Section on Learning and Plasticity, Laboratory of Brain and Cognition, National Institute of Mental Health, Bethesda, MD 20892-1366, United States; Video and Image Sense Lab, Institute for Informatics, University of Amsterdam, Amsterdam, the Netherlands.
Section on Learning and Plasticity, Laboratory of Brain and Cognition, National Institute of Mental Health, Bethesda, MD 20892-1366, United States; Department of Psychology, School of Philosophy, Psychology and Language Sciences, The University of Edinburgh, Edinburgh, United Kingdom.
Neuroimage. 2021 Apr 15;230:117790. doi: 10.1016/j.neuroimage.2021.117790. Epub 2021 Jan 23.
Human visual cortex contains three scene-selective regions in the lateral, medial and ventral cortex, termed the occipital place area (OPA), medial place area (MPA) and parahippocampal place area (PPA). Using functional magnetic resonance imaging (fMRI), all three regions respond more strongly when viewing visual scenes compared with isolated objects or faces. To determine how these regions are functionally and causally connected, we applied transcranial magnetic stimulation to OPA and measured fMRI responses before and after stimulation, using a theta-burst paradigm (TBS). To test for stimulus category-selectivity, we presented a range of visual categories (scenes, buildings, objects, faces). To test for specificity of any effects to TBS of OPA we employed two control conditions: Sham, with no TBS stimulation, and an active TBS-control with TBS to a proximal face-selective cortical region (occipital face area, or OFA). We predicted that TBS to OPA (but not OFA) would lead to decreased responses to scenes and buildings (but not other categories) in other scene-selective cortical regions. Across both ROI and whole-volume analyses, we observed decreased responses to scenes in PPA as a result of TBS. However, these effects were neither category specific, with decreased responses to all stimulus categories, nor limited to scene-selective regions, with decreases also observed in face-selective fusiform face area (FFA). Furthermore, similar effects were observed with TBS to OFA, thus effects were not specific to the stimulation site in the lateral occipital cortex. Whilst these data are suggestive of a causal, but non-specific relationship between lateral occipital and ventral temporal cortex, we discuss several factors that could have underpinned this result, such as the differences between TBS and online TMS, the role of anatomical distance between stimulated regions and how TMS effects are operationalised. Furthermore, our findings highlight the importance of active control conditions in brain stimulation experiments to accurately assess functional and causal connectivity between specific brain regions.
人类视觉皮层在外侧、内侧和腹侧皮层中包含三个场景选择性区域，分别称为枕部位置区域（OPA）、内侧位置区域（MPA）和旁海马位置区域（PPA）。使用功能磁共振成像（fMRI），当观看视觉场景时，所有三个区域的反应都比单独的物体或面孔更强。为了确定这些区域在功能和因果上是如何连接的，我们应用经颅磁刺激（TMS）刺激 OPA，并使用 theta 爆发范式（TBS）在刺激前后测量 fMRI 反应。为了测试刺激类别选择性，我们呈现了一系列视觉类别（场景、建筑物、物体、面孔）。为了测试 TBS 对 OPA 的任何影响的特异性，我们采用了两种对照条件：假刺激，没有 TBS 刺激，以及使用 TBS 到近端面部选择性皮质区域（枕部面部区域，或 OFA）的活动 TBS 对照。我们预测，TBS 对 OPA（而不是 OFA）会导致其他场景选择性皮质区域对场景和建筑物的反应减少（但不是其他类别）。在 ROI 和全容积分析中，我们观察到 TBS 导致 PPA 对场景的反应减少。然而，这些影响既不是类别特异性的，对所有刺激类别都有反应减少，也不是仅限于场景选择性区域，在面孔选择性梭状回面孔区（FFA）也观察到减少。此外，用 OFA 的 TBS 也观察到类似的效果，因此，这些效果不是特定于外侧枕叶皮质的刺激部位。虽然这些数据表明外侧枕叶和腹侧颞叶皮质之间存在因果关系，但不具有特异性，但我们讨论了一些可能支持这一结果的因素，例如 TBS 和在线 TMS 之间的差异、刺激区域之间的解剖距离的作用以及 TMS 效应是如何运作的。此外，我们的研究结果强调了在脑刺激实验中使用活动对照条件的重要性，以准确评估特定脑区之间的功能和因果连通性。
