Memory & Cognition

, Volume 43, Issue 2, pp 226–236 | Cite as

Shortened complex span tasks can reliably measure working memory capacity

  • Jeffrey L. FosterEmail author
  • Zach Shipstead
  • Tyler L. Harrison
  • Kenny L. Hicks
  • Thomas S. Redick
  • Randall W. Engle


Measures of working memory capacity (WMC), such as complex span tasks (e.g., operation span), have become some of the most frequently used tasks in cognitive psychology. However, due to the length of time it takes to complete these tasks many researchers trying to draw conclusions about WMC forgo properly administering multiple tasks. But can the complex span tasks be shortened to take less administration time? We address this question by splitting the tasks into three blocks of trials, and analyzing each block’s contribution to measuring WMC and predicting fluid intelligence (Gf). We found that all three blocks of trials contributed similarly to the tasks’ ability to measure WMC and Gf, and the tasks can therefore be substantially shortened without changing what they measure. In addition, we found that cutting the number of trials by 67 % in a battery of these tasks still accounted for 90 % of the variance in their measurement of Gf. We discuss our findings in light of administering the complex span tasks in a method that can maximize their accuracy in measuring WMC, while minimizing the time taken to administer.


Working memory Intelligence Individual differences 



This work was supported by grants from the Office of Naval Research (N00014- 12-1-0406 and N00014-12-1-1011) and the Center for Advanced Study of Language (H98230-07-D-0175 and H98230-07-D-0175) to Randall W. Engle.


