Dipartimento di Psicologia 39, Università Degli Studi di Roma ' Sapienza', Roma, Italy; Fondazione Santa Lucia IRCCS, Roma, Italy.
Area of Neuroscience, SISSA, Trieste, Italy.
Cortex. 2018 Apr;101:1-15. doi: 10.1016/j.cortex.2017.12.015. Epub 2018 Jan 2.
Inspecting or transforming the position of Arabic numbers in mental space helps everyday mathematical calculations. Nonetheless the neural and functional bases of this ability are poorly understood. Here we show that imagining the position of Arabic numbers on a horizontal mental number line speeds up the detection of targets appearing at corresponding positions in visual space. No similar advantage is found when numbers are merely perceived or classified according to their magnitude. Imagery enhanced electrophysiological activity in the extrastriate cortex contralateral to the imagined number position. Speeded detection of targets that were spatially congruent with the imagined number position was matched with enhanced C1 responses in primary visual cortex. In contrast, imagery had no effect on later target-related responses that are usually modulated by spatial attention. These results shed new light on the mechanisms that evoke sensory-like spatial representations of Arabic numbers in everyday mental computations.
在心理空间中检查或转换阿拉伯数字的位置有助于日常的数学计算。尽管如此，这种能力的神经和功能基础还知之甚少。在这里，我们表明，想象阿拉伯数字在水平心理数字线上的位置会加快对出现在视觉空间中相应位置的目标的检测。当数字仅根据其大小进行感知或分类时，不会发现类似的优势。想象增强了对侧外纹状皮层中与想象数字位置相对应的电生理活动。与想象中的数字位置空间一致的目标的检测速度加快与初级视觉皮层中 C1 反应的增强相匹配。相比之下，想象对通常由空间注意力调节的后期目标相关反应没有影响。这些结果为在日常心理计算中引发阿拉伯数字的感觉样空间表示的机制提供了新的线索。
