The Influence Of Attention Guidance On Visual Working Memory Representation

The resource that supports visual working memory(VWM)is limited,raising the question of how the brain allocates this limited resource to different objects.This question is even more interesting in ecological settings,in which objects are not equally important.Attention has been proved to play a critical role in VWM to help individual allocate the limited resources.The effect of attention on VWM representation has been explored using several methods.Visual cuingparadigm is one of the most commonly used paradigm,in which a cue is presented immediately before or following an array of to-be-remembered items.This cue typically informs participants which item will be most likely to be tested at retrieval.Visual cues improve memory for the cued item.Researchers assume that attention mediates the flexible allocation of VWM resources.More resources are allocated the the cue directed items.Reward-cuing paradigm a newly method that used by researchers to investigate the effect of attention to VWM.In this paradigm,participants are typically presented with a series of colored shapes sequentially.Before the block of trials,participants are told that one serial position(SP)is more valuable than the rest,with correct recall of that item gaining them more points.The results showed that both the final and the high reward items could gain access of focus of attention(FoA),however,the representation of both types of items are unstable and vulnerable to perceptual interference.Therefore,the mechanism of attention to VWM is not clear,and further evidence is needed.In the present study,the effects of different attention on VWM representation were further explored by manipulating either the probe value or probe frequency using recall paradigm or change detection paradigm.In the first section,the effect of different attention on VWM representations was explored by manipulating the saliency of the items or inserting a secondary task which could guide feature-based or spatial-based attention through bottom-up manner,and probe value or probe frequency which guide attention through a top-down manner.In the second section,the inhibition mechanisms of irrelevant information during VWM retention were explored by manipulating presentation format(simultaneously vs sequentially)of the items,the number of the directed items,the features of the to-be-ignored stimulus suffix.The main findings are as follows.First,when the first item was prioritized via probe values,feature-based attention disrupted the performance of the low reward items,but not for high reward items.However,when the first item was prioritized via probe frequencies,feature-based attention improved the performance of the low frequency items,but not for high frequency items.Second,when the items were simultaneous presented,prioritized items in VWM relied on the spatial-based attention regardless of prioritization format.Third,when memory items were presented sequentially,prioritized item with a high probe frequency could resist the interference.Fourth,items were more vulnerable to interference when there were two cued-items,but not when there was only one cued-item.Fifth,when the to-be ignored suffix shares features with the cued-item,it promotes the retrieval of the cued-item,but they impaired the quality of non-cued items and hinders their retrieval.Sixth,the ERP results indicated that more attentional resources were allocated to the cued-item,which enhanced its representation and also protected it from interference.In conclusion,when items were presented sequentially,feature-based attention modulated the effect of probe values and probe frequencies differently.The salient items with a low reward values were inhibited;however,the salient items with a low test frequency were not.Second,when items were presented simultaneously,prioritized items in VWM relied on the spatial-based attention regardless of prioritization format.Third,whether information in FoA is vulnerable to interference or not depends on the types of attention that works on it and the number of the items in the FoA,as well as the presentation format of the items.Fourth,attention enhanced the resolution of cued item which protect it from interference.