Lorenzino Martina, Caudek Corrado
Università degli Studi di Firenze, Department of Neurosciences, Psychology, Drug Research, and Child Health (NEUROFARBA), Via di San Salvi 12, Complesso di San Salvi, Padiglione 26, 50135 Firenze (FI), Italy.
Vision Res. 2015 Mar;108:56-66. doi: 10.1016/j.visres.2015.01.007. Epub 2015 Jan 30.
We understand poorly how the ability to discriminate faces from one another is shaped by visual experience. The purpose of the present study is to determine whether face discrimination learning can be facilitated by facial emotions. To answer this question, we used a task-irrelevant perceptual learning paradigm because it closely mimics the learning processes that, in daily life, occur without a conscious intention to learn and without an attentional focus on specific facial features. We measured face discrimination thresholds before and after training. During the training phase (4 days), participants performed a contrast discrimination task on face images. They were not informed that we introduced (task-irrelevant) subtle variations in the face images from trial to trial. For the Identity group, the task-irrelevant features were variations along a morphing continuum of facial identity. For the Emotion group, the task-irrelevant features were variations along an emotional expression morphing continuum. The Control group did not undergo contrast discrimination learning and only performed the pre-training and post-training tests, with the same temporal gap between them as the other two groups. Results indicate that face discrimination improved, but only for the Emotion group. Participants in the Emotion group, moreover, showed face discrimination improvements also for stimulus variations along the facial identity dimension, even if these (task-irrelevant) stimulus features had not been presented during training. The present results highlight the importance of emotions for face discrimination learning.
我们对视觉经验如何塑造区分不同面孔的能力了解甚少。本研究的目的是确定面部情绪是否能促进面孔辨别学习。为了回答这个问题，我们使用了一种与任务无关的知觉学习范式，因为它紧密模仿了在日常生活中发生的学习过程，即在没有有意识学习意图且没有对特定面部特征进行注意力聚焦的情况下发生的学习过程。我们在训练前后测量了面孔辨别阈值。在训练阶段（4天），参与者对面部图像执行对比度辨别任务。他们未被告知我们在每次试验中对面部图像引入了（与任务无关的）细微变化。对于身份组，与任务无关的特征是沿着面部身份的变形连续体的变化。对于情绪组，与任务无关的特征是沿着情感表达变形连续体的变化。对照组未进行对比度辨别学习，只进行了训练前和训练后的测试，两组之间的时间间隔与其他两组相同。结果表明，面孔辨别能力有所提高，但仅在情绪组中出现。此外，情绪组的参与者在面部身份维度上的刺激变化方面也表现出面孔辨别能力的提高，即使这些（与任务无关的）刺激特征在训练期间未被呈现。目前的结果突出了情绪在面孔辨别学习中的重要性。
