Vogel Stephan E, Goffin Celia, Ansari Daniel
Numerical Cognition Laboratory, Department of Psychology, The University of Western Ontario, London, ON, Canada; Section of Educational Neuroscience, Department of Psychology, University of Graz, Graz, Austria.
Numerical Cognition Laboratory, Department of Psychology, The University of Western Ontario, London, ON, Canada.
Dev Cogn Neurosci. 2015 Apr;12:61-73. doi: 10.1016/j.dcn.2014.12.001. Epub 2014 Dec 10.
The way the human brain constructs representations of numerical symbols is poorly understood. While increasing evidence from neuroimaging studies has indicated that the intraparietal sulcus (IPS) becomes increasingly specialized for symbolic numerical magnitude representation over developmental time, the extent to which these changes are associated with age-related differences in symbolic numerical magnitude representation or with developmental changes in non-numerical processes, such as response selection, remains to be uncovered. To address these outstanding questions we investigated developmental changes in the cortical representation of symbolic numerical magnitude in 6- to 14-year-old children using a passive functional magnetic resonance imaging adaptation design, thereby mitigating the influence of response selection. A single-digit Arabic numeral was repeatedly presented on a computer screen and interspersed with the presentation of novel digits deviating as a function of numerical ratio (smaller/larger number). Results demonstrated a correlation between age and numerical ratio in the left IPS, suggesting an age-related increase in the extent to which numerical symbols are represented in the left IPS. Brain activation of the right IPS was modulated by numerical ratio but did not correlate with age, indicating hemispheric differences in IPS engagement during the development of symbolic numerical representation.
人类大脑构建数字符号表征的方式仍未得到充分理解。虽然神经影像学研究的证据越来越多，表明顶内沟（IPS）在发育过程中越来越专门用于符号数字大小的表征，但这些变化与符号数字大小表征中与年龄相关的差异或与非数字过程（如反应选择）的发育变化相关的程度仍有待揭示。为了解决这些悬而未决的问题，我们使用被动功能磁共振成像适应设计，研究了6至14岁儿童符号数字大小的皮质表征的发育变化，从而减轻了反应选择的影响。一个一位阿拉伯数字在电脑屏幕上反复呈现，并穿插呈现根据数字比例（较小/较大数字）变化的新数字。结果表明，左IPS中年龄与数字比例之间存在相关性，表明左IPS中符号数字的表征程度与年龄相关增加。右IPS的大脑激活受数字比例调节，但与年龄无关，表明在符号数字表征发展过程中，IPS参与存在半球差异。
