The Effect Of Visual And Verbal Working Memory Load On Visual Detection

The influence of working memory load on selective detection has attracted attention in the recent decade.Working memory is a multi-component system,in which visual and verbal working memory are two key components in charge of information storage.Currently,the influence mechanism of the two types of working memory load on selective attention is still in debate.Moreover,it has been implicitly assumed that the two types of load functioned in distinct ways.However,previous studies have not correctly manipulated the verbal working memory load and have different range of memory items.Thus,it is difficult for researchers to directly compare the influence of the two types of load on selective attention.Recent studies of working memory have revealed that higher level brain cortices send feedback signal and reactivate the primary visual cortices.This finding implies that if the memorized stimuli are presented in a visual format,these two types of load may function in a manner similar to perceptual load until it reaches the capacity of working memory.The current study tested this novel prediction in three experiments(6 sub-experiments),by adopting a visual detection task paradigm.Visual and verbal working memory load was manipulated by requiring participants to memorize colors and letters,respectively.During the working memory maintenance phase,participants had to fulfill a low priority visual detection task.Experiment 1 examined the influence of visual working memory load by using colored patches as the stimuli.Experiment 2 examined the influence of verbal working memory load by using English letters as the stimuli.Finally,Experiment 3 examined the influence of the two loads,by requiring the participants to memorize colors and letters of the same set of colored letters.In three experiments,we consistently found that as the working memory load increased,the detection sensitivity of low-priority stimuli significantly reduced.However,when the working memory load reached its capacity,the detection sensitivity stopped decreasing.The following conclusion can be drawn:(1)Visual and verbal working memory load have the same influence on visual detection.(2)The amount of information stored in visual and verbal working memory is the key factor that directly influences visual detection.