Janssen Christian P, Verghese Preeti
The Smith-Kettlewell Eye Research Institute, San Francisco, CA, USADepartment of Experimental Psychology and Helmholtz Institute, Utrecht University, Utrecht, the
The Smith-Kettlewell Eye Research Institute, San Francisco, CA,
J Vis. 2016 Dec 1;16(15):29. doi: 10.1167/16.15.29.
We report a method to train individuals with central field loss due to macular degeneration to improve the efficiency of visual search. Our method requires participants to make a same/different judgment on two simple silhouettes. One silhouette is presented in an area that falls within the binocular scotoma while they are fixating the center of the screen with their preferred retinal locus (PRL); the other silhouette is presented diametrically opposite within the intact visual field. Over the course of 480 trials (approximately 6 hr), we gradually reduced the amount of time that participants have to make a saccade and judge the similarity of stimuli. This requires that they direct their PRL first toward the stimulus that is initially hidden behind the scotoma. Results from nine participants show that all participants could complete the task faster with training without sacrificing accuracy on the same/different judgment task. Although a majority of participants were able to direct their PRL toward the initially hidden stimulus, the ability to do so varied between participants. Specifically, six of nine participants made faster saccades with training. A smaller set (four of nine) made accurate saccades inside or close to the target area and retained this strategy 2 to 3 months after training. Subjective reports suggest that training increased awareness of the scotoma location for some individuals. However, training did not transfer to a different visual search task. Nevertheless, our study suggests that increasing scotoma awareness and training participants to look toward their scotoma may help them acquire missing information.
我们报告了一种训练因黄斑变性而出现中心视野缺损的个体提高视觉搜索效率的方法。我们的方法要求参与者对两个简单的轮廓做出相同/不同的判断。当他们用优势视网膜位点（PRL）注视屏幕中心时，一个轮廓呈现在双眼暗点范围内的区域；另一个轮廓则呈现在完整视野中与之相对的位置。在480次试验（约6小时）过程中，我们逐渐减少参与者进行扫视并判断刺激相似性所需的时间。这要求他们首先将PRL指向最初隐藏在暗点后面的刺激。九名参与者的结果表明，所有参与者在经过训练后都能更快地完成任务，同时在相同/不同判断任务上不牺牲准确性。虽然大多数参与者能够将他们的PRL指向最初隐藏的刺激，但参与者之间这样做的能力有所不同。具体而言，九名参与者中有六名在训练后扫视速度更快。一小部分（九名中的四名）能够在目标区域内或附近做出准确的扫视，并在训练后2至3个月保持这种策略。主观报告表明，训练提高了一些个体对暗点位置的意识。然而，训练并没有迁移到不同的视觉搜索任务中。尽管如此，我们的研究表明，提高对暗点的意识并训练参与者看向他们的暗点可能有助于他们获取缺失的信息。
