Distinct Cerebral Pathways for Object Identity and Number in Human Infants

All humans, regardless of their culture and education, possess an intuitive understanding of number. Behavioural evidence suggests that numerical competence may be present early on in infancy. Here, we present brain-imaging evidence for distinct cerebral coding of number and object identity in 3-mo-old infants. We compared the visual event-related potentials evoked by unforeseen changes either in the identity of objects forming a set, or in the cardinal of this set. In adults and 4-y-old children, number sense relies on a dorsal system of bilateral intraparietal areas, different from the ventral occipitotemporal system sensitive to object identity. Scalp voltage topographies and cortical source modelling revealed a similar distinction in 3-mo-olds, with changes in object identity activating ventral temporal areas, whereas changes in number involved an additional right parietoprefrontal network. These results underscore the developmental continuity of number sense by pointing to early functional biases in brain organization that may channel subsequent learning to restricted brain areas.

无论文化背景与受教育程度如何，所有人类都具备对数字的直觉认知。行为学证据表明，数字认知能力可能在婴儿早期就已存在。本研究提供了脑成像证据，证实3月龄婴儿的大脑对数字与物体身份存在差异化编码。我们对比了两类意外变化所诱发的视觉事件相关电位（visual event-related potentials）：一类是组成集合的物体身份发生改变，另一类是该集合的基数（即数量）发生变化。对于成人与4岁儿童而言，数字认知依赖于由双侧顶内区（intraparietal areas）构成的背侧通路，该通路与对物体身份敏感的腹侧枕颞通路截然不同。头皮电压地形图与脑电源建模结果显示，3月龄婴儿同样存在类似的功能分化：物体身份变化会激活腹侧颞叶区域，而数量变化则会额外激活右侧顶叶-前额叶网络（parietoprefrontal network）。上述研究结果表明，大脑组织在早期就已存在功能偏向，这种偏向可引导后续学习限定在特定脑区范围内，从而证实了数字认知能力的发育连续性。