Guggenmos Matthias, Thoma Volker, Haynes John-Dylan, Richardson-Klavehn Alan, Cichy Radoslaw Martin, Sterzer Philipp
Bernstein Center for Computational Neuroscience, Berlin, Germany; Visual Perception Laboratory, Charité Universitätsmedizin, Berlin, Germany.
School of Psychology, University of East London, London, UK.
Neuroimage. 2015 Aug 1;116:149-57. doi: 10.1016/j.neuroimage.2015.04.004. Epub 2015 Apr 10.
The modulation of neural activity in visual cortex is thought to be a key mechanism of visual attention. The investigation of attentional modulation in high-level visual areas, however, is hampered by the lack of clear tuning or contrast response functions. In the present functional magnetic resonance imaging study we therefore systematically assessed how small voxel-wise biases in object preference across hundreds of voxels in the lateral occipital complex were affected when attention was directed to objects. We found that the strength of attentional modulation depended on a voxel's object preference in the absence of attention, a pattern indicative of an amplificatory mechanism. Our results show that such attentional modulation effectively increased the mutual information between voxel responses and object identity. Further, these local modulatory effects led to improved information-based object readout at the level of multi-voxel activation patterns and to an increased reproducibility of these patterns across repeated presentations. We conclude that attentional modulation enhances object coding in local and distributed object representations of the lateral occipital complex.
视觉皮层中神经活动的调制被认为是视觉注意力的关键机制。然而，由于缺乏清晰的调谐或对比度响应函数，对高级视觉区域注意力调制的研究受到了阻碍。因此，在本功能磁共振成像研究中，我们系统地评估了当注意力指向物体时，枕外侧复合体中数百个体素在物体偏好上的微小体素级偏差是如何受到影响的。我们发现，注意力调制的强度取决于注意力缺失时体素的物体偏好，这一模式表明存在一种放大机制。我们的结果表明，这种注意力调制有效地增加了体素反应与物体身份之间的互信息。此外，这些局部调制效应导致在多体素激活模式水平上基于信息的物体读出得到改善，并使这些模式在重复呈现时的可重复性增加。我们得出结论，注意力调制增强了枕外侧复合体局部和分布式物体表征中的物体编码。
