Harvey Philippe-Olivier, Lepage Martin
Department of Psychiatry, McGill University, Montréal, Que. Douglas Mental Health University Institute, Montréal, Que., Canada.
J Psychiatry Neurosci. 2014 Mar;39(2):97-109. doi: 10.1503/jpn.130007.
Social dysfunction is a hallmark characteristic of schizophrenia. Part of it may stem from an inability to efficiently encode social information into memory and retrieve it later. This study focused on whether patients with schizophrenia show a memory boost for socially relevant information and engage the same neural network as controls when processing social stimuli that were previously encoded into memory.
Patients with schizophrenia and healthy controls performed a social and nonsocial picture recognition memory task while being scanned. We calculated memory performance using d'. Our main analysis focused on brain activity associated with recognition memory of social and nonsocial pictures.
Our study included 28 patients with schizophrenia and 26 controls. Healthy controls demonstrated a memory boost for socially relevant information. In contrast, patients with schizophrenia failed to show enhanced recognition sensitivity for social pictures. At the neural level, patients did not engage the dorsomedial prefrontal cortex (DMPFC) as much as controls while recognizing social pictures.
Our study did not include direct measures of self-referential processing. All but 3 patients were taking antipsychotic medications, which may have altered both the behavioural performance during the picture recognition memory task and brain activity.
Impaired social memory in patients with schizophrenia may be associated with altered DMPFC activity. A reduction of DMPFC activity may reflect less involvement of self-referential processes during memory retrieval. Our functional MRI results contribute to a better mapping of the neural disturbances associated with social memory impairment in patients with schizophrenia and may facilitate the development of innovative treatments, such as transcranial magnetic stimulation.
社会功能障碍是精神分裂症的一个标志性特征。其部分原因可能是无法有效地将社会信息编码到记忆中并在之后检索出来。本研究聚焦于精神分裂症患者在处理先前已编码到记忆中的社会刺激时，是否对与社会相关的信息表现出记忆增强，以及是否与对照组激活相同的神经网络。
精神分裂症患者和健康对照组在接受扫描时执行一项社会和非社会图片识别记忆任务。我们使用d'来计算记忆表现。我们的主要分析集中在与社会和非社会图片识别记忆相关的大脑活动上。
我们的研究纳入了28名精神分裂症患者和26名对照组。健康对照组对与社会相关的信息表现出记忆增强。相比之下，精神分裂症患者对社会图片未能表现出增强的识别敏感性。在神经层面，患者在识别社会图片时背内侧前额叶皮层（DMPFC）的激活程度不如对照组。
我们的研究未包括自我参照加工的直接测量。除3名患者外，所有患者都在服用抗精神病药物，这可能改变了图片识别记忆任务期间的行为表现和大脑活动。
精神分裂症患者的社会记忆受损可能与DMPFC活动改变有关。DMPFC活动的减少可能反映出在记忆检索过程中自我参照过程的参与较少。我们的功能磁共振成像结果有助于更好地描绘与精神分裂症患者社会记忆障碍相关的神经紊乱，并可能促进创新治疗方法的发展，如经颅磁刺激。
