Department of Psychology, Vision Research Center, and Center for Cognitive and Integrative Neuroscience, Vanderbilt University, PMB 407817, 2301 Vanderbilt Place, Nashville, TN 37240-7817, USA.
Mem Cognit. 2013 Jul;41(5):698-715. doi: 10.3758/s13421-013-0296-7.
Theories have proposed that the maintenance of object representations in visual working memory is aided by a spatial rehearsal mechanism. In this study, we used two different approaches to test the hypothesis that overt and covert visual-spatial attention mechanisms contribute to the maintenance of object representations in visual working memory. First, we tracked observers' eye movements while they remembered a variable number of objects during change-detection tasks. We observed that during the blank retention interval, participants spontaneously shifted gaze to the locations that the objects had occupied in the memory array. Next, we hypothesized that if attention mechanisms contribute to the maintenance of object representations, then drawing attention away from the object locations during the retention interval should impair object memory during these change-detection tasks. Supporting this prediction, we found that attending to the fixation point in anticipation of a brief probe stimulus during the retention interval reduced change-detection accuracy, even on the trials in which no probe occurred. These findings support models of working memory in which visual-spatial selection mechanisms contribute to the maintenance of object representations.
理论提出,在视觉工作记忆中保持对象表示形式得益于一种空间复述机制。在这项研究中,我们使用了两种不同的方法来检验假设,即显性和隐性的视觉空间注意机制有助于在视觉工作记忆中保持对象表示形式。首先,我们在改变检测任务中跟踪了观察者在记忆可变数量的对象时的眼球运动。我们观察到,在空白保留间隔期间,参与者会自发地将目光转移到记忆数组中对象占据的位置。接下来,我们假设,如果注意机制有助于保持对象表示形式,那么在保留间隔期间将注意力从对象位置上移开,应该会在这些改变检测任务中损害对象记忆。支持这一预测的是,我们发现,在保留间隔期间,注视注视点以预期短暂的探针刺激,即使在没有探针的试验中,也会降低改变检测的准确性。这些发现支持了这样一种工作记忆模型,即视觉空间选择机制有助于保持对象表示形式。