Ferko Kayla M, Blumenthal Anna, Martin Chris B, Proklova Daria, Minos Alexander N, Saksida Lisa M, Bussey Timothy J, Khan Ali R, Köhler Stefan
Brain and Mind Institute, University of Western Ontario, London, Canada.
Robarts Research Institute Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada.
Elife. 2022 Mar 21;11:e66884. doi: 10.7554/eLife.66884.
Vision neuroscience has made great strides in understanding the hierarchical organization of object representations along the ventral visual stream (VVS). How VVS representations capture fine-grained visual similarities between objects that observers subjectively perceive has received limited examination so far. In the current study, we addressed this question by focussing on perceived visual similarities among subordinate exemplars of real-world categories. We hypothesized that these perceived similarities are reflected with highest fidelity in neural activity patterns downstream from inferotemporal regions, namely in perirhinal (PrC) and anterolateral entorhinal cortex (alErC) in the medial temporal lobe. To address this issue with functional magnetic resonance imaging (fMRI), we administered a modified 1-back task that required discrimination between category exemplars as well as categorization. Further, we obtained observer-specific ratings of perceived visual similarities, which predicted behavioural discrimination performance during scanning. As anticipated, we found that activity patterns in PrC and alErC predicted the structure of perceived visual similarity relationships among category exemplars, including its observer-specific component, with higher precision than any other VVS region. Our findings provide new evidence that subjective aspects of object perception that rely on fine-grained visual differentiation are reflected with highest fidelity in the medial temporal lobe.
视觉神经科学在理解沿腹侧视觉通路（VVS）的物体表征层次组织方面取得了长足进展。到目前为止，VVS表征如何捕捉观察者主观感知到的物体之间的细粒度视觉相似性受到的研究有限。在当前的研究中，我们通过关注现实世界类别下属范例之间的感知视觉相似性来解决这个问题。我们假设这些感知到的相似性在颞下区域下游的神经活动模式中得到最高保真度的反映，即在颞叶内侧的鼻周皮层（PrC）和前外侧内嗅皮层（alErC）中。为了通过功能磁共振成像（fMRI）解决这个问题，我们实施了一项修改后的1-back任务，该任务需要对类别范例进行区分以及分类。此外，我们获得了观察者特定的感知视觉相似性评分，这些评分预测了扫描期间的行为辨别表现。正如预期的那样，我们发现PrC和alErC中的活动模式比任何其他VVS区域更精确地预测了类别范例之间感知到的视觉相似性关系的结构，包括其观察者特定成分。我们的研究结果提供了新的证据，表明依赖于细粒度视觉区分的物体感知的主观方面在颞叶内侧得到最高保真度的反映。
