Douglas Mental Health University Institute & Department of Psychiatry, McGill University, Montréal, Canada.
Psychiatry Res. 2010 Jun 30;182(3):191-9. doi: 10.1016/j.pscychresns.2010.03.002. Epub 2010 May 20.
People with schizophrenia consistently show memory impairment on varying tasks including item recognition memory. Relative to the correct rejection of distracter items, the correct recognition of studied items consistently produces an effect termed the old/new effect that is characterized by increased activity in parietal and frontal cortical regions. This effect has received only scant attention in schizophrenia. We examined the old/new effect in 15 people with schizophrenia and 18 controls during an item recognition test, and neural activity was examined with event-related functional magnetic resonance imaging. Both groups performed equally well during the recognition test and showed increased activity in a left dorsolateral prefrontal region and in the precuneus bilaterally during the successful recognition of old items relative to the correct rejection of new items. The control group also exhibited increased activity in the dorsal left parietal cortex. This region has been implicated in the top-down modulation of memory which involves control processes that support memory-retrieval search, monitoring and verification. Although these processes may not be of paramount importance in item recognition memory performance, the present findings suggest that people with schizophrenia may have difficulty with such top-down modulation, a finding consistent with many other studies in information processing.
精神分裂症患者在各种任务中（包括项目识别记忆）均表现出记忆障碍。与正确拒绝干扰项相比，正确识别学习过的项目会产生一种被称为“旧/新”效应的影响，其特征是顶叶和额叶皮质区域的活动增加。这种效应在精神分裂症中只受到了很少的关注。我们在项目识别测试中检查了 15 名精神分裂症患者和 18 名对照者的“旧/新”效应，并用事件相关功能磁共振成像来检查神经活动。两组在识别测试中表现相当，在成功识别旧项目相对于正确拒绝新项目时，左侧背外侧前额叶区域和双侧楔前叶的活动增加。对照组在左侧背顶叶皮层也表现出了活动增加。这个区域涉及支持记忆检索搜索、监测和验证的控制过程，被认为是记忆的自上而下调节的关键。尽管这些过程在项目识别记忆表现中可能不是最重要的，但目前的发现表明，精神分裂症患者可能难以进行这种自上而下的调节，这一发现与信息处理的许多其他研究一致。
