Applied Cognitive Neuroscience Laboratory, Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China.
Department of Psychology, Bahir Dar University, Bahir Dar, Ethiopia.
Brain Topogr. 2021 Mar;34(2):207-220. doi: 10.1007/s10548-021-00821-9. Epub 2021 Jan 23.
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 (O-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 O-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.
无向性和自我中心性是两种空间编码类型。先前的研究报告了背侧注意网络在这两种类型中都有参与。为了消除结果中可能存在的特定范式混淆，本研究采用了精细的线索到目标范式来区分无向性（aSC）和自我中心性（eSC）空间编码。22 名参与者完成了一项定制的视空间任务，并使用功能近红外光谱（fNIRS）记录了含氧血红蛋白（O-Hb）浓度的变化。最小绝对值收缩和选择算子正则化主成分（LASSO-RPC）算法用于识别预测 aSC 和 eSC 条件反应时间的皮质位点。右顶下小叶（IPL）和后中央回区域的 O-Hb 浓度的显著变化在 aSC 和 eSC 中都很常见。通道间相关性的结果进一步证实，两种条件下的皮质活动主要集中在右顶额区域。与右额上回区域一起作为反应时间的神经相关物，结果表明自上而下的注意和反应映射过程是两种空间编码类型共有的。aSC 特有的变化发生在右顶内沟、右颞顶联合区和左 IPL 的集群中。与左中央前回区域一起作为反应时间的神经相关物，aSC 可能比 eSC 涉及更多的定向注意、空间信息更新以及基于对象的反应选择和抑制。未来的研究将使用其他视空间任务设计来测试这些空间编码过程发现的稳健性。
