Civile Ciro, Obhi Sukhvinder S, McLaren I P L
School of Psychology, College of Life and Environmental Sciences, University of Exeter, UK.
Department of Psychology, Neuroscience & Behaviour (PNB), McMaster University, Canada.
Vision Res. 2019 Apr;157:84-88. doi: 10.1016/j.visres.2018.02.010. Epub 2018 Apr 3.
Perceptual learning of the type we consider here is a consequence of experience with a class of stimuli. It amounts to an enhanced ability to discriminate between stimuli. We argue that it contributes to the ability to distinguish between faces and recognize individuals, and in particular contributes to the face inversion effect (better recognition performance for upright vs inverted faces). Previously, we have shown that experience with a prototype defined category of checkerboards leads to perceptual learning, that this produces an inversion effect, and that this effect can be disrupted by Anodal tDCS to Fp3 during pre-exposure. If we can demonstrate that the same tDCS manipulation also disrupts the inversion effect for faces, then this will strengthen the claim that perceptual learning contributes to that effect. The important question, then, is whether this tDCS procedure would significantly reduce the inversion effect for faces; stimuli that we have lifelong expertise with and for which perceptual learning has already occurred. Consequently, in the experiment reported here we investigated the effects of anodal tDCS at Fp3 during an old/new recognition task for upright and inverted faces. Our results show that stimulation significantly reduced the face inversion effect compared to controls. The effect was one of reducing recognition performance for upright faces. This result is the first to show that tDCS affects perceptual learning that has already occurred, disrupting individuals' ability to recognize upright faces. It provides further support for our account of perceptual learning and its role as a key factor in face recognition.
我们在此所考虑的这种类型的知觉学习是对一类刺激物的体验所产生的结果。它等同于辨别刺激物能力的增强。我们认为，它有助于区分面孔和识别个体的能力，特别是有助于面孔倒置效应（正立面孔与倒置面孔相比，识别表现更佳）。此前，我们已经表明，对棋盘格的原型定义类别进行体验会导致知觉学习，这会产生倒置效应，并且在预暴露期间对额极区Fp3进行阳极性经颅直流电刺激（Anodal tDCS）会破坏这种效应。如果我们能够证明相同的经颅直流电刺激操作也会破坏面孔的倒置效应，那么这将强化知觉学习促成该效应这一观点。那么，重要的问题在于，这种经颅直流电刺激程序是否会显著降低面孔的倒置效应；面孔是我们拥有毕生专业知识且已经发生了知觉学习的刺激物。因此，在本文所报告的实验中，我们研究了在正立和倒置面孔的旧/新识别任务期间，对额极区Fp3施加阳极性经颅直流电刺激的效果。我们的结果表明，与对照组相比，刺激显著降低了面孔倒置效应。该效应表现为降低了对正立面孔的识别表现。这一结果首次表明，经颅直流电刺激会影响已经发生的知觉学习，破坏个体识别正立面孔的能力。它为我们关于知觉学习及其作为人脸识别关键因素的作用的观点提供了进一步的支持。
