Centre for Speech, Language and the Brain, Department of Experimental Psychology, University of Cambridge, United Kingdom.
J Cogn Neurosci. 2011 Aug;23(8):1887-99. doi: 10.1162/jocn.2010.21544. Epub 2010 Jul 9.
Research on the spatio-temporal dynamics of visual object recognition suggests a recurrent, interactive model whereby an initial feedforward sweep through the ventral stream to prefrontal cortex is followed by recurrent interactions. However, critical questions remain regarding the factors that mediate the degree of recurrent interactions necessary for meaningful object recognition. The novel prediction we test here is that recurrent interactivity is driven by increasing semantic integration demands as defined by the complexity of semantic information required by the task and driven by the stimuli. To test this prediction, we recorded magnetoencephalography data while participants named living and nonliving objects during two naming tasks. We found that the spatio-temporal dynamics of neural activity were modulated by the level of semantic integration required. Specifically, source reconstructed time courses and phase synchronization measures showed increased recurrent interactions as a function of semantic integration demands. These findings demonstrate that the cortical dynamics of object processing are modulated by the complexity of semantic information required from the visual input.
视觉对象识别的时空动态研究表明，存在一种递归、交互的模型，即从前腹侧流到前额叶皮层的初始前馈扫描之后是递归交互。然而，对于调节递归交互程度的因素，以及这些因素对于有意义的对象识别的必要性，仍存在一些关键问题。我们在这里测试的新预测是，递归交互性是由任务所需的语义信息的复杂性所定义的语义整合需求的增加驱动的，并且是由刺激驱动的。为了验证这一预测，我们在参与者进行两个命名任务时记录了脑磁图数据，让他们说出生物和非生物物体的名称。我们发现，神经活动的时空动态受到所需语义整合水平的调节。具体来说，源重建时间过程和相位同步测量显示，随着语义整合需求的增加，递归交互作用也在增加。这些发现表明，视觉输入所需的语义信息的复杂性调节了对象处理的皮层动力学。
