Attention Relieves Visual Crowding:Dissociable Effects Of Exogenous And Endogenous Attention

The phenomenon of visual crowding is common in life,and it means that the reduced recognition accuracy of targets surrounded by distracting stimuli compared to target presented alone in the peripheral visual field.According to the attentional resolution model,attention is an important factor influencing visual crowding.Exogenous attention has been found to relieve visual crowding to some extent,whereas the effect of endogenous attention on visual crowding is not clear.At the same time,few studies have explored the different effects of the two types of attention on visual crowding in different time course.The present study combined behavioral and event-related potential(ERP)techniques to investigate the different effects of endogenous and exogenous attention on visual crowding and their neural mechanisms.The study combined the cue-target and visual crowding paradigms to explore their different effects.Experiment 1 explored the effect of both types of attention on visual crowding with five different SOAs and 100% cue predictive validity.It was found that both attentional cues alleviated visual crowding,but endogenous attention acted to reduce it after 275 ms,while exogenous attention worked at 100 ms.In addition,the effect of exogenous attention was more significant than that of endogenous attention.When the cue predictive validity of Experiment 2 was 50%,it was found that the correct rate of valid cues for exogenous attention was significantly greater than the other two cues,while similar results did not exist for endogenous attention.This suggests that endogenous attention is affected by cue predictive validity,while exogenous attention is not affected by cue predictive validity.Experiment 3 combined ERP techniques to explore the neural mechanisms underlying the effects of both types of attention on visual crowding at 75% cue predictive validity.The behavioral results of Experiment 3 revealed that endogenous attention was significantly more correct for valid cues than invalid cues only in long SOA,whereas exogenous attention was more correct for valid cues than invalid cues in all SOA.ERP results showed that endogenous attention significantly alleviated the inhibition of the N1 component by visual crowding in long SOA,whereas exogenous attention was able to significantly reduce the inhibition produced by crowding on N1 in short SOA.In addition,the P3 of exogenous attention to valid cues was lower than that of invalid cues in short SOA.In conclusion,this study found that both exogenous and endogenous attention could alleviate the interference of visual crowding.However,the effect of exogenous attention was larger than that of endogenous attention.Second,exogenous attention acts on visual crowding earlier than endogenous attention.Endogenous attention is affected by the magnitude of cue predictive validity,whereas exogenous attention is not affected by cue predictive validity.Finally,it was also found that both types of attention moderated the effects of visual crowding on N1,but there were temporal differences.Also exogenous attention to the effect of visual crowding evoked different P3 wave amplitude states.In summary,the present study learned that both exogenous and exogenous attention can affect visual crowding,but they differ in effect size,time course,and neural mechanisms.