The Number and Quality of Representations in Working Memory

Flexible-resource theories characterize working memory as a flexible resource that can store either a large number of low-quality representations or a small number of high-quality representations. In contrast, limited-item theories propose that the number of items that can be stored in working memory is strictly limited and cannot be increased by decreasing the quality of the representations. We tested these fundamentally different conceptualizations of working memory capacity by determining whether observers could trade quality for quantity in working memory when given incentives to do so. We found no evidence that observers could increase the number of representations by decreasing their quality in working memory, but observers could make such a trade-off at earlier processing stages. Our results show that the capacity limit of working memory is best characterized as a limit on the number of items that can be stored and not as a limit on a finely divisible resource that simultaneously determines the number and quality of the representations.

[1]  E. Vogel,et al.  Perceptual expertise enhances the resolution but not the number of representations in working memory , 2008, Psychonomic bulletin & review.

[2]  E. Vogel,et al.  Quantity, not quality: the relationship between fluid intelligence and working memory capacity , 2010, Psychonomic bulletin & review.

[3]  Richard C. Atkinson,et al.  Factors influencing speed and accuracy of word recognition , 1973 .

[4]  George Sperling,et al.  The information available in brief visual presentations. , 1960 .

[5]  Steven J. Luck,et al.  Visual short term memory , 2007, Scholarpedia.

[6]  W. Ma,et al.  A detection theory account of change detection. , 2004, Journal of vision.

[7]  A. Raffone,et al.  A Cortical Mechanism for Binding in Visual Working Memory , 2001, Journal of Cognitive Neuroscience.

[8]  Valerie M. Beck,et al.  Reduced capacity but spared precision and maintenance of working memory representations in schizophrenia. , 2010, Archives of general psychiatry.

[9]  H. Spekreijse,et al.  Large capacity storage of integrated objects before change blindness , 2003, Vision Research.

[10]  A Treisman,et al.  Feature analysis in early vision: evidence from search asymmetries. , 1988, Psychological review.

[11]  Jeffrey N. Rouder,et al.  Bayesian t tests for accepting and rejecting the null hypothesis , 2009, Psychonomic bulletin & review.

[12]  C. Eriksen,et al.  Allocation of attention in the visual field. , 1985, Journal of experimental psychology. Human perception and performance.

[13]  G. Shulman,et al.  Spatial determinants of the distribution of attention , 1985, Perception & psychophysics.

[14]  T. Klingberg.  Training and plasticity of working memory , 2010, Trends in Cognitive Sciences.

[15]  Edward F. Ester,et al.  Discrete resource allocation in visual working memory. , 2009, Journal of experimental psychology. Human perception and performance.

[16]  G. A. Miller.  THE PSYCHOLOGICAL REVIEW THE MAGICAL NUMBER SEVEN, PLUS OR MINUS TWO: SOME LIMITS ON OUR CAPACITY FOR PROCESSING INFORMATION 1 , 1956 .

[17]  Nelson Cowan,et al.  Working Memory Capacity , 2005 .

[18]  Richard C. Atkinson,et al.  Search and decision processes in recognition memory. , 1974 .

[19]  Xiao-Jing Wang.  Synaptic reverberation underlying mnemonic persistent activity , 2001, Trends in Neurosciences.

[20]  Edward Awh,et al.  Precision in Visual Working Memory Reaches a Stable Plateau When Individual Item Limits Are Exceeded , 2011, The Journal of Neuroscience.

[21]  Todd S Horowitz,et al.  Direction information in multiple object tracking is limited by a graded resource , 2010, Attention, perception & psychophysics.

[22]  Jeffrey W. Cooney,et al.  Top-down suppression deficit underlies working memory impairment in normal aging , 2005, Nature Neuroscience.

[23]  J. Palmer.  Attentional limits on the perception and memory of visual information. , 1990, Journal of experimental psychology. Human perception and performance.

[24]  E. Vogel,et al.  PSYCHOLOGICAL SCIENCE Research Article Visual Working Memory Represents a Fixed Number of Items Regardless of Complexity , 2022 .

[25]  G. Mandler.  Recognizing: The judgment of previous occurrence. , 1980 .

[26]  Alex O. Holcombe,et al.  Tracking the changing features of multiple objects: Progressively poorer perceptual precision and progressively greater perceptual lag , 2008, Vision Research.

[27]  Paul M Bays,et al.  Dynamic Shifts of Limited Working Memory Resources in Human Vision , 2008, Science.

[28]  S. Luck,et al.  Sudden Death and Gradual Decay in Visual Working Memory , 2009, Psychological science.

[29]  P. Cavanagh,et al.  The Capacity of Visual Short-Term Memory is Set Both by Visual Information Load and by Number of Objects , 2004, Psychological science.

[30]  George A Alvarez,et al.  How many objects can you track? Evidence for a resource-limited attentive tracking mechanism. , 2007, Journal of vision.

[31]  Denis Cousineau,et al.  Confidence intervals in within-subject designs: A simpler solution to Loftus and Masson's method , 2005 .

[32]  S. Luck,et al.  Discrete fixed-resolution representations in visual working memory , 2008, Nature.