Abstract
BackgroundWorking memory (WM) is imperative for effective selective attention. Distractibility is greater under conditions of high (vs. low) concurrent working memory load (WML), and in individuals with low (vs. high) working memory capacity (WMC). In the current experiments, we recorded the flanker task performance of individuals with high and low WMC during low and high WML, to investigate the combined effect of WML and WMC on selective attention.Methodology/Principal FindingsIn Experiment 1, distractibility from a distractor at a fixed distance from the target was greater when either WML was high or WMC was low, but surprisingly smaller when both WML was high and WMC low. Thus we observed an inverted-U relationship between reductions in WM resources and distractibility. In Experiment 2, we mapped the distribution of spatial attention as a function of WMC and WML, by recording distractibility across several target-to-distractor distances. The pattern of distractor effects across the target-to-distractor distances demonstrated that the distribution of the attentional window becomes dispersed as WM resources are limited. The attentional window was more spread out under high compared to low WML, and for low compared to high WMC individuals, and even more so when the two factors co-occurred (i.e., under high WML in low WMC individuals). The inverted-U pattern of distractibility effects in Experiment 1, replicated in Experiment 2, can thus be explained by differences in the spread of the attentional window as a function of WM resource availability.Conclusions/SignificanceThe current findings show that limitations in WM resources, due to either WML or individual differences in WMC, affect the spatial distribution of attention. The difference in attentional constraining between high and low WMC individuals demonstrated in the current experiments helps characterise the nature of previously established associations between WMC and controlled attention.
Highlights
Over the last two decades, research findings demonstrating an association between working memory capacity (WMC) and executive attention capabilities have accumulated [1]
In Experiment 2, the spatial distribution of attention was mapped in individuals with low or high WMC, and under either low or high working memory load (WML) by measuring the congruency effects from distractors that appeared at varying distances from the target
Most importantly when the availability of Working memory (WM) was most compromised, in the low WMC group under high WML, the congruency effects were best described by an even more dispersed Mexican-hat profile. These results replicate recent findings of the effect of WML effect on the spatial distribution of distractor effects [24], and extend on these by showing firstly that limitations in WM resources due to individual variations in WMC cause a similar dispersion in the attentional profile, and secondly that the two factors of WMC and WML together have an additive influence on attentional constraining, since the profile became even more dispersed when low WMC and high WML cooccurred
Summary
Over the last two decades, research findings demonstrating an association between working memory capacity (WMC) and executive attention capabilities have accumulated [1]. In tasks of visual selective attention, individuals with high WMC are typically more effective at selectively attending to relevant, and overcoming the influence of irrelevant information, compared to individuals with low WMC [2,3,4,5,6,7]. The interference effects of visual distractors are greater for low, compared to high WMC individuals when performing the Eriksen flanker task [3]. Such findings have led to the suggestion that attentional control mechanisms are more efficient in individuals with greater, compared to those with more limited, working memory (WM) resources. We recorded the flanker task performance of individuals with high and low WMC during low and high WML, to investigate the combined effect of WML and WMC on selective attention
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
