Liu Jiajuan, Lu Zhong-Lin, Dosher Barbara Anne
Laboratory of Brain Processes (LOBES), Neuroscience Graduate Program, Department of Biological Science, University of Southern California, Los Angeles, CA 90089-1061, United States.
Vision Res. 2012 May 15;61:15-24. doi: 10.1016/j.visres.2011.12.002. Epub 2011 Dec 29.
In this study, we investigated whether mixing easy and difficult trials can lead to learning in the difficult conditions. We hypothesized that while feedback is necessary for significant learning in training regimes consisting solely of low training accuracy trials, training mixtures with sufficient proportions of high accuracy training trials would lead to significant learning without feedback. Thirty-six subjects were divided into one experimental group in which trials with high training accuracy were mixed with those with low training accuracy and no feedback, and five control groups in which high and low accuracy training were mixed in the presence of feedback; high and high training accuracy were mixed or low and low training accuracy were mixed with and without feedback trials. Contrast threshold improved significantly in the low accuracy condition in the presence of high training accuracy trials (the high-low mixture group) in the absence of feedback, although no significant learning was found in the low accuracy condition in the group with the low-low mixture without feedback. Moreover, the magnitude of improvement in low accuracy trials without feedback in the high-low training mixture is comparable to that in the high accuracy training without feedback condition and those obtained in the presence of trial-by-trial external feedback. The results are both qualitatively and quantitatively consistent with the predictions of the Augmented Hebbian Re-Weighting model. We conclude that mixed training at high and low accuracy levels can lead to perceptual learning at low training accuracy levels without feedback.
在本研究中，我们调查了混合简单和困难试验是否会在困难条件下促成学习。我们假设，虽然在仅由低训练准确率试验组成的训练模式中，反馈对于显著学习是必要的，但具有足够比例高准确率训练试验的训练混合组将在无反馈的情况下促成显著学习。36名受试者被分为一个实验组，其中高训练准确率的试验与低训练准确率的试验混合且无反馈，以及五个对照组，其中高准确率和低准确率训练在有反馈的情况下混合；高准确率与高准确率训练混合，或低准确率与低准确率训练混合，有反馈试验和无反馈试验皆有。在无反馈的情况下，高训练准确率试验（高低混合组）存在时，低准确率条件下的对比阈值显著提高，尽管在无反馈的低低混合组的低准确率条件下未发现显著学习。此外，高低训练混合中无反馈的低准确率试验的改善幅度与无反馈的高准确率训练条件下以及逐次试验外部反馈存在时所获得的改善幅度相当。结果在定性和定量上均与增强赫布重加权模型的预测一致。我们得出结论，高低准确率水平的混合训练可在无反馈的情况下促成低训练准确率水平的知觉学习。
