Kamitani Yukiyasu, Tong Frank
ATR Computational Neuroscience Laboratories, 2-2-2 Hikaridai, Keihanna Science City, Kyoto 619-0288, Japan.
Nat Neurosci. 2005 May;8(5):679-85. doi: 10.1038/nn1444. Epub 2005 Apr 24.
The potential for human neuroimaging to read out the detailed contents of a person's mental state has yet to be fully explored. We investigated whether the perception of edge orientation, a fundamental visual feature, can be decoded from human brain activity measured with functional magnetic resonance imaging (fMRI). Using statistical algorithms to classify brain states, we found that ensemble fMRI signals in early visual areas could reliably predict on individual trials which of eight stimulus orientations the subject was seeing. Moreover, when subjects had to attend to one of two overlapping orthogonal gratings, feature-based attention strongly biased ensemble activity toward the attended orientation. These results demonstrate that fMRI activity patterns in early visual areas, including primary visual cortex (V1), contain detailed orientation information that can reliably predict subjective perception. Our approach provides a framework for the readout of fine-tuned representations in the human brain and their subjective contents.
人类神经成像技术读出一个人心理状态详细内容的潜力尚未得到充分探索。我们研究了能否从功能磁共振成像（fMRI）测量的人类大脑活动中解码边缘方向这一基本视觉特征的感知。使用统计算法对大脑状态进行分类，我们发现早期视觉区域的fMRI信号总体能够在个体试验中可靠地预测受试者所看到的八个刺激方向中的哪一个。此外，当受试者必须关注两个重叠的正交光栅中的一个时，基于特征的注意力会强烈地使总体活动偏向被关注的方向。这些结果表明，包括初级视觉皮层（V1）在内的早期视觉区域的fMRI活动模式包含能够可靠预测主观感知的详细方向信息。我们的方法为读出人类大脑中微调后的表征及其主观内容提供了一个框架。
