Cortical Hemodynamic Response Associated with Spatial Coding: A Near-Infrared Spectroscopy Study

Abiot Y. Derbie, Bolton Chau, Bess Lam, Yun hua Fang, Kin Hung Ting, Clive Y.H. Wong, Jing Tao, Li dian Chen, Chetwyn C.H. Chan (Corresponding Author)

Research output: Journal article publicationJournal articleAcademic researchpeer-review

5 Citations (Scopus)


Allocentric and egocentric are two types of spatial coding. Previous studies reported the dorsal attention network’s involvement in both types. To eliminate possible paradigm-specific confounds in the results, this study employed fine-grained cue-to-target paradigm to dissociate allocentric (aSC) and egocentric (eSC) spatial coding. Twenty-two participants completed a custom visuospatial task, and changes in the concentration of oxygenated hemoglobin (O2-Hb) were recorded using functional near-infrared spectroscopy (fNIRS). The least absolute shrinkage and selection operator-regularized principal component (LASSO-RPC) algorithm was used to identify cortical sites that predicted the aSC and eSC conditions’ reaction times. Significant changes in O2-Hb concentration in the right inferior parietal lobule (IPL) and post-central gyrus regions were common in both aSC and eSC. Results of inter-channel correlations further substantiate cortical activities in both conditions were predominantly over the right parieto-frontal areas. Together with right superior frontal gyrus areas be the reaction time neural correlates, the results suggest top-down attention and response-mapping processes are common to both spatial coding types. Changes unique to aSC were in clusters over the right intraparietal sulcus, right temporo-parietal junction, and left IPL. With the left pre-central gyrus region, be the reaction time neural correlate, aSC is likely to involve more orienting attention, updating of spatial information, and object-based response selection and inhibition than eSC. Future studies will use other visuospatial task designs for testing the robustness of the findings on spatial coding processes.

Original languageEnglish
Pages (from-to)207-220
Number of pages14
JournalBrain Topography
Issue number2
Publication statusPublished - 23 Jan 2021


  • Allocentric spatial coding
  • Attention
  • Egocentric spatial coding
  • Fnirs
  • Frames of reference
  • IPL
  • SFG
  • Top-down attention

ASJC Scopus subject areas

  • Anatomy
  • Radiological and Ultrasound Technology
  • Radiology Nuclear Medicine and imaging
  • Neurology
  • Clinical Neurology


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