The Mechanism Of Negative Compatibility Effect In The Non-masked Priming Paradigm

It is an important method to study the impact of subliminal stimuli on behavior by masked priming paradigm. Generally compared with incompatible conditions, prime stimuli can promote the individual processing to target stimuli in compatible conditions. Since Eimer and Schlaghecken first discovered the counterintuitive negative compatibility effect, researchers have repeatedly prove the existence of a negative in masked priming paradigm. negative compatibility effect is a phenomenon that incompatible conditions have a shorter reaction and lower error than compatible conditions. Behavioral experiments, event-related potentials, functional magnetic resonance techniques, transcranial stimulation techniques have been used to study the mechanism and phase problems of the negative compatibility effect. Currently, there are four main theories to explain the mechanism of negative compatibility effect: self-inhibition hypothesis, object updating theory, mask-triggered inhibition theory and evaluation window account. Self-inhibition hypothesis put forward by Eimer and Schlaghecken is to point that negative compatibility effect is produced by a low and automatic suppression process. Only when prime stimuli have a low visibility and feeling characterization of that reaches a certain intensity can trigger the suppression process. Object updating theory proposed by Lleras and Enns think that negative compatibility effect stems from the sensory interaction between prime stimuli and masking stimuli. Mask-triggered inhibition theory proposed by Jas kowski also considered an inhibition mechanism. However, inhibition is evoked by masking stimuli which is presented after prime stimuli. Klauer and Dittrich assumed evaluation window account that evaluation window opens after starting stimulus presentation is a necessary condition to generate negative compatible effect. Differences between evaluation window account and three traditional theories are the phase problem and the issue if masking is a necessity to the negative compatible effect. That is to say, negative compatibility effect happens in the central phase or reaction stage, and this effect can be produced whether or not under non-masked prime condition. This study aimed to investigate:(1) whether the negative compatible effect, which is based on the central stage, can be produced in non-masked priming paradigm;(2) whether the two experiences, random and block, have different influence on negative compatible effect, which is emphasized by evaluation window account. To weaken the key link between stimulus and response, Chinese words were used as experimental material for this study. There were two experiments in this study as follows:32college students were tested in the first one.12pairs of Chinese words chosen from the Chinese emotional words system were used as experimental material. Individuals need to press the right key based on positivity or negativity of the target words. In this experiment, in order to examine in which condition can produce negative compatibility effect and when was the key ISI, ISI, consistency and stimulating presentation act as independent variables to be tested and reaction and error rate of the target words as dependent variables. Based on the first experiment, the second one had15college students and it had the same materials and individual task as the first one. Only consistency and stimulating presentation act as independent variables and reaction and error rate of the target words as dependent variables as well. With the LRP index and EEG, this experiment further examined the accuracy of prediction to negative compatibility effect by evaluation window account.There were several results in this study as follows: In experiment1, in the block condition it presented as shorter reaction under compatible condition when ISI is short. With the extension of ISI, the kind of advantage exhibited by compatible condition was decreasing and incompatible condition was beginning to show shorter reaction. When ISI reached470ms, the incompatible condition had a significant advantage. In the random condition, shorter reaction advantage in compatible condition existed throughout the whole ISI. As compared, incompatible condition had not revealed this kind of advantage from beginning to the end. In experiment2, behavioral results were similar to experiment1. Only block condition showed negative compatibility effect, reactions were still shorter under compatible condition in random condition. Similarly, an average LRP showed a weak positive wave under incompatible condition and a weak negative wave under compatible condition. And this kind of potential difference, which only represented under block condition, existed after the presentation of prime stimuli and before the presentation of target stimuli.Combined results and related discussions in experiment1and experiment2, the main conclusions of this study are as follows:Experiment1:Masking stimulus is not indispensable factor to produce negative compatibility effect. Priming paradigm without masking stimuli can also get negative compatibility effect. ISI between prime stimuli and target stimuli has a very important relationship to generate negative compatibility effect. Positive compatibility effect is showed when ISI is shorter and negative compatibility effect is showed when ISI is longer. Experience background formed by continuous stimulation flow and the size of negative compatibility effect is also closely linked. Negative compatibility effect only appears in block condition and positive compatibility effect appears in random condition.Experiment2:Incompatible conditions have exhibited advantages before the presentation of the target, which means predictions about the compatibility function pointed by evaluation window account need to be tested and modified. All the experiment results assume that negative compatibility effect, which is based on central stage, can be generated under non-mask condition. Two experiences, random and block, have different influence on negative compatibility effect, as the block condition is more likely to get a negative effect compatibility.