Crafa Daina, Hawco Colin, Brodeur Mathieu B
Integrated Program in Neuroscience, McGill University, Montreal, QC, Canada.
Campbell Family Mental Health Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada.
Front Behav Neurosci. 2017 Dec 14;11:232. doi: 10.3389/fnbeh.2017.00232. eCollection 2017.
Context sometimes helps make objects more recognizable. Previous studies using functional magnetic resonance imaging (fMRI) have examined regional neural activity when objects have strong or weak associations with their contexts. Such studies have demonstrated that activity in the parahippocampal cortex (PHC) generally corresponds with strong associations between objects and their spatial contexts while retrosplenial cortex (RSC) activity is linked with episodic memory. However these studies investigated objects viewed in associated contexts, but the direct influence of scene on the perception of visual objects has not been widely investigated. We hypothesized that the PHC and RSC may only be engaged for congruent contexts in which the object could typically be found but not for neutral contexts. While in an fMRI scanner, 15 participants rated the recognizability of 152 photographic images of objects, presented within congruent and incongruent contexts. Regions of interest were created to examine PHC and RSC activity using a hypothesis-driven approach. Exploratory analyses were also performed to identify other regional activity. In line with previous studies, PHC and RSC activity emerged when objects were viewed in congruent contexts. Activity in the RSC, inferior parietal lobe (IPL) and fusiform gyrus also emerged. These findings indicate that different brain regions are employed when objects are meaningfully contextualized.
背景有时有助于使物体更易于辨认。以往使用功能磁共振成像（fMRI）的研究考察了物体与其背景有强关联或弱关联时的局部神经活动。此类研究表明，海马旁皮质（PHC）的活动通常与物体及其空间背景之间的强关联相对应，而压后皮质（RSC）的活动则与情景记忆相关。然而，这些研究调查的是在相关背景中看到的物体，而场景对视觉物体感知的直接影响尚未得到广泛研究。我们假设，PHC和RSC可能仅在物体通常能被找到的一致背景中被激活，而在中性背景中则不会。在功能磁共振成像扫描仪中，15名参与者对152张物体照片在一致和不一致背景下的可辨认性进行了评分。采用假设驱动的方法创建感兴趣区域，以检查PHC和RSC的活动。还进行了探索性分析以识别其他区域的活动。与以往研究一致，当物体在一致背景中被观察时，PHC和RSC的活动出现。RSC、顶下小叶（IPL）和梭状回也出现了活动。这些发现表明，当物体被赋予有意义的背景时，会使用不同的脑区。
