The Influence Of Cognitive Expectation On Sound-induced Flash Illusion

Sound-induced flash illusion(SIFI)is an auditory-dominated multisensory integration phenomenon,that is,when the visual flash accompanied by an unequal number of auditory sounds in 100 m s successively or sim ultaneously,individual illusive ly perceived visual flashes is equal to the num ber of auditory sounds.In the pr evious studies,they m ainly discussed the causes,neural mechanisms and influencing factors of sound-induced flash illusion.Studies have shown that the impact of sound-induced flash illusion factors mainly from top-down and bottom-up factors.Theref ore,this study is based on the classical paradigm of sound-indu ced flash illusion,a nd uses top-do wn cognitive expectation to explore the influence of top-down factors on sound-induced flash illusion.In this study,we m ainly manipulate the chang e instruction and expe rimental trials proportion to contro l the cognitiv e expectation.The exp erimental conditions used in experiment 1 and experim ent 2 were the sam e("Please judge the number of flashes"," with double flashes of 80%in the co ndition,please judge the number of flashes " and " with a flash of 80% in conditions,please judge the number of flashes "),but the proportion of experimental trials were different;Experiment 3 used three identical instructions(" Please judge the number of flashes " "Th e probability of all experim ental conditions are equal,please judge the num ber of flashes " and " The probability of all experimental conditions were equal,please judge the num ber of flashes"),the experimental trials proportion was consistent with the experiment 1.Experiment 1 found that the instructions can improve the accuracy of judging fission illusion phenom enon,and shorten the reaction tim e;Experiment 2 found that the proportion of experi mental trials were incongruent with the instructions,it still improved the accuracy of judging subjec ts fission illusion,shorten the subjects reaction time,and showed that it is not affected by the proportion of experimental trials;Experiment 3 further showed the subjects determine fission illusion is only affected by instructions,has nothing to do with the proportion of experim ental trials The experimental results show that the top-down cognitive expectation has a significant effect on the fission illusion,which can reduce the false rate of fission,that means it can improve the accuracy of fission flash,and can speed up the reaction time.But there is no significant change in the fusion flash,which is related to the instability of the fusion phenomenon.