客体工作记忆任务中大脑皮层活动的记忆负荷效应

Effects of Memory Load of Brain Activation in Object Working Memory Task

利用128导事件相关电位技术，采用延迟匹配任务的实验范式，测查了20名正常被试完成不同负荷客体任务时的皮层慢电位(slow cortical potentials，简称sp成分)，实验发现：背侧前额叶在刺激呈现后的700m s到1400m s出现记忆负荷效应，高负荷任务诱发的sp成分显著负于低负荷任务；低负荷任务诱发的sp成分在左前额区(500~1800m s)、左前额-中央区(700~1800m s)、左中央-顶叶区(1000~1400 s和1800~4800m s)、右前额区(1800~4800m s)和右前额-中央区(1400~4800m s)显著负于高负荷任务，出现记忆负荷效应，但这种负荷效应在左右大脑半球所反映的心理意义可能不同。

Since the mid-1990s，psychologists and cognitive neuroscientists have been investigating in the area of object working memory and have gained valuable insights into the field. However， many issues and problems still need research attention. For example， there are different views concerning the dynamic change pattern of brain activation and the brain mechanism in object working memory tasks， and how the pattern of brain activation in high-load object working memory tasks differs from that in low-load tasks. The present study aimed to make use of the spatial-temporal properties of ERP slow waves to examine the pattern of brain activation when object information with different memory load was recoded and retained in WM.