Representational dynamics of object recognition: Feedforward and feedback information flows
Representational dynamics of object recognition: Feedforward and feedback information flows
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DOI：
10.1016/j.neuroimage.2016.01.006
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发表时间：
2016-03-01
期刊：
影响因子：
5.7
通讯作者：
Woolgar, Alexandra
中科院分区：
文献类型：
--
作者：
Goddard, Erin;Carlson, Thomas A.;Woolgar, Alexandra
物体感知涉及一系列视觉和认知过程，并且已知包括从早期视觉皮质区域到高级皮质区域的信息前向流动，以及来自前额叶皮质等区域的反馈，沿着。先前的研究已经发现，低和高空间频率信息的对象身份可能会在不同的时间尺度上处理。在这里，我们使用高时间分辨率的脑磁图（MEG）结合多元模式分析来测量信息，特别是有关对象的身份在额叶周围和枕叶周围地区。使用在其低水平视觉内容中紧密匹配的刺激，我们发现，枕周皮层中的活动可用于从类似于刺激开始后80 ms解码对象身份，并且额叶皮层中的活动也可用于从稍后的时间（类似于刺激开始后265 ms）解码对象身份。低空间频率的信息有关的对象身份存在于脑磁信号在较早的时间比高空间频率的信息，枕周皮层，但不为额叶皮层。我们还使用了格兰杰因果关系分析比较前馈和反馈的影响，表征内容，并发现证据的早期前馈流和后来的反馈流的信息有关的对象身份。我们讨论了我们的研究结果与现有的理论对象处理，并提出我们在这里使用的方法可以用来解决进一步的问题，对象感知的神经基板。(C)2016 Elsevier Inc. All rights reserved.
Object perception involves a range of visual and cognitive processes, and is known to include both a feedfoward flow of information from early visual cortical areas to higher cortical areas, along with feedback from areas such as prefrontal cortex. Previous studies have found that low and high spatial frequency information regarding object identity may be processed over different timescales. Here we used the high temporal resolution of magnetoencephalography (MEG) combined with multivariate pattern analysis to measure information specifically related to object identity in peri-frontal and peri-occipital areas. Using stimuli closely matched in their low-level visual content, we found that activity in peri-occipital cortex could be used to decode object identity from similar to 80 ms post stimulus onset, and activity in peri-frontal cortex could also be used to decode object identity from a later time (similar to 265 ms post stimulus onset). Low spatial frequency information related to object identity was present in the MEG signal at an earlier time than high spatial frequency information for peri-occipital cortex, but not for peri-frontal cortex. We additionally used Granger causality analysis to compare feedforward and feedback influences on representational content, and found evidence of both an early feedfoward flow and later feedback flow of information related to object identity. We discuss our findings in relation to existing theories of object processing and propose how the methods we use here could be used to address further questions of the neural substrates underlying object perception. (C) 2016 Elsevier Inc. All rights reserved.