Can Fixation Impact IOR?

In the study of Ponser and Cohen(1984),the spatial cue paradigm was used to present two stimuli(cue S1 and target S2),randomly appearing on the left or right,and the subjects were asked to respond to them.They found that when the stimulus-onset asynchrony(SOA)is less than 300 ms,the respond to the target presented at the same position(cued)were faster than the cues and target at different locations(uncued),which there is a facilitation effect;And when the SOA is longer,greater than 300 ms,participants reacted to the cued location was slower than the unced location.Ponser et al.(1985)referred to this inhibition as inhibition of return,or IOR.By studying the inhibition mechanism,this kind of phenomenon occurred with two pathway activation,one is the output mechanism(reflecting a response bias)and the other is the input mechanism(a deficit or repeated sensory inhibition at the cued location).In Taylor&Klein(2000),it was found that when the eye movement system was activated,the output-based inhibition of return was produced.When the eye movement system were inhibited,the input-based inhibition of return is produced.This discovery laid the foundation for two flavours of theories.In the experiment,there was no significant difference in the IOR effect when the four cues and targets were observed.In Wang et al.(2012)years of study,used the similar experimental design,and asked to do the same reflection,when made participantssaccadic to the center cues ? peripheralcues and peripheral target,they found that,in the peripheralcues,inhibition of return effect significantly greater than the amount of which the cues were center cues.They believe that when the eye movement system is activated,both input-and output-based inhibition of return can be activated at the same time under the peripheralcues conditions,which is the two-component theory.In this study,Eyelink technology was used to explore the causes of this difference and the effects on the inhibition of return,and to clarify and improve the theory of IOR.In experiment 1,by using the 2cue(cued/uncued)x 2 central fixation(exist/unexist)within the subjects of design,and asked participants to make saccadic for peripheral cues and targets,we will demonstrate the conclusion,"peripheral cues and peripheral targets would produce the two component inhibition of return",is influenced by whether the central fixationpoint exist or not.The results show that: the main effect of the cue is significant,and the main effect of the central fixation is significant.From this,we can find that the central fixation point will affect the inhibition of return.In experiment 2,we will verify whether the inhibition of return effect is affected by the STD,which produced by the second cued of the central fixation point.We use peripheral target with the different colors which divided into two blocks,asking participants to make saccadic for cues and target.In the red or yellow targets block,each test time will present a kind of color picturein the end andasking participants to determine whether the picture is as same as the target color.The 2 x 2 subjects were designed,and the independent variables were cue(cued,uncued),target types(red or yellow,black),and asked participants to make saccadic reaction to the S1 and S2.The results show that the maineffect of the cue type is significant,the main effect of target type is not significant,making a single factor analysis of IOR,the results showed that,in the two kinds of experimental conditions,inhibition of return effect does not exist significant differences.When asked to judge promoted to the target position of target color processing,inhibition of return had changed,because the peripheral targets is contained in the return of an adverse ingredients.Experiments in the first set of tests will not remove the central fixation point,but the results and reaction time of the second test has unsignificant difference,so that the existence of the central fixation point inhibits foreign weeks perceptual processing,which caused the STD.Compere with the result of Taylor and Klein(2000),if it is caused by STD,when removing the central fixation point,under the condition of four types of inhibition of return quantity will have the same increase,unlike the result of Wang's(2012),that the amount of inhibition of return in SM task and M task would grew at the same rate.Therefore,in the experiment 3,we will explore the role of the central fixation point under the M task,using the2cue(cued,uncued)x 3cue conditions(the central cue and the central fixation point,the central cue and no central fixation point,peripheral cue and central fixation point)subjects in design,the dependent variable for S2 twitch response to a target.The results show that the main effect of the cue type is significant,and the main effect of the experimental condition is not significant,so the results of experiment 3 show that the STD inhibition caused by the central fixation point does not affect the M task.To sum up,the following conclusions are drawn from this study :(1)the fixation point will affect the inhibition of return;(2)the reason that fixation point,which affects the input-based inhibition of return,is caused by the STD;(3)when saccadic to the periphera cues and targets will cause the input-and output-based inhibition of return,which support the two component theories;(4)STD does not affect the inhibition of return of all experimental conditions.