Ranzini Mariagrazia, Carbè Katia, Gevers Wim
AB&C, CRCN, Université Libre de Bruxelles (ULB), Belgium.
AB&C, CRCN, Université Libre de Bruxelles (ULB), Belgium.
Neuropsychologia. 2017 May;99:225-235. doi: 10.1016/j.neuropsychologia.2017.03.009. Epub 2017 Mar 6.
Number interval bisection consists of estimating the mid-number within a pair (1-9=>5). Healthy adults and right-brain damage patients can show biased performance in this task, underestimating and overestimating the mid-number, respectively. The role of visuospatial attention during this task, and its interplay with other cognitive abilities (e.g., working memory) is still object of debate. In this study we explored the relation between visuospatial attention and individual differences in working memory and executive functions during number interval bisection. To manipulate the deployment of visuospatial attention, healthy participants tracked a dot moving to the left or moving to the right while bisecting numerical intervals. We also collected information concerning verbal and visuospatial short-term memory span, and concerning verbal and visuospatial fluency scores. Beside replicating what is typically observed in this task (e.g., underestimation bias), a correlation was observed between verbal short-term memory and bisection bias, and an interesting relation between performance in the number interval bisection, verbal short-term memory, and visuospatial attention. Specifically, performance of those participants with low verbal span was affected by the direction of the moving dot, underestimating at a larger extent when the dot moved leftward than rightward. Finally, it was also observed that participants' verbal fluency ability contributed in the generation of biases in the numerical task. The finding of the involvement of abilities belonging to the verbal domain contributes to unveil the multi-componential nature of number interval bisection. Considering the debate on the nature of number interval bisection and its use in the clinical assessment of deficits following brain damage, this finding may be interesting also from a clinical perspective.
数字区间二等分包括估计一对数字中的中间数字（1 - 9 => 5）。健康成年人和右脑损伤患者在这项任务中可能表现出偏差，分别低估和高估中间数字。在这项任务中视觉空间注意力的作用及其与其他认知能力（如工作记忆）的相互作用仍是争论的焦点。在本研究中，我们探讨了数字区间二等分过程中视觉空间注意力与工作记忆和执行功能个体差异之间的关系。为了操纵视觉空间注意力的分配，健康参与者在对数字区间进行二等分时追踪向左或向右移动的点。我们还收集了有关言语和视觉空间短期记忆广度以及言语和视觉空间流畅性分数的信息。除了重复该任务中通常观察到的情况（如低估偏差）外，还观察到言语短期记忆与二等分偏差之间存在相关性，以及数字区间二等分表现、言语短期记忆和视觉空间注意力之间存在有趣的关系。具体而言，言语广度较低的参与者的表现受移动点方向的影响，当点向左移动时比向右移动时更大程度地低估。最后，还观察到参与者的言语流畅性能力在数字任务偏差的产生中起作用。属于言语领域的能力参与其中这一发现有助于揭示数字区间二等分的多成分性质。考虑到关于数字区间二等分的性质及其在脑损伤后缺陷临床评估中的应用的争论，这一发现从临床角度来看可能也很有趣。
