Entering The Focus Of Attention In Working Memory:the Interaction Between Internal And External Guidance

It has been documented that the representations in working memory(WM)are not equal in terms of activated level.Among them,one item has the highest activation level and hence has a privileged status,enabling it particularly easy and quick to be accessed.Researchers have conceptualized this phenomenon by the notion of a focus of attention(FoA)in WM.There are two paths for the information entering the FoA,namely external guidance and internal guidance.The external guidance works on the external stimuli during the WM encoding phase(e.g.,a singleton in the memory array),whereas the internal guidance works on the already stored representations in WM(e.g.,giving a retro-cue during the maintenance phase of WM).Ample studies have been conducted in revealing the mechanisms of FoA entry.However,all the extant studies focused on one path of entering FoA;no study so far has investigated the interaction between the internal guidance and external guidance when both types of guidance exist and have different to-be-guided targets.The answer to this question will shed important light on both the mechanisms of FoA and the dynamic processing of WM.To this end,the current study addressed this issue by inserting a color singleton into the memory array of a conventional retro-cue paradigm,in which a retro-cue was displayed during the WM maintenance phase.We examined the interaction between internal and external guidance by checking whether the singleton effect(i.e.,better performance for the singleton relative to non-singleton items)could be modulated by the following retro-cue.In four experiments,we found that the singleton effect gradually disappeared due to the appearance of the retro-cue,which was further modulated by the processing time(Experiments 1 and 2)and depth(Experiment 3)of the retro-cue,as well as the relative validity of the guidance(Experiment 4).Overall,these results suggest that external and internal guidance share the same cognitive resources;when there is a conflict between the two guidance,the one having a higher validity will have the right to access FoA.