Neural Architecture for Feature Binding in Visual Working Memory.
Neural Architecture for Feature Binding in Visual Working Memory.
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DOI：
10.1523/jneurosci.3493-16.2017
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发表时间：
2017-04-05
期刊：
影响因子：
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通讯作者：
Bays PM
中科院分区：
文献类型：
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作者：
Schneegans S;Bays PM
绑定是指将不同的功能组合到对象中的操作。我们提出了一个神经结构的特征绑定在视觉工作记忆中，采用群体的神经元与连接反应。我们使用线索回忆任务测试了这个模型，在这个任务中，受试者必须记住由简单视觉特征（颜色、方向和位置）组成的物体阵列。在短暂的延迟之后，一个项目的一个特征被给出作为提示，观察者必须在连续的量表上报告提示项目的一个或两个其他特征。此任务中的绑定失败与交换错误相关，其中观察者报告的项目与提示所指示的项目不同。我们观察到两个项目互换的概率与项目在线索特征维度上的相似性密切相关，并且发现空间报告和非空间报告中发生的互换错误之间存在密切相关。神经模型解释了交换错误和响应变异性作为解码噪声神经活动的结果，并且可以定量详细地解释行为结果。然后，我们使用该模型来比较绑定非空间特征的替代机制。我们发现行为结果完全符合一个模型，其中非空间特征仅通过其共享位置绑定，没有迹象表明颜色和方向之间的直接绑定。这些结果为位置在特征绑定中的特殊作用提供了证据，该模型解释了这种特殊作用如何在神经系统中实现。特征绑定的问题对于理解工作记忆的机制至关重要。我们如何不仅记住我们看到了一个红色和一个圆形的物体，而且记住这些特征属于一个单一的物体，而不是我们环境中的不同物体？在这里，我们提出了证据的神经机制的功能绑定在工作记忆中，基于编码的视觉信息的神经元，响应连接的功能。我们发现了明确的证据，表明非空间特征是通过空间绑定的：我们直接记住颜色或方向出现的位置，但我们只能通过它们的共享位置间接地记住哪种颜色属于哪种方向。
Binding refers to the operation that groups different features together into objects. We propose a neural architecture for feature binding in visual working memory that employs populations of neurons with conjunction responses. We tested this model using cued recall tasks, in which subjects had to memorize object arrays composed of simple visual features (color, orientation, and location). After a brief delay, one feature of one item was given as a cue, and the observer had to report, on a continuous scale, one or two other features of the cued item. Binding failure in this task is associated with swap errors, in which observers report an item other than the one indicated by the cue. We observed that the probability of swapping two items strongly correlated with the items' similarity in the cue feature dimension, and found a strong correlation between swap errors occurring in spatial and nonspatial report. The neural model explains both swap errors and response variability as results of decoding noisy neural activity, and can account for the behavioral results in quantitative detail. We then used the model to compare alternative mechanisms for binding nonspatial features. We found the behavioral results fully consistent with a model in which nonspatial features are bound exclusively via their shared location, with no indication of direct binding between color and orientation. These results provide evidence for a special role of location in feature binding, and the model explains how this special role could be realized in the neural system. SIGNIFICANCE STATEMENT The problem of feature binding is of central importance in understanding the mechanisms of working memory. How do we remember not only that we saw a red and a round object, but that these features belong together to a single object rather than to different objects in our environment? Here we present evidence for a neural mechanism for feature binding in working memory, based on encoding of visual information by neurons that respond to the conjunction of features. We find clear evidence that nonspatial features are bound via space: we memorize directly where a color or an orientation appeared, but we memorize which color belonged with which orientation only indirectly by virtue of their shared location.