客体复杂度影响工作记忆可存储的客体数目

采用变化觉察范式，以对侧延迟活动（contralateral delay activity，CDA）的幅值为指标，通过操纵记忆刺激的复杂程度，对视觉工作记忆中可存储的客体数目（即工作记忆容量）问题进行了探讨。结果表明，2个复杂客体条件下的CDA幅值与4个复杂客体条件无显著差异，而4个简单客体条件的CDA幅值显著高于2个简单客体条件，即CDA的幅值受客体复杂度的调节。基于该结果推论：并非视觉工作记忆总能存储4个客体，其可存储的客体数目受客体复杂度影响。

Object Complexity Influences the Number of Objects Stored in Visual Working Memory

Visual working memory （VWM）enables the on-line maintenance and manipulation of a limited amount of visual information. However, the capacity of VWM for visual information is still in controversy. One proposes that VWM can store a fixed number of objects regardless of object complexity. The other one argues that VWM capacity is a flexible resource, and there is an upper bound to the total amount of information in VWM. Here we reexamined the capacity of VWM by taking the contralateral delay activity （CDA）, an event-related potential difference wave that reflects the number of objects being active in VWM, as an index to explore the capacity of VWM. Two kinds of stimuli with different levels of complexity, i. e. , basic shapes （ simple ） and random polygons （ complex ）, were adopted as materials. The result showed that the amplitude of CDA was modulated by object complexity. In particular, as the set size of memory array rose from 2 to d, the amplitude of CDA stopped increasing for random polygons, while continued increasing for simple objects. It is thus suggested VWM can＇ t always store 4 objects. The number of objects VWM can store is modulated by object complexity.