What Makes Different People's Representations Alike: Neural Similarity Space Solves the Problem of Across-subject fMRI Decoding
What Makes Different People's Representations Alike: Neural Similarity Space Solves the Problem of Across-subject fMRI Decoding
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DOI：
10.1162/jocn_a_00189
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发表时间：
2012-04-01
影响因子：
3.2
通讯作者：
Connolly, Andrew C.
中科院分区：
文献类型：
--
作者：
Raizada, Rajeev D. S.;Connolly, Andrew C.
神经科学的一个中心目标是解释神经激活，而且，以一种通过对个体进行概括来捕捉普遍原则的方式来解释神经激活。最近在基于多体素模式的fMRI分析方面的研究已经在个体对象内的解码方面取得了相当大的成功。然而，能够跨受试者进行解码的目标仍然具有挑战性：目前还不清楚神经表征在人群水平上可能存在什么规律。在这里，我们提出了一个新的和高精度的解决方案，它可以在八种不同的刺激条件下对受试者进行解码。找到这个解决方案的关键是质疑一个看似显而易见的想法，即神经解码应该直接作用于神经激活模式。相反，对于跨主题的解码，从特定于主题的神经活动模式中抽象出来是有益的，相反，对这些模式之间的相似关系进行操作：我们的新方法纯粹在相似空间内进行解码。这些结果证明了一种迄今未知的群体水平的神经表征规律性，也揭示了我们在功能磁共振成像中的经验发现与心灵哲学中关于神经多样性概念相似性问题的讨论之间的惊人趋同。
A central goal in neuroscience is to interpret neural activation and, moreover, to do so in a way that captures universal principles by generalizing across individuals. Recent research in multi-voxel pattern-based fMRI analysis has led to considerable success at decoding within individual subjects. However, the goal of being able to decode across subjects is still challenging: It has remained unclear what population-level regularities of neural representation there might be. Here, we present a novel and highly accurate solution to this problem, which decodes across subjects between eight different stimulus conditions. The key to finding this solution was questioning the seemingly obvious idea that neural decoding should work directly on neural activation patterns. On the contrary, to decode across subjects, it is beneficial to abstract away from subject-specific patterns of neural activity and, instead, to operate on the similarity relations between those patterns: Our new approach performs decoding purely within similarity space. These results demonstrate a hitherto unknown population-level regularity in neural representation and also reveal a striking convergence between our empirical findings in fMRI and discussions in the philosophy of mind addressing the problem of conceptual similarity across neural diversity.