Flexible Categorization of Relative Stimulus Strength by the Optic Tectum
Flexible Categorization of Relative Stimulus Strength by the Optic Tectum
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DOI：
10.1523/jneurosci.5425-10.2011
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发表时间：
2011-05-25
影响因子：
5.3
通讯作者：
Knudsen, Eric I.
中科院分区：
文献类型：
--
作者：
Mysore, Shreesh P.;Knudsen, Eric I.
分类是大脑将连续变化的刺激分离成离散组的过程。我们报告了猫头鹰视觉顶盖（OT）的神经群活动模式根据它们的相对强度将刺激分类为“最强”和“其他”。类别边界自适应地移动以跟踪最强刺激的绝对强度的变化。这种群体范围的分类是由一小部分神经元的反应介导的。我们的数据构成了基于相对刺激强度或显著性的神经网络对刺激进行明确分类的第一个直接演示。由总体编码分类的发现放宽了对下游解码器属性的限制，这些解码器可能会读出最强刺激的位置。这些结果表明，OT中的集成神经编码可以介导自下而上的凝视和注意刺激选择，这是一种类别边界经常在数百毫秒内发生变化的刺激分类形式。
Categorization is the process by which the brain segregates continuously variable stimuli into discrete groups. We report that patterns of neural population activity in the owl optic tectum (OT) categorize stimuli based on their relative strengths into "strongest" versus "other." The category boundary shifts adaptively to track changes in the absolute strength of the strongest stimulus. This population-wide categorization is mediated by the responses of a small subset of neurons. Our data constitute the first direct demonstration of explicit categorization of stimuli by a neural network based on relative stimulus strength or salience. The finding of categorization by the population code relaxes constraints on the properties of downstream decoders that might read out the location of the strongest stimulus. These results indicate that the ensemble neural code in the OT could mediate bottom-up stimulus selection for gaze and attention, a form of stimulus categorization in which the category boundary often shifts within hundreds of milliseconds.