Department of Psychology, Educational Neuroscience, University of Graz, Graz, Austria.
PLoS One. 2024 Mar 21;19(3):e0301228. doi: 10.1371/journal.pone.0301228. eCollection 2024.
Determining if a sequence of numbers is ordered or not is one of the fundamental aspects of numerical processing linked to concurrent and future arithmetic skills. While some studies have explored the neural underpinnings of order processing using functional magnetic resonance imaging, our understanding of electrophysiological correlates is comparatively limited. To address this gap, we used a three-item symbolic numerical order verification task (with Arabic numerals from 1 to 9) to study event-related potentials (ERPs) in 73 adult participants in an exploratory approach. We presented three-item sequences and manipulated their order (ordered vs. unordered) as well as their inter-item numerical distance (one vs. two). Participants had to determine if a presented sequence was ordered or not. They also completed a speeded arithmetic fluency test, which measured their arithmetic skills. Our results revealed a significant mean amplitude difference in the grand average ERP waveform between ordered and unordered sequences in a time window of 500-750 ms at left anterior-frontal, left parietal, and central electrodes. We also identified distance-related amplitude differences for both ordered and unordered sequences. While unordered sequences showed an effect in the time window of 500-750 ms at electrode clusters around anterior-frontal and right-frontal regions, ordered sequences differed in an earlier time window (190-275 ms) in frontal and right parieto-occipital regions. Only the mean amplitude difference between ordered and unordered sequences showed an association with arithmetic fluency at the left anterior-frontal electrode. While the earlier time window for ordered sequences is consistent with a more automated and efficient processing of ordered sequential items, distance-related differences in unordered sequences occur later in time.
确定数字序列是否有序是与并发和未来算术技能相关的数值处理的基本方面之一。虽然一些研究已经使用功能磁共振成像探索了顺序处理的神经基础，但我们对电生理相关性的理解相对有限。为了解决这一差距，我们使用了一个三项目符号数字顺序验证任务（使用从 1 到 9 的阿拉伯数字），以探索性方法研究了 73 名成年参与者的事件相关电位（ERP）。我们呈现了三项目序列，并操纵了它们的顺序（有序与无序）以及它们的项目间数字距离（一个与两个）。参与者必须确定呈现的序列是否有序。他们还完成了一项快速算术流畅性测试，该测试衡量了他们的算术技能。我们的结果显示，在左前额、左顶和中央电极的 500-750ms 时间窗口内，有序和无序序列的平均 ERP 波形存在显著的平均振幅差异。我们还确定了有序和无序序列的距离相关振幅差异。虽然无序序列在电极簇的 500-750ms 时间窗口内显示出效应，这些电极簇位于前额和额区，但有序序列在额区和右顶枕区的较早时间窗口（190-275ms）内存在差异。只有有序和无序序列之间的平均振幅差异与左前额电极的算术流畅性有关。虽然有序序列的较早时间窗口与有序顺序项目的更自动和高效处理一致，但无序序列的距离相关差异发生在较晚的时间。
