Sequential Whole Report Accesses Different States in Visual Working Memory

• Published in: Journal of experimental psychology. Learning, memory, and cognition Vol. 44; no. 4; pp. 588 - 603
• Main Authors: Peters, Benjamin, Rahm, Benjamin, Czoschke, Stefan, Barnes, Catherine, Kaiser, Jochen, Bledowski, Christoph
• Format: Journal Article
• Language: English
• Published: United States American Psychological Association 01.04.2018
• Subjects: Accuracy; Acoustics; Adult; Attention - physiology; Cognitive Processes; College Students; Cues; Female; Foreign Countries; Humans; Interference (Learning); Male; Memory, Short-Term - physiology; Mental Recall - physiology; Pattern Recognition, Visual - physiology; Recall (Psychology); Short Term Memory; Space Perception - physiology; Statistical Analysis; Visual Perception; Visual Stimuli; Young Adult; Germany
• ISSN: 0278-7393; 1939-1285
• DOI: 10.1037/xlm0000466

Working memory (WM) enables a rapid access to a limited number of items that are no longer physically present. WM studies usually involve the encoding and retention of multiple items, while probing a single item only. Hence, little is known about how well multiple items can be reported from WM. Here we asked participants to successively report each of up to 8 encoded Gabor patches from WM. Recall order was externally cued, and stimulus orientations had to be reproduced on a continuous dimension. Participants were able to sequentially report items from WM with an above-chance precision even at high set sizes. It is important that we observed that precision varied systematically with report order: It dropped steeply from the first to the second report but decreased only slightly thereafter. The observed trajectory of precision decrease across reports was better captured as a discontinuous rather than an exponential function, suggesting that items were reported from different states in visual WM. The following 3 experiments replicated these findings. In particular, they showed that the observed drop could not be explained by a retro-cueing benefit of the first report, a longer delay duration for later reports or a visual interference effect of the first report. Instead, executive interference of the first report reduced precision of subsequent reports. Together, the results show that a sequential whole-report procedure allows the assessment of qualitatively different states in visual WM.