Center for the Neurobiology of Learning and Memory, Department of Neurobiology and Behavior, University of California at Irvine, Irvine, California 92697, USA.
Learn Mem. 2012 Nov 19;19(12):605-14. doi: 10.1101/lm.027631.112.
Functional magnetic resonance imaging (fMRI) was employed to identify neural regions engaged during the encoding of contextual features belonging to different modalities. Subjects studied objects that were presented to the left or right of fixation. Each object was paired with its name, spoken in either a male or a female voice. The test requirement was to discriminate studied from unstudied pictures and, for each picture judged old, to retrieve its study location and the gender of the voice that spoke its name. Study trials associated with accurate rather than inaccurate location memory demonstrated enhanced activity in the fusiform and parahippocampal cortex and the hippocampus and reduced activity (a negative subsequent memory effect) in the medial occipital cortex. Successful encoding of voice information was associated with enhanced study activity in the right middle superior temporal sulcus and activity reduction in the right superior frontal cortex. These findings support the proposal that encoding of a contextual feature is associated with enhanced activity in regions engaged during its online processing. In addition, they indicate that negative subsequent memory effects can also demonstrate feature-selectivity. Relative to other classes of study trials, trials for which both contextual features were later retrieved demonstrated enhanced activity in the lateral occipital complex and reduced activity in the temporo-parietal junction. These findings suggest that multifeatural encoding was facilitated when the study item was processed efficiently and study processing was not interrupted by redirection of attention toward extraneous events.
功能性磁共振成像 (fMRI) 被用于识别在编码属于不同模态的上下文特征时参与的神经区域。受试者研究呈现于注视点左侧或右侧的物体。每个物体都与其名称配对，名称由男性或女性声音说出。测试要求是区分学习过的和未学习过的图片，并且对于每个被判断为旧的图片，检索其学习位置和说出其名称的声音的性别。与准确的位置记忆而不是不准确的位置记忆相关的研究试验表现出梭状回和海马旁回以及海马体的活性增强，而内侧枕叶皮质的活性降低（负的后续记忆效应）。成功编码声音信息与右中颞上回的研究活动增强以及右额上回的活动减少有关。这些发现支持了这样的假设，即上下文特征的编码与在线处理过程中涉及的区域的活性增强有关。此外，它们表明负的后续记忆效应也可以表现出特征选择性。与其他类别的研究试验相比，当后来检索到上下文特征时，试验表现出外侧枕叶复合体的活性增强和颞顶联合区的活性降低。这些发现表明，当研究项目被有效地处理并且研究处理没有被注意力转向无关事件中断时，多特征编码得到了促进。
