Liu C H, Chaudhuri A
Department of Psychology, McGill University, Montreal, Quebec, Canada.
Perception. 1997;26(10):1289-96. doi: 10.1068/p261289.
The effects of photographic negatives on face recognition are often studied in two different ways--faces are learned and tested in photographic negatives (NN) or the contrast is reversed between learning and testing, i.e. they are learned in positives and tested in negatives (PN) or vice versa (NP). We have examined recognition performance for faces under these three conditions along with a control condition where faces were learned and tested in positives (PP). Using multi-tone face images, we found that the effect of photographic negatives was more pronounced in PN and NP than in NN. No differences were found between PN and NP or between NN and PP. When two-tone face images were used, recognition performance was worse in all conditions, except PP, when compared to the multi-tone counterparts. Our results show that contrast incongruency between learning and testing is the predominant factor affecting performance and that deficits in sensory coding or retention of negative face images are unlikely to be major factors. The advantage of multi-tone over two-tone negatives can be attributed to preserved facial information carried by the high-spatial-frequency components of the image.
摄影负片对面部识别的影响通常通过两种不同方式进行研究——在摄影负片中学习和测试面部（NN），或者在学习和测试之间反转对比度，即正片学习负片测试（PN），反之亦然（NP）。我们研究了这三种条件下以及一种对照条件（正片学习正片测试，PP）下面部的识别性能。使用多色调面部图像时，我们发现摄影负片在PN和NP条件下的影响比在NN条件下更明显。PN和NP之间以及NN和PP之间未发现差异。使用双色调面部图像时，与多色调对应图像相比，除PP条件外，所有条件下的识别性能均较差。我们的结果表明，学习和测试之间的对比度不一致是影响性能的主要因素，而感觉编码缺陷或负性面部图像的留存不太可能是主要因素。多色调负片相对于双色调负片的优势可归因于图像高空间频率成分所携带的保留面部信息。
