Murray Scott O, Wojciulik Ewa
Center for Neuroscience, University of California, Davis, Davis, California 95616, USA.
Nat Neurosci. 2004 Jan;7(1):70-4. doi: 10.1038/nn1161. Epub 2003 Nov 30.
It is well established that attention increases the efficiency of information processing, but the neural mechanisms underlying this improvement are not fully understood. Evidence indicates that neural firing rates increase for attended stimuli, but another possibility is that attention could increase the selectivity of the neural population representing an attended stimulus. We tested this latter hypothesis by using functional magnetic resonance imaging (fMRI) to measure population selectivity for object views under different attention conditions in the human lateral occipital complex (LOC). Our data not only show increased neural activity (or 'gain') with attention, consistent with existing models, but also increased population selectivity that cannot be accounted for by gain mechanisms alone. Our results suggest that attention increases the specificity of the neural population representing an attended object.
众所周知，注意力能提高信息处理效率，但其背后的神经机制尚未完全明晰。有证据表明，对于被关注的刺激，神经放电率会增加，但另一种可能性是，注意力可能会提高代表被关注刺激的神经群体的选择性。我们通过功能磁共振成像（fMRI）来测试后一种假设，以测量人类枕叶外侧复合体（LOC）在不同注意力条件下对物体视图的群体选择性。我们的数据不仅显示出注意力会使神经活动增加（或“增益”），这与现有模型一致，而且还显示出群体选择性增加，而这无法仅由增益机制来解释。我们的结果表明，注意力提高了代表被关注物体的神经群体的特异性。
