Loschky Lester C, Ringer Ryan V, Johnson Aaron P, Larson Adam M, Neider Mark, Kramer Arthur F
Department of Psychological Sciences, Kansas State University, Manhattan, KS, USA.
Department of Psychology, Concordia University, Montreal, Quebec, Canada.
Vis cogn. 2014 Mar;22(3):522-547. doi: 10.1080/13506285.2014.884203. Epub 2014 Mar 14.
Blur detection is affected by retinal eccentricity, but is it also affected by attentional resources? Research showing effects of selective attention on acuity and contrast sensitivity suggests that allocating attention should increase blur detection. However, research showing that blur affects selection of saccade targets suggests that blur detection may be pre-attentive. To investigate this question, we carried out experiments in which viewers detected blur in real-world scenes under varying levels of cognitive load manipulated by the -back task. We used adaptive threshold estimation to measure blur detection thresholds at 0°, 3°, 6°, and 9° eccentricity. Participants carried out blur detection as a single task, a single task with to-be-ignored letters, or an N-back task with four levels of cognitive load (0, 1, 2, or 3-back). In Experiment 1, blur was presented gaze-contingently for occasional single eye fixations while participants viewed scenes in preparation for an easy picture recognition memory task, and the -back stimuli were presented auditorily. The results for three participants showed a large effect of retinal eccentricity on blur thresholds, significant effects of -back level on -back performance, scene recognition memory, and gaze dispersion, but no effect of -back level on blur thresholds. In Experiment 2, we replicated Experiment 1 but presented the images tachistoscopically for 200 ms (half with, half without blur), to determine whether gaze-contingent blur presentation in Experiment 1 had produced attentional capture by blur onset during a fixation, thus eliminating any effect of cognitive load on blur detection. The results with three new participants replicated those of Experiment 1, indicating that the use of gaze-contingent blur presentation could not explain the lack of effect of cognitive load on blur detection. Thus, apparently blur detection in real-world scene images is unaffected by attentional resources, as manipulated by the cognitive load produced by the -back task.
模糊检测受视网膜离心率影响，但它也受注意力资源影响吗？显示选择性注意对视敏度和对比敏感度有影响的研究表明，分配注意力应能提高模糊检测能力。然而，显示模糊会影响扫视目标选择的研究表明，模糊检测可能是前注意的。为了探究这个问题，我们进行了实验，让观看者在由n-back任务操纵的不同认知负荷水平下检测现实场景中的模糊。我们使用自适应阈值估计来测量在0°、3°、6°和9°离心率下的模糊检测阈值。参与者将模糊检测作为单一任务、带有要忽略字母的单一任务或具有四个认知负荷水平（0、1、2或3-back）的n-back任务来进行。在实验1中，当参与者观看场景以准备进行简单的图片识别记忆任务时，模糊以注视点相关的方式偶尔呈现给单眼注视，并且n-back刺激通过听觉呈现。三名参与者的结果显示视网膜离心率对模糊阈值有很大影响，n-back水平对n-back表现、场景识别记忆和注视分散有显著影响，但n-back水平对模糊阈值没有影响。在实验2中，我们重复了实验1，但以200毫秒的速示器呈现图像（一半有模糊，一半没有模糊），以确定实验1中注视点相关的模糊呈现是否在注视期间因模糊开始而产生了注意力捕获，从而消除了认知负荷对模糊检测的任何影响。三名新参与者的结果重复了实验1的结果，表明使用注视点相关的模糊呈现无法解释认知负荷对模糊检测缺乏影响的原因。因此，显然现实场景图像中的模糊检测不受由n-back任务产生的认知负荷所操纵的注意力资源的影响。
