Perceptual learning in contrast discrimination: The effect of contrast uncertainty
Perceptual learning in contrast discrimination: The effect of contrast uncertainty
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DOI：
10.1167/4.12.2
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发表时间：
2004-01-01
影响因子：
1.8
通讯作者：
Sagi, D
中科院分区：
文献类型：
--
作者：
Adini, Y;Wilkonsky, A;Sagi, D
知觉任务的表现随着重复（知觉学习）而提高，最终达到饱和水平。通常，当研究感知学习效果时，刺激参数在整个训练过程中以及训练前和训练后测试期间保持恒定。在这里，我们调查是否通过重复学习转移到测试条件下，在训练后的会议期间，实践的刺激随机交错。我们研究了对比辨别任务的练习效果，采用了许多训练方法：（i）使用单个固定基座（基础对比）进行练习，（ii）使用多个基座进行练习，（iii）使用包括空间背景的多个基座进行练习。训练前和训练后的测试进行了随机的基础对比试验，对比的不确定性的条件下。结果表明，学习发生了固定基座方法（i）和上下文方法（iii），但只有后者幸存的不确定性测试。此外，我们能够在对比度辨别中识别出一个非常快速的学习阶段，从而提高了不确定性下的性能。我们认为，学习任务，不通过不确定性测试涉及修改决策策略，需要确切的知识的刺激。
Performance in perceptual tasks improves with repetition (perceptual learning), eventually reaching a saturation level. Typically, when perceptual learning effects are studied, stimulus parameters are kept constant throughout the training and during the pre- and post-training tests. Here we investigate whether learning by repetition transfers to testing conditions in which the practiced stimuli are randomly interleaved during the post-training session. We studied practice effects with a contrast discrimination task, employing a number of training methods: (i) practice with a single, fixed pedestal (base-contrast), (ii) practice with several pedestals, and (iii) practice with several pedestals that included a spatial context. Pre- and post-training tests were carried out with the base contrast randomized across trials, under conditions of contrast uncertainty. The results showed that learning had taken place with the fixed pedestal method (i) and with the context method (iii), but only the latter survived the uncertainty test. In addition, we were able to identify a very fast learning phase in contrast discrimination that improved performance under uncertainty. We contend that learned tasks that do not pass the uncertainty test involve modification of decision strategies that require exact knowledge of the stimulus.