The Capacity of Visual Short-Term Memory is Set Both by Visual Information Load and by Number of Objects

By George A. Alvarez, Patrick Cavanagh. Psychology Science, 2004

1,382 citations recorded by the source corpus.

Previous research has suggested that visual short-term memory has a fixed capacity of about four objects. However, we found that capacity varied substantially across the five stimulus classes we examined, ranging from 1.6 for shaded cubes to 4.4 for colors (estimated using a change detection task). We also estimated the information load per item in each class, using visual search rate. The changes we measured in memory capacity across classes were almost exactly mirrored by changes in the opposite direction in visual search rate (r2 = .992 between search rate and the reciprocal of memory capacity). The greater the information load of each item in a stimulus class (as indicated by a slower search rate), the fewer items from that class one can hold in memory. Extrapolating this linear relationship reveals that there is also an upper bound on capacity of approximately four or five objects. Thus, both the visual information load and number of objects impose capacity limits on visual short-term memory.

Subfields: Cognitive Neuroscience, Human-Computer Interaction

View Paper: https://www.semanticscholar.org/paper/ed8e62f3d3699aea2b701a85c7d16b009f043670

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Citations in the corpus

Discrete fixed-resolution representations in visual working memory (2008, background): “We observed that decreasing the masking interval produced a large decline in Pm (F(1,7) 5 47.”
The Distributed Nature of Working Memory. (2017, background): “Similarly, and in accordance with the flexible allocation of memory resources [182,183,191], higher cortical areas can retain larger chunks of low-level features that would be difficult to store individually in lower level regions.”
Feature-based memory-driven attentional capture: visual working memory content affects visual attention. (2006, neutral): “…can typically attend to, track, tag, enumerate, and retain a maximum of around four items simultaneously in both attention and working memory tasks (Alvarez & Cavanagh, 2004; Burkell & Pylyshyn, 1997; Cowan, 2000; Luck & Vogel, 1997; Mandler & Shebo, 1982; Pashler, 1988b; Phillips, 1974; Pylyshyn…”
Visual memory for natural scenes: Evidence from change detection and visual search (2006, result): “3 This estimate is consistent with independent estimates of VSTM capacity for complex objects ( Alvarez & Cavanagh, 2004 ).”
The precision of visual working memory is set by allocation of a shared resource (2009, background): “Our findings are equally inconsistent with the several " hybrid " models that have been proposed ( Alvarez & Cavanagh , 2004 ; Awh et al .”
Visual working memory for simple and complex visual stimuli (2005, positive): “In Alvarez and Cavanagh’s (2004) study, informational load was an excellent predictor of change detection performance, with a correlation coefficient of .996 between visual search slope and estimated VWM capacity. In this study, we asked whether the observed performance limitation in change detectio”
THE COGNITIVE NEUROSCIENCE OF WORKING MEMORY (2007, result): “One open question is that of the influence of object complexity – contrary to the findings of Vogel et al. (2001), others have found that visual short-term memory capacity declines with increasing object complexity (e.g., Alvarez & Cavanagh, 2004).”
Hierarchical Encoding in Visual Working Memory (2010, background): “Current theories model visual working memory as a flexible resource that is quantized into slots (Zhang & Luck, 2008) or continuously divisible (Alvarez & Cavanagh, 2004; Bays & Husain, 2008; Wilken & Ma, 2004).”
A taxonomy of external and internal attention. (2011, positive): “At the same time, increasing the complexity of features reduces overall capacity (Alvarez & Cavanagh 2004, Todd & Marois 2004, Xu & Chun 2006; but see Awh et al. 2007).”
Interpretable Credit Application Predictions With Counterfactual Explanations (2018, neutral): “This problem is of particular importance given that it has been showed that human short-term memory is unable to retain a large number of information units Vogel et al. [2001], Alvarez and Cavanagh [2004].”
Capacity limits of information processing in the brain. (2005, background): “Although the capacity of VSTM is generally estimated to be about 4 items [28‐30], it is set not only by the number of objects but also by the complexity of each object [ 31 ].”
The Effect of Visual–Chunking–Representation Accommodation on Geometry Testing for Students with Math Disabilities (2012, background): “The capacity of visual working memory is typically limited to approximately four visual items, and people usually fail to hold or manipulate additional items beyond their visual working memory capacity (Alvarez & Cavanagh, 2004; Cowan, 2001; Pashler, 1988).”