The Storage Of Statistical Summarv Representation In Visual Working Memory

Working memory is a system with limited capacity,which is one of the major components in cognitive process,and it became the focus of cognitive psychology.In the past,the study of visual work memory(VWM)focused on the storage of individual objects.However,real life is full of information,and in addition to scattered individual objects,there are a large number of objects in groups.The study in visual perception shows that when there is a group of similar stimulus,the visual system will extract the statistical properties of the ensemble,and form the statistical summary representation,thus saving the cognitive resources and improving the overall cognitive performance.Until now,we do not yet understand the storage of summary statistical representation in VWM.Change-detection paradigm is adopted in this study,the participants need to remember the average size of each disc groups.Experiment 1 measured the capacity of the summary statistical representations in VWM.Experiment 2 focused on whether the memory of summary statistical representation depends on the memory of individual stimulus.Experiment 3 investigated whether the number of individuals in ensemble will affect the storage of statistical summary representation in VWM.In experiment 4 we further manipulated the retention interval of the memory array to check how the summary statistical representation remains in VWM.The following results were obtained:(1)VWM can store approximately two statistical summary representations.(2)The memory of statistical summary representations did not depend on the memory of all the individuals.(3)The number of objects within group did not affect the memory performance.(4)The summary statistical representation in working memory decayed rapidly in 1 seconds,declined moderately in 1-2 seconds,and remained relatively stable in 2-4 seconds.The summary statistical representation can be stably maintained in the visual working memory for at least 4s.The above results show that in the face of a large number of homogeneous visual objects,the visual working memory can encode and store the summary statistical representation of multiple sets of objects,so as to realize the storage of a large amount of visual information with limited capacity.