Rummens Koen, Sayim Bilge
University of Bern, Institute of Psychology, Switzerland.
University of Bern, Institute of Psychology, Switzerland; Univ. Lille, CNRS, UMR 9193 - SCALab - Sciences Cognitives et Sciences Affectives, F-59000 Lille, France.
Vision Res. 2019 Aug;161:25-35. doi: 10.1016/j.visres.2019.05.006. Epub 2019 Jun 13.
Peripheral word recognition is impaired by crowding, the harmful influence of surrounding objects (flankers) on target identification. Crowding is usually weaker when the target and the flankers differ (for example in color). Here, we investigated whether reducing crowding at syllable boundaries improved peripheral word recognition. In Experiment 1, a target letter was flanked by single letters to the left and right and presented at 8° in the lower visual field. Target and flankers were either the same or different in regard to contrast polarity, color, luminance, and combined color/luminance. Crowding was reduced when the target differed from the flankers in contrast polarity, but not in any of the other conditions. Using the same color and luminance values as in Experiment 1, we measured recognition performance (speed and accuracy) for uniform (e.g., all letters black), congruent (e.g., alternating black and white syllables), and incongruent (e.g., alternating black and white non-syllables) words in Experiment 2. Participants verbally reported the target word, briefly displayed at 8° in the lower visual field. Congruent and incongruent words were recognized slower compared to uniform words in the opposite contrast polarity condition, but not in the other conditions. Our results show that the same feature contrast between the target and the flankers that yielded reduced crowding, deteriorated peripheral word recognition when applied to syllables and non-syllabic word parts. We suggest that a potential advantage of reduced crowding at syllable boundaries in word recognition is counteracted by the disruption of word uniformity.
外周词识别会受到拥挤现象的损害,即周围物体(侧翼刺激)对目标识别的有害影响。当目标与侧翼刺激不同(例如颜色不同)时,拥挤通常会减弱。在此,我们研究了减少音节边界处的拥挤是否能改善外周词识别。在实验1中,一个目标字母的左右两侧各有一个单个字母作为侧翼刺激,并呈现于下视野8°处。目标与侧翼刺激在对比度极性、颜色、亮度以及颜色/亮度组合方面要么相同,要么不同。当目标与侧翼刺激在对比度极性上不同时,拥挤现象会减少,但在其他任何条件下均不会减少。在实验2中,我们使用与实验1相同的颜色和亮度值,测量了均匀(例如所有字母均为黑色)、一致(例如黑白音节交替)和不一致(例如黑白非音节交替)单词的识别性能(速度和准确性)。参与者口头报告短暂呈现于下视野8°处的目标单词。在相反的对比度极性条件下,与均匀单词相比,一致和不一致单词的识别速度较慢,但在其他条件下并非如此。我们的结果表明,目标与侧翼刺激之间相同的特征对比度在减少拥挤的同时,当应用于音节和非音节单词部分时,会降低外周词识别能力。我们认为,在单词识别中音节边界处拥挤减少的潜在优势会被单词均匀性的破坏所抵消。