Abdelmotaleb Mohamed, Niemann Filip, Kocataş Harun, Caisachana Guevara Leonardo M, Shahbabaie Alireza, Malinowski Robert, Riemann Steffen, Fromm Anna Elisabeth, Hayek Dayana, Antonenko Daria, Meinzer Marcus, Flöel Agnes
Department of Neurology, University Medicine Greifswald, Greifswald, Germany.
Department of Psychology, Greifswald University, Greifswald, Germany.
Brain Behav. 2025 Jul;15(7):e70658. doi: 10.1002/brb3.70658.
Object-location memory (OLM) is essential for remembering the locations of objects within an environment and is often impaired in aging and neurodegenerative diseases. Transcranial direct current stimulation (tDCS) has shown promise for improving OLM, although study outcomes have varied considerably. This study aimed to identify key brain regions involved in OLM that may serve as stimulation targets for future tDCS research and to assess the test-retest reliability (TRR) of both behavioral and functional magnetic resonance imaging (fMRI) data.
Twenty healthy young adults (10 females; mean age = 25.0 years, standard deviation [SD] = 5.56) completed two task-based fMRI sessions using parallel versions of an OLM task. Participants learned associations between house images and their locations on a two-dimensional street map across four feedback-based learning stages. Sham tDCS was administered in both sessions using a focal 3 × 1 electrode montage. TRR was assessed using intraclass correlation coefficients (ICCs) for behavioral performance and task-related fMRI activation.
Behavioral data showed significant improvements in response accuracy (estimate = 0.211, p < 0.001) and a reduction in response latency (estimate = -0.050, p < 0.001) across learning stages. fMRI analysis revealed predominantly right-lateralized activation, including the right hippocampus, the fusiform gyrus, the precuneus, and the lateral temporo-occipital areas. Behavioral measures showed moderate to good TRR (accuracy ICC = 0.801; reaction time ICC = 0.705). Task-related fMRI activity demonstrated good-to-excellent TRR in key regions, including the fusiform and temporo-occipital cortices.
These findings support the validity of our OLM paradigm for assessing brain stimulation effects and highlight potential cortical targets for future tDCS interventions. The observed reliability of behavioral and neural measures further reinforces the utility of this protocol in crossover study designs.
物体位置记忆（OLM）对于记住环境中物体的位置至关重要，并且在衰老和神经退行性疾病中常常受损。经颅直流电刺激（tDCS）已显示出改善OLM的潜力，尽管研究结果差异很大。本研究旨在确定参与OLM的关键脑区，这些脑区可能作为未来tDCS研究的刺激靶点，并评估行为和功能磁共振成像（fMRI）数据的重测信度（TRR）。
20名健康年轻成年人（10名女性；平均年龄 = 25.0岁，标准差[SD] = 5.56）使用OLM任务的平行版本完成了两个基于任务的fMRI实验。参与者在四个基于反馈的学习阶段中学习房屋图像与其在二维街道地图上位置之间的关联。在两个实验中均使用聚焦的3×1电极蒙太奇施加伪tDCS。使用组内相关系数（ICC）评估行为表现和与任务相关的fMRI激活的TRR。
行为数据显示，在学习阶段，反应准确性有显著提高（估计值 = 0.211，p < 0.001），反应潜伏期缩短（估计值 = -0.050，p < 0.001）。fMRI分析显示主要为右侧化激活，包括右侧海马体、梭状回、楔前叶和外侧颞枕区。行为测量显示出中度至良好的TRR（准确性ICC = 0.801；反应时间ICC = 0.705）。与任务相关的fMRI活动在关键区域（包括梭状回和颞枕叶皮质）显示出良好至优异的TRR。
这些发现支持了我们用于评估脑刺激效果的OLM范式的有效性，并突出了未来tDCS干预的潜在皮质靶点。观察到的行为和神经测量的可靠性进一步加强了该方案在交叉研究设计中的实用性。
