Subcortical Plasticity Following Perceptual Learning in a Pitch Discrimination Task
Subcortical Plasticity Following Perceptual Learning in a Pitch Discrimination Task
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DOI：
10.1007/s10162-010-0236-1
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发表时间：
2011-02-01
影响因子：
2.4
通讯作者：
Plack, Christopher J.
中科院分区：
文献类型：
--
作者：
Carcagno, Samuele;Plack, Christopher J.
练习可以显著提高对听觉刺激的辨别能力。在这项研究中，我们研究了听觉诱发电位的皮层下成分频率跟随反应（FFR）在一段时间的音高辨别训练后的变化。27名成年听众接受了为期10小时的音高辨别训练，使用了三种不同的复杂音调刺激。一个是静态音高轮廓，一个是上升音高轮廓，一个是下降音高轮廓。在训练前和训练后，对这些参与者以及未训练的对照组（n=12）进行了音高辨别和ffr的行为测量。与对照组相比，受过训练的参与者在所有三种训练刺激下的音高辨别能力都有显著提高。这些改善部分是针对与训练刺激具有相同音调调制（动态与静态）和相同音调轨迹（上升与下降）的刺激。此外，与对照组相比，训练参与者的FFR神经相位锁定在静态和上升轮廓上的稳健性显著增加，而在下降轮廓上则没有增加。FFR强度的变化部分特定于具有相同音高调制的刺激（动态与静态）。然而，FFR强度的变化并不特定于与训练刺激具有相同俯仰轨迹（上升或下降）的刺激。这些发现表明，即使是成熟听觉系统中相对低级的过程也会受到经验相关变化的影响。
Practice can lead to dramatic improvements in the discrimination of auditory stimuli. In this study, we investigated changes of the frequency-following response (FFR), a subcortical component of the auditory evoked potentials, after a period of pitch discrimination training. Twenty-seven adult listeners were trained for 10 h on a pitch discrimination task using one of three different complex tone stimuli. One had a static pitch contour, one had a rising pitch contour, and one had a falling pitch contour. Behavioral measures of pitch discrimination and FFRs for all the stimuli were measured before and after the training phase for these participants, as well as for an untrained control group (n=12). Trained participants showed significant improvements in pitch discrimination compared to the control group for all three trained stimuli. These improvements were partly specific for stimuli with the same pitch modulation (dynamic vs. static) and with the same pitch trajectory (rising vs. falling) as the trained stimulus. Also, the robustness of FFR neural phase locking to the sound envelope increased significantly more in trained participants compared to the control group for the static and rising contour, but not for the falling contour. Changes in FFR strength were partly specific for stimuli with the same pitch modulation (dynamic vs. static) of the trained stimulus. Changes in FFR strength, however, were not specific for stimuli with the same pitch trajectory (rising vs. falling) as the trained stimulus. These findings indicate that even relatively low-level processes in the mature auditory system are subject to experience-related change.