The Mind Research Network, Pete and Nancy Domenici Hall, 1101 Yale Blvd. NE, Albuquerque, NM 87106, USA.
Neuroimage. 2011 Oct 15;58(4):1158-68. doi: 10.1016/j.neuroimage.2011.06.091. Epub 2011 Jul 7.
The hippocampus has long been known to be important for memory, with the right hippocampus particularly implicated in nonverbal/visuo-spatial memory and the left in verbal/narrative or episodic memory. Despite this hypothesized lateralized functional difference, there has not been a single task that has been shown to activate both the right and left hippocampi differentially, dissociating the two, using neuroimaging. The transverse patterning (TP) task is a strong candidate for this purpose, as it has been shown in human and nonhuman animal studies to theoretically and empirically depend on the hippocampus. In TP, participants choose between stimuli presented in pairs, with the correct choice being a function of the specific pairing. In this project, TP was used to assess lateralized hippocampal function by varying its dependence on verbal material, with the goal of dissociating the two hippocampi. Magnetoencephalographic (MEG) data were collected while controls performed verbal and nonverbal versions of TP in order to verify and validate lateralized activation within the hippocampi. Schizophrenia patients were evaluated to determine whether they exhibited a lateralized hippocampal deficit. As hypothesized, patients' mean level of behavioral performance was poorer than controls' on both verbal and nonverbal TP. In contrast, patients had no decrement in performance on a verbal and nonverbal non-hippocampal-dependent matched control task. Also, controls but not patients showed more right hippocampal activation during nonverbal TP and more left hippocampal activation during verbal TP. These data demonstrate the capacity to assess lateralized hippocampal function and suggest a bilateral hippocampal behavioral and activation deficit in schizophrenia.
海马体长期以来一直被认为对记忆很重要，右侧海马体尤其与非语言/视空间记忆有关，而左侧海马体与语言/叙事或情景记忆有关。尽管有这种假设的侧化功能差异，但到目前为止，还没有一项任务能够在神经影像学上显示出右侧和左侧海马体的差异激活，从而分离这两个海马体。横向模式（TP）任务是一个很好的候选任务，因为它在人类和非人类动物研究中都被证明在理论上和经验上依赖于海马体。在 TP 中，参与者在成对呈现的刺激之间做出选择，正确的选择是特定配对的函数。在这个项目中，通过改变其对言语材料的依赖程度，使用 TP 来评估海马体的侧化功能，目的是分离两个海马体。在控制组执行言语和非言语版本的 TP 时，收集了脑磁图（MEG）数据，以验证和验证海马体中的侧化激活。评估精神分裂症患者是否表现出侧化海马体缺陷。正如假设的那样，患者在言语和非言语 TP 上的平均行为表现都比对照组差。相比之下，患者在言语和非言语非海马体依赖的匹配对照组任务上的表现没有下降。此外，只有对照组而不是患者在非言语 TP 中表现出更多的右侧海马体激活，在言语 TP 中表现出更多的左侧海马体激活。这些数据表明有能力评估侧化海马体功能，并表明精神分裂症中存在双侧海马体行为和激活缺陷。
