Integrating working memory capacity and context-processing views of cognitive control

Abstract

Individuals low in working memory capacity (WMC) exhibit impaired performance on a variety of cognitive control tasks. The executive-attention theory of WMC (Engle & Kane, [2004[) accounts for these findings as failures of goal maintenance and response conflict resolution. Similarly, the context-processing view (Braver et al., [2001]) provides an explanation of cognitive control deficits observed in schizophrenia patients and older adults that is based on the ability to maintain context information. Instead of maintenance deficits, the inhibition view (Hasher, Lustig, & Zacks, [2007]) states that older adults and individuals low in WMC primarily have an impairment in the ability to inhibit information. In the current experiment, we explored the relationships among these theories. Individuals differing in performance on complex span measures of WMC performed the AX-Continuous Performance Test to measure context-processing performance. High-WMC individuals were predicted to maintain the context afforded by the cue, whereas low-WMC individuals were predicted to fail to maintain the context information. Low-WMC individuals made more errors on AX and BX trials and were slower to respond correctly on AX, BX, and BY trials. The overall pattern of results is most consistent with both the executive-attention and context-processing theories of cognitive control.

Keywords:

• Cognitive control
• Working memory
• Individual differences
• Inhibition

Acknowledgments

We thank Nash Unsworth, Whitney Hansen, and the members of the Attention & Working Memory Lab for feedback on an earlier version of this manuscript.

Notes

¹ Nine low-WMC participants were eliminated from the final sample. Four participants could not achieve 75% probe accuracy after three practice blocks and therefore did not complete any experimental blocks. Two participants did not complete the task (one due to experimenter error, the other due to a fire alarm). One participant had an overall accuracy of 66%, largely a result of near-chance performance (54%) on long AX targets. Finally, 2 participants made errors on all long BX nontargets; these individuals had no correct responses to contribute to the RT analyses and may not have understood the task instructions. Note that eliminating these last 3 low-WMC participants weakened our ability to detect the predicted WMC differences in the AX and BX conditions. In addition, including these 3 participants in the analyses did not change any of the results.

² Although the results focus on the performance on probes, cue accuracy was also assessed to ensure general compliance with task instructions. Cue accuracy was 98% for each WMC group. In order to maximize the number of observations, performance was evaluated on all trials regardless of whether the cue was correct or not. Restricting analyses to only those trials in which the cue was responded to correctly did not change the results.