title: Dissociation in accessing space and number representations in pathologic pain patients.
abstract: Space is represented by integrating egocentric and allocentric reference frames; however, little is known about the role of these independent reference frames in number representation. Using patients with unilateral pathologic pain in one limb, we investigated whether number representation is closely linked to space representation by evaluating visual subjective body-midline judgments in dark and light conditions (egocentric and allocentric space, respectively). To evaluate the number representation, pairs of numbers were read aloud to the participant, who was then asked to state the midpoint number that they intuitively perceived to be at the middle of each interval. All of the patients perceived allocentric space accurately in the light condition. However, each of the patients showed perceptual shifts in egocentric space and number representation in the dark as compared with control subjects. Direct comparison showed a consistent relationship between number representation and egocentric space. We suggest that numbers are represented spatially by integrating these independent reference frames.
authors.affiliation: Department of Pain and Palliative Medicine, The University of Tokyo Hospital, Japan; Department of Anesthesiology and Pain Relief Center, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan. Electronic address: sumitanim-ane@h.u-tokyo.ac.jp.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Sumitani
authors.affiliation: Kobe Advanced ICT Research Center, National Institute of Information and Communications Technology, 588-2, Iwaoka, Nishi-ku, Kobe, Hyogo 651-2492, Japan. Electronic address: mamisaki@gmail.com.
authors.forename: Masaya
authors.initials: M
authors.lastname: Misaki
authors.affiliation: Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan. Electronic address: skumagaya@hotmail.com.
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Kumagaya
authors.affiliation: Department of Rehabilitation for the Movement Functions, Research Institute, National Rehabilitation Center for Persons with Disabilities, 4-1 Namiki, Tokorozawa, Saitama 359-0042, Japan. Electronic address: ogata-toru@rehab.go.jp.
authors.forename: Toru
authors.initials: T
authors.lastname: Ogata
authors.affiliation: Department of Anesthesiology and Pain Relief Center, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan. Electronic address: yamaday-ane@h.u-tokyo.ac.jp.
authors.forename: Yoshitsugu
authors.initials: Y
authors.lastname: Yamada
authors.affiliation: Kobe Advanced ICT Research Center, National Institute of Information and Communications Technology, 588-2, Iwaoka, Nishi-ku, Kobe, Hyogo 651-2492, Japan. Electronic address: miyauchi@nict.go.jp.
authors.forename: Satoru
authors.initials: S
authors.lastname: Miyauchi
mesh_terms: D000328:Adult; D000368:Aged; D001828:Body Image; D020918:Complex Regional Pain Syndromes / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D055641:Mathematical Concepts; D008875:Middle Aged; D013028:Space Perception
keywords: Allocentric reference frame; Egocentric reference frame; Number representation; Pain; Space representation