Tanaka Hideaki
1 Department of Psychology, Faculty of Psychology, Otemon Gakuin University, Japan.
Percept Mot Skills. 2018 Dec;125(6):1011-1028. doi: 10.1177/0031512518803202.
This study investigated the relationship between length of hair in facial stimuli and latency and amplitude of the P1 and N170 components of event-related potentials during facial perception. Electroencephalography was recorded from 21 Japanese participants (four men, 17 women) who were shown pictures of faces with one of three lengths of hair: long, medium length, or short. In addition, we used both fixed-size and variable-size blocks. In fixed-size blocks, the three types of stimuli were matched to have the same overall size; in variable-size blocks, long hair stimuli were the biggest, medium length hair stimuli were medium sized, and short hair stimuli were the smallest. We analyzed P1 latency and amplitude using two-way (6 × 2) repeated-measures analysis of variance over length of hair and electrode; N170 latency and amplitude were analyzed using three-way (6 × 2 × 2) repeated-measures analysis of variance over length of hair, hemisphere, and electrode. The latency of P1 to faces with short hair in variable-size blocks was significantly longer than that to the other five stimulus types ( p < .01 for four of the other types; p = .083 for medium length hair in variable-size blocks). The latency of N170 to faces with long hair in variable-size blocks was significantly shorter than that to faces with medium length hair and short hair in variable-size blocks ( p = .026 and p = .086, respectively). These results indicate that length of hair influenced P1 and N170 latency, supporting the notion that length of hair is a significant external facial feature. Because long hair attracted participants' attention, there was early perceptual processing of this feature. In contrast, because short hair did not attract attention, perceptual processing of this feature was late.
本研究调查了面部刺激中头发长度与面部感知过程中事件相关电位的P1和N170成分的潜伏期及波幅之间的关系。对21名日本参与者（4名男性，17名女性）进行脑电图记录，向他们展示具有三种头发长度之一的面部图片：长发、中等长度或短发。此外，我们使用了固定大小和可变大小的图片组。在固定大小的图片组中，三种类型的刺激匹配为具有相同的整体大小；在可变大小的图片组中，长发刺激最大，中等长度头发刺激为中等大小，短发刺激最小。我们使用双向（6×2）重复测量方差分析对头发长度和电极进行分析，以研究P1潜伏期和波幅；使用三向（6×2×2）重复测量方差分析对头发长度、半球和电极进行分析，以研究N170潜伏期和波幅。在可变大小的图片组中，P1对短发面部的潜伏期显著长于对其他五种刺激类型的潜伏期（其他四种类型p <.01；可变大小图片组中中等长度头发的p = 0.083）。在可变大小的图片组中，N170对长发面部的潜伏期显著短于对中等长度头发和短发面部的潜伏期（分别为p = 0.026和p = 0.086）。这些结果表明，头发长度影响了P1和N170的潜伏期，支持了头发长度是一个重要的面部外部特征的观点。因为长发吸引了参与者的注意力，所以对这一特征有早期的感知处理。相比之下，因为短发没有吸引注意力，所以对这一特征的感知处理较晚。
