Maidment David W, Kang HiJee, Gill Emma C, Amitay Sygal
Medical Research Council Institute of Hearing Research, Nottingham, United Kingdom.
PLoS One. 2015 Mar 24;10(3):e0121953. doi: 10.1371/journal.pone.0121953. eCollection 2015.
Learning is considered to consist of two distinct phases-acquisition and consolidation. Acquisition can be disrupted when short periods of training on more than one task are interleaved, whereas consolidation can be disrupted when a second task is trained after the first has been initiated. Here we investigated the conditions governing the disruption to acquisition and consolidation during mixed-training regimens in which primary and secondary amplitude modulation tasks were either interleaved or presented consecutively. The secondary task differed from the primary task in either task-irrelevant (carrier frequency) or task-relevant (modulation rate) stimulus features while requiring the same perceptual judgment (amplitude modulation depth discrimination), or shared both irrelevant and relevant features but required a different judgment (amplitude modulation rate discrimination). Based on previous literature we predicted that acquisition would be disrupted by varying the task-relevant stimulus feature during training (stimulus interference), and that consolidation would be disrupted by varying the perceptual judgment required (task interference). We found that varying the task-relevant or -irrelevant stimulus features failed to disrupt acquisition but did disrupt consolidation, whereas mixing two tasks requiring a different perceptual judgment but sharing the same stimulus features disrupted both acquisition and consolidation. Thus, a distinction between acquisition and consolidation phases of perceptual learning cannot simply be attributed to (task-relevant) stimulus versus task interference. We propose instead that disruption occurs during acquisition when mixing two tasks requiring a perceptual judgment based on different cues, whereas consolidation is always disrupted regardless of whether different stimulus features or tasks are mixed. The current study not only provides a novel insight into the underlying mechanisms of perceptual learning, but also has practical implications for the optimal design and delivery of training programs that aim to remediate perceptual difficulties.
学习被认为由两个不同阶段组成——习得和巩固。当在多个任务上进行的短期训练相互交错时，习得过程可能会受到干扰；而当在第一个任务开始后再训练第二个任务时，巩固过程可能会受到干扰。在此，我们研究了在混合训练方案中影响习得和巩固过程受干扰的条件，其中主要和次要调幅任务要么相互交错呈现，要么连续呈现。次要任务在与任务无关的（载波频率）或与任务相关的（调制率）刺激特征方面与主要任务不同，同时需要相同的感知判断（调幅深度辨别），或者共享无关和相关特征，但需要不同的判断（调幅率辨别）。基于先前的文献，我们预测在训练期间改变与任务相关的刺激特征（刺激干扰）会干扰习得，而改变所需的感知判断（任务干扰）会干扰巩固。我们发现，改变与任务相关或无关的刺激特征未能干扰习得，但确实干扰了巩固，而混合两个需要不同感知判断但共享相同刺激特征的任务则干扰了习得和巩固。因此，感知学习的习得和巩固阶段之间的区别不能简单地归因于（与任务相关的）刺激与任务干扰。相反，我们提出，当混合两个基于不同线索进行感知判断的任务时，习得过程会受到干扰，而无论是否混合不同的刺激特征或任务，巩固过程总是会受到干扰。当前的研究不仅为感知学习的潜在机制提供了新的见解，而且对旨在纠正感知困难的训练计划的优化设计和实施具有实际意义。
