Gui
authors.initials: G
authors.lastname: Xue
authors.forename: Qi
authors.initials: Q
authors.lastname: Dong
authors.forename: Zhen
authors.initials: Z
authors.lastname: Jin
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.forename: Chunyan
authors.initials: C
authors.lastname: Peng
authors.forename: Hui
authors.initials: H
authors.lastname: Zhao
authors.forename: Yi
authors.initials: Y
authors.lastname: Guo
authors.forename: Ting
authors.initials: T
authors.lastname: Jiang
authors.forename: Chunhui
authors.initials: C
authors.lastname: Chen
mesh_terms: D000293:Adolescent; D000328:Adult; D001931:Brain Mapping; D005260:Female; D005625:Frontal Lobe / Q000098:blood supply / Q000502:physiology*; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007802:Language; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D010100:Oxygen / Q000097:blood; D010296:Parietal Lobe / Q000098:blood supply / Q000502:physiology*
chemical_list: D010100:Oxygen