Ding Gangqiang, Ye Weidong, Cao Bihua, Li Fuhong
School of Psychology, Jiangxi Normal University, Nanchang, China.
School of Education, Xinyang College, Xinyang, China.
Psychophysiology. 2023 Jan;60(1):e14135. doi: 10.1111/psyp.14135. Epub 2022 Jul 1.
Previous studies have revealed the effect of set size (the number of activated items) on object switching in working memory, but the underlying neural mechanism remains unclear. In this study, participants were asked to first remember two (small size) or three (large size) two-digit numbers and the corresponding geometrical figures as different references for numerical comparison and then compare a series of numbers (10-99) to the reference numbers cued by different geometrical figures. The cue repeated or switched across trials. Behavioral results revealed that the switch cost was greater in the large-size condition than in the small-size condition. Event-related potential results showed that in the N2 component, an interaction was observed between set size and transition, with a significant transition effect (switch minus repeat) in the large-size condition and a non-significant transition effect in the small-size condition. The same interaction was observed in the P3 component, with a larger amplitude difference (switch minus repeat) in the large-size condition than in the small-size condition. These results suggested that when set size is increased, the effort to inhibit the irrelevant items increases, resulting in large cost of object switching in working memory.
以往的研究揭示了集合大小（激活项目的数量）对工作记忆中对象切换的影响，但其潜在的神经机制仍不清楚。在本研究中，参与者首先被要求记住两个（小集合大小）或三个（大集合大小）两位数以及相应的几何图形，作为数值比较的不同参考，然后将一系列数字（10 - 99）与由不同几何图形提示的参考数字进行比较。线索在试验中重复或切换。行为结果表明，大集合大小条件下的切换代价大于小集合大小条件下的切换代价。事件相关电位结果显示，在N2成分中，观察到集合大小和转换之间存在交互作用，大集合大小条件下有显著的转换效应（切换减去重复），而小集合大小条件下转换效应不显著。在P3成分中也观察到相同的交互作用，大集合大小条件下的幅度差异（切换减去重复）大于小集合大小条件下的幅度差异。这些结果表明，当集合大小增加时，抑制无关项目的努力增加，导致工作记忆中对象切换的代价增大。
