The Role Of Object-based Attention,Momery Load On Incidental Binding In Visual Working Memory

Visual working memory is a limited storage and processing system.Researchers are keen to explore the capacity and storage mode of objects in visual working memory,and put forward several representative theoretical hypotheses.There is a phenomenon in the study,if an object is composed of feature "A" and "B",when the characteristic feature of "A" is the target feature,we only encode and maintain the feature "A",and do not process the irrelevant features "B".But there is another kind of phenomenon,the feature "B" is not processed when we encode and maintain the target feature "A" we have just mentioned,when the feature of "B" as the target feature,the processing of the feature "B" is often accompanied by an incidental encoding of the irrelevant feature "A"(i.e.object-based encoding),this produces an incidental binding of the target feature "B" to the irrelevant feature "A".At present,there is a dispute about the mechanism of the incidental binding,the focus of the dispute is focused on the role of the object-attention in it.Adopting change-detect paradigm,we explore the formation in incidental binding whether to object-attention resources,and to explore the form of incidental binding whether is affected by the memory load of the target feature.This study includes three experiments,each experiment was divided into the experimental a part and the experimental b part.Part of a uses some experimental materials which are made up of different streams processing features(color and location),part of b uses experimental materials that are made of characteristics which are processed in the same stream(color and shape).Experiment 1 uses a single-probe change detection paradigm,Experiment 1a verifies that there is an incidental binding in colors and their occupancy positions,within the single factor within-subjects design,the independent variable is the memory task,which consists of two levels: color memory task and location memory task.The results show that in the location memory task,there is no significant difference between the accuracy and reaction times of the intact and recombined conditions,showed that subjects only memory of the location information;however,in the color memory task,the accuracy and reaction times was better in intact condition than in recombined condition,have appeared the binding effect and an incidental binding of location and color in the color memory task.Experiment 1b to investigate whether there is an incidental binding in objects consisting of colors and shapes,within the single factor within-subjects design,the independent variable is the memory task,which consists of two levels: color memory task and shape memory task.The results show that in the color memory task,there is no significant difference between the accuracy and reaction times of the intact and recombined conditions,showed that subjects only memory the color information;however,in the shape memory task,the accuracy and reaction times was better in intact condition than in recombined condition,have appeared the binding effect and an incidental binding of color and shape in the shape memory task.Experiment 2 on the basis of experiment 1 that appear to the memory condition of incidental binding for further exploration,based on the visual working memory task,in the storage stage keep adding the mental rotation task to consume to the attentional resources that used to maintain the object binding,explore the object-attention resources on the incidental binding of irrelevant information.Experiment 2a is a dual task,comprehensive analysis of color memory tasks with experiment 1a,it is designed for single factor between subjects,the independent variable is the task type,which consists of two levels: single task and dual task.Results showed that there is no significant difference between the accuracy and reaction times of the intact and recombined conditions when there is a mental rotation task,which indicates that object-attention resources affect the incidental binding of irrelevant location information.This experiment 2b with the experiment design of experiment 2a was similar,but only the difference of experimental materials,it is found that there is no significant difference between the accuracy and reaction times of the intact and recombined conditions when there is a mental rotation task,which indicates that the object-attention resources affects the incidental binding to the irrelevant color information.Experiment 3 further explored that appear to the memory condition of incidentalbinding in Experiment 1,and increased the number of experimental materials in memory stage,so as to explore whether the increase of target characteristic memory load would affect the encoding of irrelevant information and the formation of the incidental binding.Experiment 3a is a high color memory load task,comprehensive analysis of color memory tasks with experiment 1a,it is designed for single factor between subjects,the independent variable is the memory load,which consists of two levels: low color memory load and high color memory load.It is found that there is no significant difference between the accuracy and reaction times of the intact and recombined conditions in high color memory load,which indicates that the increase of the memory load of the target color information affects the incidental binding of irrelevant location information.This experiment 3b with the experiment design of experiment 3a was similar,it is found that the accuracy and reaction times was better in intact condition than in recombined condition,have appeared the binding effect and which indicates that the increase of the memory load of the target shape information does not affect the incidental binding of irrelevant color information of the individual.To sum up,we can draw the conclusion that:(1)In visual working memory,incidental binding exist not only in the features that are processed by two different streams of what and where(color,location),but also in the features composed of what stream processing dimensions(color,shape).(2)In the features processed by the two streams of what and where,object-attention resources affects the formation of the incidental binding when memorizing color information,and the memory load of the color information also affects the incidental binding of color information and location information.(3)In the features between the dimensions processed by the what stream,object-attention resources affects the formation of the incidental binding when memorizing shape information,but the memory load of the shape information did not affect the shape information incidental binding with color information.