Perceptual learning reflects external noise filtering and internal noise reduction through channel reweighting
Perceptual learning reflects external noise filtering and internal noise reduction through channel reweighting
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DOI：
10.1073/pnas.95.23.13988
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发表时间：
1998-11-10
影响因子：
11.1
通讯作者：
Lu, ZL
中科院分区：
文献类型：
--
作者：
Dosher, BA;Lu, ZL
为了研究成人视觉系统的可塑性本质，在系统地改变外部(环境)噪声的情况下，在外围方位辨别任务中测量知觉学习。在所有级别的外部噪声下进行训练后，达到阈值所需的信号对比度降低了一倍或两倍或更多。这一新范式揭示的强大的数量规律性排除了乘性内部噪声的变化、换能器非线性的变化以及简单的注意权衡。相反，规则将行为水平上的知觉学习机制指定为外部噪音排除和通过相加的内部噪音降低来增强刺激的组合。这些发现还限制了知觉学习的神经结构。基本视觉通道和判断之间的权重的可塑性足以解释知觉学习，而不需要重新调整视觉机制。
To investigate the nature of plasticity in the adult visual system, perceptual learning was measured in a peripheral orientation discrimination task with systematically varying amounts of external (environmental) noise. The signal contrasts required to achieve threshold were reduced by a factor or two or more after training at all levels of external noise. The strong quantitative regularities revealed by this novel paradigm ruled out changes in multiplicative internal noise, changes in transducer nonlinearites, and simple attentional tradeoffs. Instead, the regularities specify the mechanisms of perceptual learning at the behavioral level as a combination of external noise exclusion and stimulus enhancement via additive internal noise reduction. The findings also constrain the neural architecture of perceptual learning. Plasticity in the weights between basic visual channels and decision is sufficient to account for perceptual learning without requiring the retuning of visual mechanisms.