Crespo-Facorro B, Wiser A K, Andreasen N C, O'Leary D S, Watkins G L, Boles Ponto L L, Hichwa R D
Mental Health-Clinical Research Center, Department of Psychiatry, College of Medicine, University of Iowa, Iowa City, Iowa 52242, USA.
Hum Brain Mapp. 2001 Apr;12(4):219-31. doi: 10.1002/1097-0193(200104)12:4<219::aid-hbm1017>3.0.co;2-l.
The level of familiarity of a given stimulus plays an important role in memory processing. Indeed, the novelty/familiarity of learned material has been proven to affect the pattern of activations during recognition memory tasks. We used visually presented words to investigate the neural basis of recognition memory for relatively novel and familiar stimuli in schizophrenia. Subjects were 34 healthy volunteers and 19 schizophrenia spectrum patients. Two experimental cognitive conditions were used: 1 week and again 1 day prior to the PET imaging subjects had to thoroughly learn a list of 18 words (well-learned memory). Subjects were also asked to learn another set of 18 words presented 1 min before the PET experiment (novel memory). During the PET session, subjects had to recognize the list of 18 words among 22 new (distractor) words. Subjects also performed a control task (reading words). A nonparametric randomization test and a statistical t-mapping method were used to determine between- and within-group differences. In patients the recognition of novel material produced relatively less flow in several frontal areas, superior temporal gyrus, insular cortex, and parahippocampal areas, and relatively higher activity in parietal areas, visual cortex, and cerebellum, compared to controls. No significant differences in flow were seen when comparing well-learned memory activations between groups. These results suggest that different neural pathways are engaged during novel recognition memory in patients with schizophrenia compared to healthy individuals. During recognition of novel material, patients failed to activate frontal/limbic regions, recruiting a set of posterior perceptual brain regions instead.
特定刺激的熟悉程度在记忆处理中起着重要作用。事实上，已证明所学材料的新颖性/熟悉性会影响识别记忆任务期间的激活模式。我们使用视觉呈现的单词来研究精神分裂症患者对相对新颖和熟悉刺激的识别记忆的神经基础。受试者包括34名健康志愿者和19名精神分裂症谱系患者。使用了两种实验性认知条件：在PET成像前1周和1天，受试者必须彻底学习一组18个单词（充分学习的记忆）。还要求受试者学习在PET实验前1分钟呈现的另一组18个单词（新颖记忆）。在PET扫描期间，受试者必须在22个新的（干扰）单词中识别出这组18个单词。受试者还执行了一个对照任务（阅读单词）。使用非参数随机化检验和统计t映射方法来确定组间和组内差异。与对照组相比，患者对新颖材料的识别在几个额叶区域、颞上回、岛叶皮质和海马旁区域产生的血流量相对较少，而在顶叶区域、视觉皮质和小脑产生的活动相对较高。比较两组之间充分学习的记忆激活时，未发现血流量有显著差异。这些结果表明，与健康个体相比，精神分裂症患者在新颖识别记忆过程中涉及不同的神经通路。在识别新颖材料时，患者未能激活额叶/边缘区域，而是激活了一组后部感知脑区。