  1. Ackerman, P. L., Beier, M. E., & Boyle, M. O. (2005). Working memory and intelligence: The same or different constructs? Psychological Bulletin, 131, 30–60.CrossRefPubMedGoogle Scholar
  2. Barch, D. M., Berman, M. G., Engle, R., Jones, J. H., Jonides, J., MacDonald, A., … Sponheim, S. R. (2009). CNTRICS final task selection: working memory. Schizophrenia Bulletin, 35, 136-152.Google Scholar
  3. Brown, W. (1910). Some experimental results in the correlation of mental abilities. British Journal of Psychology, 3, 296–322.Google Scholar
  4. Conway, A. R., Kane, M. J., Bunting, M. F., Hambrick, D. Z., Wilhelm, O., & Engle, R. W. (2005). Working memory span tasks: A methodological review and user’s guide. Psychonomic Bulletin & Review, 12, 769–786.CrossRefGoogle Scholar
  5. Cowan, N., Elliott, E. M., Scott Saults, J., Morey, C. C., Mattox, S., Hismjatullina, A., & Conway, A. R. (2005). On the capacity of attention: Its estimation and its role in working memory and cognitive aptitudes. Cognitive Psychology, 51, 42–100.CrossRefPubMedCentralPubMedGoogle Scholar
  6. Ekstrom, R. B., French, J. W., Harman, H. H., & Dermen, D. (1976). Manual for kit of factor-referenced cognitive tests (pp. 109-113). Princeton, NJ: Educational Testing Service.Google Scholar
  7. Engle, R. W. (2002). Working memory capacity as executive attention. Current Directions in Psychological Science, 11, 19–23.CrossRefGoogle Scholar
  8. Engle, R. W., & Kane, M. J. (2004). Executive attention, working memory capacity, and a two-factor theory of cognitive control. In B. Ross (Ed.), The Psychology of Learning and Motivation (Vol. 44, pp. 145–199). NY: Elsevier.Google Scholar
  9. Engle, R. W., Tuholski, S. W., Laughlin, J. E., & Conway, A. R. A. (1999). Working memory, short-term memory and general fluid intelligence: A latent variable approach. Journal of Experimental Psychology: General, 128, 309–331.CrossRefGoogle Scholar
  10. Feldt, L. S. (1969). A test of the hypothesis that Cronbach’s alpha reliability coefficient is the same for two tests administered to the same sample. Psychometrika, 45, 99–105.CrossRefGoogle Scholar
  11. Gevins, A., & Cutillo, B. (1993). Spatiotemporal dynamics of component processes in human working memory. Electroencephalography and Clinical Neurophysiology, 87, 128–143.CrossRefPubMedGoogle Scholar
  12. Harrison, T. L., Shipstead, Z., Hicks, K. L., Hambrick, D. Z., Redick, T. S., & Engle, R. W. (2013). Working memory training may increase working memory capacity but not fluid intelligence. Psychological Science, 24, 2409–2419.CrossRefPubMedGoogle Scholar
  13. Heinrichs, R. W., Goldberg, J. O., Miles, A. A., & McDermid Vaz, S. (2008). Predictors of medication competence in schizophrenia patients. Psychiatry Research, 157, 47–52.CrossRefPubMedGoogle Scholar
  14. Kail, R. V. (2007). Longitudinal evidence that increases in processing speed and working memory enhance children's reasoning. Psychological Science, 18, 312–313.CrossRefPubMedGoogle Scholar
  15. Kane, M. J., Hambrick, D. Z., & Conway, A. R. A. (2005). Working memory capacity and fluid intelligence are strongly related constructs: Comment on Ackerman, Beier, & Boyle (2005). Psychological Bulletin, 131, 66–71.CrossRefPubMedGoogle Scholar
  16. Kane, M. J., Hambrick, D. Z., Tuholski, S. W., Wilhelm, O., Payne, T. W., & Engle, R. W. (2004). The generality of working memory capacity: A latent variable approach to verbal and visuospatial memory span and reasoning. Journal of Experimental Psychology: General, 133, 189–217.CrossRefGoogle Scholar
  17. Kyllonen, P. C., & Christal, R. E. (1990). Reasoning ability is (little more than) working-memory capacity?! Intelligence, 14, 389–433.CrossRefGoogle Scholar
  18. Lee, J., & Park, S. (2005). Working memory impairments in schizophrenia: a meta-analysis. Journal of Abnormal Psychology, 114, 599–611.CrossRefPubMedGoogle Scholar
  19. Loehlin, J. C. (2004). Latent variable models: An introduction to factor, path, and structural equation analysis. Chicago: Psychology Press.Google Scholar
  20. Luck, S. J., & Vogel, E. K. (1997). The capacity of visual working memory for features and conjunctions. Nature, 390, 279–281.CrossRefPubMedGoogle Scholar
  21. Oberauer, K., Schulze, R., Wilhelm, O., & Süß, H. (2005). Working memory and intelligence—their correlation and their relation: Comment on Ackerman, Beier, & Boyle (2005). Psychological Bulletin, 131, 61–65.CrossRefPubMedGoogle Scholar
  22. Raven, J., Raven, J. C., & Court, J. H. (1998). Manual for Raven's Progressive Matrices and Vocabulary Scales. Section 4: The Advanced Progressive Matrices. San Antonio, TX: Harcourt Assessment.Google Scholar
  23. Redick, T. S., Broadway, J. M., Meier, M. E., Kuriakose, P. S., Unsworth, N., Kane, M. J., & Engle, R. W. (2012). Measuring working memory capacity with automated complex span tasks. European Journal of Psychological Assessment, 28, 164–171.CrossRefGoogle Scholar
  24. Schmader, T., & Johns, M. (2003). Converging evidence that stereotype threat reduces working memory capacity. Journal of Personality and Social Psychology, 85, 440–452.CrossRefPubMedGoogle Scholar
  25. Shipstead, Z., Harrison, T. L., Trani, A. N., Redick, T. S., Sloan, P., Bunting, M. F., … Engle, R. W. (2014). Working memory capacity and executive functions, Part 1: General fluid intelligence. Manuscript submitted for publication.Google Scholar
  26. Shipstead, Z., Redick, T. S., & Engle, R. W. (2012). Is working memory training effective? Psychological Bulletin, 138, 628–654.CrossRefPubMedGoogle Scholar
  27. Spearman, C. C. (1910). Correlation calculated from faulty data. British Journal of Psychology, 3, 271–295.Google Scholar
  28. Thurstone, L. L. (1938). Primary mental abilities. Psychometric monographs.Google Scholar
  29. Turner, M. L., & Engle, R. W. (1989). Is working memory capacity task dependent? Journal of Memory and Language, 28, 127–154.CrossRefGoogle Scholar
  30. Unsworth, N., Redick, T. S., Heitz, R. P., Broadway, J. M., & Engle, R. W. (2009). Complex working memory span tasks and higher-order cognition: A latent-variable analysis of the relationship between processing and storage. Memory, 17, 635–654.CrossRefPubMedGoogle Scholar
  31. Unsworth, N., Heitz, R. P., Schrock, J. C., & Engle, R. W. (2005). An automated version of the operation span task. Behavior Research Methods, 37, 498–505.CrossRefPubMedGoogle Scholar
  32. Wilhelm, O., Hildebrandt, A., & Oberauer, K. (2013). What is working memory capacity, and how can we measure it? Frontiers in Psychology, 4. Google Scholar
  33. Wittman, W. W. (1988). Multivariate reliability theory. Principles of symmetry and successful validation strategies. In J. R. Nesselroade & R. B. Cattell (Eds.), Handbook of multivariate experimental psychology (2nd ed.). Perspectives on individual differences. (pp. 505-560). New York: Plenum.Google Scholar

Copyright information

© Psychonomic Society, Inc. 2014

Authors and Affiliations

  • Jeffrey L. Foster
    • 1
    Email author
  • Zach Shipstead
    • 2
  • Tyler L. Harrison
    • 1
  • Kenny L. Hicks
    • 1
  • Thomas S. Redick
    • 3
  • Randall W. Engle
    • 1
  1. 1.Georgia Institute of Technology, School of PsychologyAtlantaUSA
  2. 2.Department of Social and Behavioral SciencesArizona State UniversityTempeUSA
  3. 3.Department of Psychological SciencesPurdue UniversityWest LafayetteUSA

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