The Effect Of Executive Attention Load On Retro-cue Effect In Visual Working Memory

Visual working memory(VWM)is a limited capacity system responsible for the temporary storage and processing of visual information.Attention is a cognitive mechanism for selecting information during cognitive processing,and VWM and attention are two interdependent cognitive systems.VWM has a limit capacity: Only three to four representations at most at a time can be maintained accessibly.Selective attention controls which information gets access to VWM,allowing the filtering out of irrelevant inputs.The retro-cue effect refers to the fact that during VWM retention,memory performance can be improved by a valid cue pointing to an item compared to a neutral cue.However,whether the retro-cue effect requires executive attention is still controversial.It had been found that the retro-cue effect does not require sustained visual or executive attention by presenting a secondary task or visual masks within 500～1000ms after the retro-cue has disappeared.While other studies found that the retro-cue effect indeed suffers and becomes smaller when the secondary task occurs close to the cue onset.The retro-cue effect in VWM therefore needs executive attention and the internal prioritization processing triggered by the cue is likely to be severely disturbed only when the interference is strong.Therefore,how does executive attention impact on the retro-cue effect in VWM? It remains unclear.Exploration of this issue could contribute to understanding the mechanisms by which the retro-cue effect arises in VWM and the relationship between attention and VWM,and provide new evidence for explaining the controversy over whether the retro-cue effect requires attention.In this study,four experiments were designed to explore these issues via conjunction with the retro-cue paradigm and the dual-task paradigm,by using behavioral experiment and event-related potential(ERP)technique.In Experiment 1,whether and when the retro-cue effect required executive attention during the VWM retention was explored by inserting a secondary task that consumed executive attention after the retro-cue disappeared and manipulating the interval between the retro-cue and the secondary task.The result showed that,when the secondary task was presented close to the retro-cue,the retro-cue effect was impaired,and that this effect gradually diminished or even disappeared as time increased,with the retro-cue effect no longer being disturbed by secondary task when the interval between the cue and the secondary task was 500 ms.These results suggest that there is a time window in which the effect of executive attention on the retro-cue effect of VWM,and that additional attention processing that occurs within this time window affects the retro-cue effect.Auditory and visual secondary task were used to consume executive attention in Experiments 2 and 3,respectively,to explore the effect of task load on the retro-cue effect in VWM and whether this effect has cross-channel consistency by manipulating secondary task load.The results found that regardless of the secondary task,the retro-cue effect was reduced by low load secondary task,while high load secondary task had no effect on the retro-cue effect.These results indicated that the retro-cue effect is moderated by the cognitive resources consumed by extra attentional processing,and the effects were consistent in auditory channel and visual channel.The event-related potential(ERP)technique was used to explore the mechanisms by which low load executive attention affects the retro-cue effect in VWM in Experiment 4,using the negative slow wave(NSW)and the N2 components as neural indicators.The results showed that the amplitude of NSW induced by neutral cues was larger than that induced by valid cues,and the N2 induced by the with secondary task condition was larger than that induced by the without secondary task condition.These results suggested that the valid cues lead to the focusing of attention on only a subset of the initially encoded information,thereby reducing working memory load.Importantly,compared to the without secondary task condition,more cognitive control resources were invested to inhibit the processing of secondary task in the secondary task condition,thus facilitating the internal prioritization processing by the retro-cue.The main conclusions are as follows:(1)Executive attention is required for the retro-cue effect during the shorter window after the VWM retention phase retro-cue are presented.(2)Executive attentional load has a moderating effect on the retro-cue effect in VWM.Compared with high load,low load attentional processing reduce the retro-cue effect,and it has cross-channel consistency.(3)During the VWM retention,the potential mechanism by which low load executive attention reduces the retro-cue effect may be: the executive attention processing in the shorter period after the retro-cue consumes cognitive control resources and inhibits the processing of secondary task,and increases the cognitive control resources obtained by the cueing item.