Mandzia Jennifer L, Black Sandra E, McAndrews Mary Pat, Grady Cheryl, Graham Simon
Cognitive Neurology Unit and Imaging Research, Sunnybrook and Women's College Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
Hum Brain Mapp. 2004 Jan;21(1):1-14. doi: 10.1002/hbm.10140.
Functional MRI (fMRI) was used to examine the neural correlates of depth of processing during encoding and retrieval of photographs in older normal volunteers (n = 12). Separate scans were run during deep (natural vs. man-made decision) and shallow (color vs. black-and-white decision) encoding and during old/new recognition of pictures initially presented in one of the two encoding conditions. A baseline condition consisting of a scrambled, color photograph was used as a contrast in each scan. Recognition accuracy was greater for the pictures on which semantic decisions were made at encoding, consistent with the expected levels of processing effect. A mixed-effects model was used to compare fMRI differences between conditions (deep-baseline vs. shallow-baseline) in both encoding and retrieval. For encoding, this contrast revealed greater activation associated with deep encoding in several areas, including the left parahippocampal gyrus (PHG), left middle temporal gyrus, and left anterior thalamus. Increased left hippocampal, right dorsolateral, and inferior frontal activations were found for recognition of items that had been presented in the deep relative to the shallow encoding condition. We speculate that the modulation of activity in these regions by the depth of processing manipulation shows that these regions support effective encoding and successful retrieval. A direct comparison between encoding and retrieval revealed greater activation during retrieval in the medial temporal (right hippocampus and bilateral PHG), anterior cingulate, and bilateral prefrontal (inferior and dorsolateral). Most notably, greater right posterior PHG was found during encoding compared to recognition. Focusing on the medial temporal lobe (MTL) region, our results suggest a greater involvement of both anterior MTL and prefrontal regions in retrieval compared to encoding.
功能性磁共振成像（fMRI）被用于研究12名正常老年志愿者在对照片进行编码和检索过程中，加工深度的神经关联。在深度编码（自然与人工判断）和浅度编码（颜色与黑白判断）过程中以及对最初在两种编码条件之一中呈现的图片进行新旧识别时，分别进行扫描。每次扫描均使用由打乱的彩色照片组成的基线条件作为对照。对于在编码时做出语义判断的图片，识别准确率更高，这与预期的加工效果水平一致。使用混合效应模型比较编码和检索过程中不同条件（深度基线与浅度基线）之间的fMRI差异。在编码过程中，这种对比显示在包括左侧海马旁回（PHG）、左侧颞中回和左侧前丘脑在内的几个区域，与深度编码相关的激活更强。对于在深度编码条件下呈现的项目，相对于浅度编码条件，在识别时发现左侧海马、右侧背外侧和额下回的激活增加。我们推测，加工深度操作对这些区域活动的调节表明这些区域支持有效的编码和成功的检索。编码和检索之间的直接比较显示，在内侧颞叶（右侧海马和双侧PHG）、前扣带回和双侧前额叶（额下和背外侧），检索过程中的激活更强。最值得注意的是，与识别相比，编码过程中右侧海马旁回后部的激活更强。聚焦于内侧颞叶（MTL）区域，我们的结果表明，与编码相比，MTL前部和前额叶区域在检索过程中的参与度更高。
