Clark C Richard, McFarlane Alexander C, Morris Philip, Weber Darren L, Sonkkilla Cynon, Shaw Marnie, Marcina Jackie, Tochon-Danguy H J, Egan Gary F
School of Psychology, Flinders Medical Research Institute, Flinders University, Adelaide, Australia.
Biol Psychiatry. 2003 Mar 15;53(6):474-81. doi: 10.1016/s0006-3223(02)01505-6.
This study examined cerebral function in posttraumatic stress disorder (PTSD) during the updating of working memory to trauma-neutral, verbal information.
Ten PTSD and matched control subjects completed a visuoverbal target detection task involving continuous updating (Variable target condition) or no updating (Fixed target condition) of target identity, with updating activity estimated by condition comparison.
Normal updating activity using this paradigm involved bilateral activation of the dorsolateral prefrontal cortex (DLPFC) and inferior parietal lobe. The PTSD group lacked this activation in the left hemisphere and was significantly different from control subjects in this regard, but showed additional activation in the superior parietal lobe, bilaterally.
The pattern of parietal activation suggests a dependence on visuospatial coding for working memory representation of trauma-neutral, verbal information. Group differences in the relative involvement of the DLPFC indicate less dependence in PTSD on the executive role normally attributed to the left DLPFC for monitoring and manipulation of working memory content in posterior regions of the brain.
本研究在将工作记忆更新为创伤中性的言语信息过程中，对创伤后应激障碍（PTSD）患者的脑功能进行了检测。
10名PTSD患者及匹配的对照受试者完成了一项视觉言语目标检测任务，该任务涉及目标身份的持续更新（可变目标条件）或不更新（固定目标条件），通过条件比较来估计更新活动。
使用该范式的正常更新活动涉及双侧背外侧前额叶皮层（DLPFC）和顶下叶的激活。PTSD组左半球缺乏这种激活，在这方面与对照受试者有显著差异，但双侧顶叶上部显示出额外激活。
顶叶激活模式表明，对于创伤中性言语信息的工作记忆表征，依赖于视觉空间编码。DLPFC相对参与程度的组间差异表明，PTSD患者对通常归因于左DLPFC在大脑后部区域监测和操纵工作记忆内容的执行作用的依赖性较低。
