Asher Jordi M, Romei Vincenzo, Hibbard Paul B
Department of Psychology, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, UK.
Dipartimento di Psicologia and Centro Studi e Ricerche in Neuroscienze Cognitive, Campus di Cesena, Università di Bologna, 47521 Cesena, Italy.
Vision (Basel). 2019 Sep 2;3(3):44. doi: 10.3390/vision3030044.
Perceptual learning is typically highly specific to the stimuli and task used during training. However, recently, it has been shown that training on global motion can transfer to untrained tasks, reflecting the generalising properties of mechanisms at this level of processing. We investigated (i) if feedback was required for learning in a motion coherence task, (ii) the transfer across the spatial frequency of training on a global motion coherence task and (iii) the transfer of this training to a measure of contrast sensitivity. For our first experiment, two groups, with and without feedback, trained for ten days on a broadband motion coherence task. Results indicated that feedback was a requirement for robust learning. For the second experiment, training consisted of five days of direction discrimination using one of three motion coherence stimuli (where individual elements were comprised of either broadband Gaussian blobs or low- or high-frequency random-dot ), with trial-by-trial auditory feedback. A pre- and post-training assessment was conducted for each of the three types of global motion coherence conditions and high and low spatial frequency contrast sensitivity (both without feedback). Our training paradigm was successful at eliciting improvement in the trained tasks over the five days. Post-training assessments found evidence of transfer for the motion coherence task exclusively for the group trained on low spatial frequency elements. For the contrast sensitivity tasks, improved performance was observed for low- and high-frequency stimuli, following motion coherence training with broadband stimuli, and for low-frequency stimuli, following low-frequency training. Our findings are consistent with perceptual learning, which depends on the global stage of motion processing in higher cortical areas, which is broadly tuned for spatial frequency, with a preference for low frequencies.
知觉学习通常对训练期间使用的刺激和任务具有高度特异性。然而，最近有研究表明，全局运动训练可以迁移到未训练的任务中，这反映了该处理水平机制的泛化特性。我们研究了：（i）在运动连贯性任务中学习是否需要反馈；（ii）全局运动连贯性任务训练在空间频率上的迁移情况；（iii）这种训练对对比度敏感度测量的迁移情况。在我们的第一个实验中，两组被试，一组有反馈，一组无反馈，在宽带运动连贯性任务上训练了十天。结果表明，反馈是稳健学习的必要条件。在第二个实验中，训练包括使用三种运动连贯性刺激之一进行为期五天的方向辨别（其中单个元素由宽带高斯斑点或低频或高频随机点组成），并伴有逐次试验的听觉反馈。对三种类型的全局运动连贯性条件以及高、低空间频率对比度敏感度（均无反馈）分别进行了训练前和训练后的评估。我们的训练范式成功地在五天内使训练任务得到了改善。训练后评估发现，仅在低空间频率元素上训练的组在运动连贯性任务中有迁移证据。对于对比度敏感度任务，在使用宽带刺激进行运动连贯性训练后，低频和高频刺激的性能有所提高；在进行低频训练后，低频刺激的性能有所提高。我们的研究结果与知觉学习一致，知觉学习依赖于更高皮层区域中运动处理的全局阶段，该阶段对空间频率进行广泛调谐，且偏好低频。
