Knight Rebecca, Piette Caitlin E, Page Hector, Walters Daniel, Marozzi Elizabeth, Nardini Marko, Stringer Simon, Jeffery Kathryn J
Division of Psychology and Language Sciences, Department of Cognitive, Perceptual and Brain Sciences, Institute of Behavioural Neuroscience, University College London, , 26 Bedford Way, London WC1H 0AP, UK.
Philos Trans R Soc Lond B Biol Sci. 2013 Dec 23;369(1635):20120512. doi: 10.1098/rstb.2012.0512. Print 2014 Feb 5.
How the brain combines information from different sensory modalities and of differing reliability is an important and still-unanswered question. Using the head direction (HD) system as a model, we explored the resolution of conflicts between landmarks and background cues. Sensory cue integration models predict averaging of the two cues, whereas attractor models predict capture of the signal by the dominant cue. We found that a visual landmark mostly captured the HD signal at low conflicts: however, there was an increasing propensity for the cells to integrate the cues thereafter. A large conflict presented to naive rats resulted in greater visual cue capture (less integration) than in experienced rats, revealing an effect of experience. We propose that weighted cue integration in HD cells arises from dynamic plasticity of the feed-forward inputs to the network, causing within-trial spatial redistribution of the visual inputs onto the ring. This suggests that an attractor network can implement decision processes about cue reliability using simple architecture and learning rules, thus providing a potential neural substrate for weighted cue integration.
大脑如何整合来自不同感觉模态且可靠性不同的信息是一个重要且尚未得到解答的问题。我们以头部方向（HD）系统为模型，探究了地标与背景线索之间冲突的解决方式。感觉线索整合模型预测两种线索会进行平均，而吸引子模型预测主导线索会捕获信号。我们发现，在冲突较小时，视觉地标大多会捕获HD信号；然而，此后细胞整合线索的倾向会增加。与经验丰富的大鼠相比，向未经训练的大鼠呈现较大冲突时会导致更多的视觉线索捕获（更少的整合），这揭示了经验的影响。我们提出，HD细胞中的加权线索整合源于网络前馈输入的动态可塑性，导致视觉输入在试验过程中在环上进行空间重新分布。这表明，吸引子网络可以使用简单的架构和学习规则来执行关于线索可靠性的决策过程，从而为加权线索整合提供潜在的神经基础。
