The Proverties Of Object-Based Attention In Processing Bindings In Working Memory

Feature binding is one of the core problems in cognitive science.During the last decade,the mechanism of processing binding in working memory(WM)has been discussed extensively.Relevant studies mainly focused on whether processing binding in WM requires more attention than processing constituent features.Most research suggested that processing binding in WM does not require more attention.Recently,Shen et al.(2015)raised an object-based attention hypothesis in processing binding in WM,which hypothesized that object-based attention played a pivotal role in binding process in WM,and hence more object-based attention was needed in processing binding than in processing single features.However,extant studies provided only preliminary evidence for the object-based attention hypothesis.So far no study explored the properties of object-based attention in processing binding in WM.The current study aims at closing this gap.The current research adopted a dual-task paradigm,in which a secondary task consuming object-based attention was inserted into the maintenance phase of WM,to probe how the secondary task influenced the binding performance.We investigated the properties of object-based attention in binding process in WM systematically by examining four perspectives,namely,the form of binding,the degree of encoding,the state of activation in WM and the number of features composing a binding.Based on the investigation,we further distinguished a strong object-based attention hypothesis from a weak object-based attention hypothesis.The former one suggested that object-based attention in binding process of WM holds in all the four perspectives,whereas the later one suggested that the object-based attention hypothesis is restricted to certain circumstances.The current study consisted of eight experiments.In Experiments 1 to 4,the author examined the role of object-based attention in processing cross-space binding,cross-time binding and object-background binding in WM.Experiments 5 and 6 investigated whether the binding which was formed automatically during a short encoding phase and bindings which was in different activated states in WM required more object-based attention,respectively.In Experiments 7 and 8,the author examined the relationship between the number of features contained in a binding representation and the quantity of object-based attention by comparing 2-and 3-featured bindings.The main findings of the current research were shown below.(1)The secondary task consuming object-based attention led to a selective impairment to the maintenance of cross-space binding,cross-time binding and object-background binding in WM,suggesting that object-based attention plays a critical role in retaining bindings in WM regardless of binding forms.(2)When the encoding phase was shortened,the secondary object-based task selectively impaired the WM performance of binding,suggesting that object-based attention plays a critical role in retaining binding in WM regardless of encoding degree.(3)When the memory items were presented sequentially,the secondary object-based task resulted in comparable impairment to the bindings in different states of activation,suggesting that object-based attention plays a critical role in retaining binding in WM regardless of states of activation.(4)The secondary object-based task impaired the WM performance of 2-and 3-featured bindings to the same extent,suggesting that the number of features in a bound representation does not modulate the required quantity of object-based attention in WM.The results not only provided solid evidence to the object-based attention hypothesis in processing binding in WM,but also for the first time revealed the properties of object-based attention in processing binding in WM,strongly supporting a strong object-based attention hypothesis.