Different Processing Mechanisms Of Negative Compatibility Effects Under Relevant And Irrelevant Masking Condition

The negative compatibility effect(NCE)is a surprising phenomenon that the response to the target is faster and more accurate in incompatible trials than compatible trials.The NCE usually occurs at the unconscious level,which is an important part of the unconscious sensorimotor processing.The masked prime paradigm is usually used to explore the NCE,which is composed of the prime,mask,and target that appear sequentially.It was initially believed that the NCE was caused by the developmental process of activation-followed-by-inhibition of the response preparation induced by the prime(response inhibition hypothesis).Later researchers believed that the perceptual interaction between the prime and the mask used to intercept the representation of the prime is also the cause of the NCE(object updating hypothesis).According to the object updating hypothesis,the mask containing the characteristics of the primes(relevant mask)is the necessary condition for the NCE.However,a large number of studies have found that the mask that do not contain the characteristics of the primes(irrelevant mask)can also trigger the NCE,but there are differences in the size of NCEs between relevant and irrelevant masks conditions.For this reason,researchers began to pay attention to whether the processing mechanism of NCE under those two masks conditions is the same.Due to the potential factors of masking effectiveness,experimental paradigms,masking stimuli,and task relevance that have been mixed into the previous studies to discuss the above issue,no unified conclusion has been formed in the field at present.In addition,previous studies did not further investigate the occurrence of the NCE under the two masking conditions,such as the internal dynamic changes of the individual reaction process and brain activity,which will miss the key information in the processing of NCE under the two conditions.Therefore,this study adopted the digital masked prime paradigm,by introducing the response time distribution analysis method on the basis of the traditional behavioral data analysis method,with the help of Event-Related Potential(ERP)technology and functional magnetic resonance imaging(f MRI)technology,comparing the occurrence and development model of NCEs under the relevant and irrelevant masks conditions and the corresponding neural indicators,to clarify the different contributions of object updating and response inhibition in the generation of the NCE.The first research applied the reaction time distribution analysis method to investigate the dynamic change mode of the NCEs under the two masks conditions.Experiment 1 manipulated three within-subject variables of mask relevance,compatibility,and number of experiments(in order to strengthen the stimulus-response(S-R)link).It is found that the NCE with relevant mask can occur when the S-R link is weak and the reaction speed is faster;but the NCE with irrelevant mask condition can only appear when the S-R link is strong and the reaction speed is slow.It showed that the occurrence and change modes of the NCE under the two mask conditions were not the same.Experiment 2 added a 50 millisecond blank screen between the mask and the target to enhance the intensity of response inhibition,and further observed the development process of the NCEs under the two masks conditions,and found a similar result pattern to Experiment 1.After balancing the effect of the perceptual level,Experiment 3 examined the NCEs mode of the two masks conditions,and found that the result mode was unchanged.The first research proved that the processing mode of the NCEs with relevant and irrelevant masks were different from the behavioral level.The second research only used relevant mask to investigate whether the pure object updating is the root cause of the NCE with relevant mask.Experiment 4 used random lines that are not related to the target but can update the same or opposite target after interaction with mask as the primes.The effect of object updating on the NCE and its dynamic change model was studied when prime-induced response inhibition was excluded.As a result,a similar result pattern to Experiment 2 was found.Experiment 5adopted the paradigm of combining masked prime and Flanker task to investigate whether the processing pathways of object updating and response inhibition are the same in behavior.It was found that there was no interaction between the compatibility effect and the Flanker effect.The results of Study 2 showed that pure object updating plays a key role in the occurrence of the NCE with relevant mask,and there is a fundamental difference between object updating and response inhibition.The third research used ERP technology to investigate the development process of the NCEs with relevant and irrelevant masks under different S-R link strengths(weak before training and strong after training).The behavioral results still found that the NCE appeared before and after training under the relevant mask condition,while that under the irrelevant mask condition only appeared after training.In the ERP results,it was found that under the relevant mask condition,the compatible trials were more prone to activate the wrong response preparation in 260-310 milliseconds after the prime,and the occipital lobe Alpha oscillation energy was lower;under the irrelevant mask condition,the compatible trials were more prone to activate wrong response preparations in310-360 milliseconds after the prime,and the frontal central Theta oscillation energy was stronger.The third study proved that the processing mechanism of the NCEs with relevant and irrelevant mask is different from the level of ERP.The forth research used f MRI technology to further investigate the brain activation mode of the NCEs with relevant and irrelevant masks under different S-R link strengths.The whole-brain analysis showed that the NCE with relevant mask was related to the activities of the cuneus,middle and inferior occipital gyrus,fusiform gyrus,right middle temporal gyrus,and inferior frontal gyrus,whereas the NCE with irrelevant mask was related to the precuneus.The analysis of the region of interest found that under irrelevant mask condition,the blood oxygen level dependent(BOLD)signal of compatible trials was in the regions related to response inhibition such as supplementary motor area,basal ganglia(putamen,caudate,globus pallidus),thalamus,and regions related to conflict control such as the lateral prefrontal cortex were greater.However,under the relevant mask condition,there was no significant difference in the BOLD signal changes in the above regions between compatible and incompatible trials.The forth research revealed the different processing mechanisms of the NCEs with relevant and irrelevant mask from the level of brain imaging.In summary,this study proved that the NCEs with relevant and irrelevant masks have different processing mechanisms from the behavior,EEG,and brain imaging levels: the NCE with relevant mask is caused by object updating,which manifests as the response of the updated objects(caused by the perceptual interaction of the prime and the mask)was actived;while the NCE with irrelevant mask is caused by the response inhibition,which is manifested as the inhibition of the response of the prime.This study not only resolved the contradictions between the existing hypotheses about the NCE,but also advanced the understanding of the flexibility and diversity of the cognitive system in the process of unconscious sensorimotor information.