Interference Within the Focus of Attention: Working Memory Tasks Reflect More Than Temporary Maintenance

Journal of Experimental Psychology Learning Memory and Cognition (Impact Factor: 2.86). 05/2012; 39(1). DOI: 10.1037/a0028467
Source: PubMed


One approach to understanding working memory (WM) holds that individual differences in WM capacity arise from the amount of information a person can store in WM over short periods of time. This view is especially prevalent in WM research conducted with the visual arrays task. Within this tradition, many researchers have concluded that the average person can maintain approximately 4 items in WM. The present study challenges this interpretation by demonstrating that performance on the visual arrays task is subject to time-related factors that are associated with retrieval from long-term memory. Experiment 1 demonstrates that memory for an array does not decay as a product of absolute time, which is consistent with both maintenance- and retrieval-based explanations of visual arrays performance. Experiment 2 introduced a manipulation of temporal discriminability by varying the relative spacing of trials in time. We found that memory for a target array was significantly influenced by its temporal compression with, or isolation from, a preceding trial. Subsequent experiments extend these effects to sub-capacity set sizes and demonstrate that changes in the size of k are meaningful to prediction of performance on other measures of WM capacity as well as general fluid intelligence. We conclude that performance on the visual arrays task does not reflect a multi-item storage system but instead measures a person's ability to accurately retrieve information in the face of proactive interference. (PsycINFO Database Record (c) 2012 APA, all rights reserved).

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Available from: Randall Engle
    • "WMC reflects individual voluntary attentional control and is highly correlated with fluid intelligence (Ackerman, Beier, & Boyle, 2002; Colom, Jung, & Haier, 2007; Engle, Tuholski, Laughlin, & Conway, 1999; Kane et al., 2004). In fact, individual WMC, as measured by complex working memory span tests (Daneman & Carpenter, 1980; Shah & Miyake, 1996; Turner & Engle, 1989), is correlated with a variety of tasks, such as the Stroop task, the proactive interference task, the negative priming task, and the antisaccade task (Conway, Tuholski, Shisler, & Engle, 1999; Kane & Engle, 2000, 2003; Shipstead & Engle, 2012; Unsworth, Schrock, & Engle, 2004). These tasks are known to require voluntary attentional control, which relies on the function of the lateral prefrontal cortex (Bunge, Ochsner, Desmond, Glover, & Gabrieli, 2001; Egner & Hirsch, 2005; Sweeney et al., 1996; Zysset, Muller, Lohmann, & von Cramon, 2001). "
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    ABSTRACT: Neuroimaging and behavioral evidence has suggested that the lateral prefrontal cortex is involved in individual differences in working memory capacity (WMC). However, few studies have localized the neural structures that differentiate high and low WMC individuals, considering the functional architecture of the prefrontal cortex. The present study aimed to identify a frontal region that underlies individual differences from the perspective of the hierarchical architecture of the frontal cortex. By manipulating an episodic factor of cognitive control (control in selecting an appropriate task set according to a temporal context) and using a parametric modulation analysis, we found that both highand low- WMC individuals have similar activation patterns in the premotor cortex (BA6, 8), caudal prefrontal cortex (BA44, 45), and frontopolar cortex (BA10, 11), but differed in the rostral part of the prefrontal cortex (BA46/47); high WMC individuals showed greater activation in the higher episodic control condition, whereas low WMC individuals showed reduced activation when episodic control was required. Similar patterns of activation were found in the right inferior parietal and middle/inferior temporal cortices. These results indicate that the rostral prefrontal cortex, which supports episodic cognitive control, possibly by sending a weighting signal toward the inferior parietal and middle/inferior temporal cortices that modulate saliency and sensory processing, underlies individual differences in WMC. Episodic control account, which considers the organization of the prefrontal cortex, fits well with previous findings of individual differences in WMC. Full texts are available at the link below until October 2, 2015.
    No preview · Article · Aug 2015 · Cortex
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    • "We refer to this construct as working memory capacity despite the fact that it really reflects domain-free executive attention. More specifically, our view is that WMC reflects the ability to maintain information when faced with distraction or proactive interference (Engle & Kane, 2004; Kane, Conway, Hambrick, & Engle, 2007; Shipstead & Engle, 2013). In short, WMC is not about how many chunks or units can be maintained, but about the allocation of attention to do the work necessary maintaining information in an active and quickly retrievable state without interference. "
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    ABSTRACT: Bleckley, Durso, Crutchfield, Engle, and Khanna (Psychonomic Bulletin & Review, 10, 884-889, 2003) found that visual attention allocation differed between groups high or low in working memory capacity (WMC). High-span, but not low-span, subjects showed an invalid-cue cost during a letter localization task in which the letter appeared closer to fixation than the cue, but not when the letter appeared farther from fixation than the cue. This suggests that low-spans allocated attention as a spotlight, whereas high-spans allocated their attention to objects. In this study, we tested whether utilizing object-based visual attention is a resource-limited process that is difficult for low-span individuals. In the first experiment, we tested the uses of object versus location-based attention with high and low-span subjects, with half of the subjects completing a demanding secondary load task. Under load, high-spans were no longer able to use object-based visual attention. A second experiment supported the hypothesis that these differences in allocation were due to high-spans using object-based allocation, whereas low-spans used location-based allocation.
    Full-text · Article · Nov 2014 · Memory & Cognition
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    • "One way to adjudicate between these two subtly different hy - potheses is to investigate whether memory representations do become weaker over time in situations that do not motivate active removal . This question has been debated for several decades in the literature on short - term memory and WM , and the balance of evidence is by now strongly against the notion of gradual decay or deterioration of WM representations over time ( Lewandowsky , Oberauer , & Brown , 2009 ; Oberauer & Lewandowsky , 2013 ; Shipstead & Engle , 2013 ; Souza & Oberauer , in press ) . Therefore , the assumption of active removal of no longer relevant represen - tations from WM has more credibility than the assumption of passive degradation or decay . "
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    ABSTRACT: During the retention interval of a working memory task, presenting a retro-cue directs attention to 1 of the items in working memory. Testing the cued item leads to faster and more accurate responses. We contrasted 5 explanations of this benefit: (a) removal of noncued items, (b) strengthening of the cued item, (c) protection from probe interference, (d) protection from degradation, and (e) prioritization during the decision process. Experiment 1 showed that retro-cues reduced the set size effect in a visual recognition task, and did so increasingly with more time available to use the retro-cue. This finding is predicted only by Hypotheses 1 and 2. Hypotheses 3 through 5 were ruled out as explanations of the retro-cue benefit in this experiment. In Experiments 2 and 3, participants encoded 2 sequentially presented memory sets. In half of the trials, 1 item from the first set was retro-cued during the interset interval. Retro-cues improved memory for the second set. This reloading benefit is predicted only by the removal hypothesis: Irrelevant contents are removed from working memory, freeing capacity to encode new contents. Experiment 3 also yielded evidence that strengthening of the cued item might contribute to the retro-cue effect. (PsycINFO Database Record (c) 2014 APA, all rights reserved).
    Full-text · Article · Apr 2014 · Journal of Experimental Psychology Human Perception & Performance
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