| Repeated information is more likely to be perceived as more true,this is known as the illusory truth effect.Even worse,repeatedly correcting misinformation makes people believe it more,the backfire effect.This is because repeatedly correcting misinformation makes people more familiar with the recurring misinformation.Familiarity can arise from various sources,including repetition-induced familiarity,triggered by repeated exposure to a stimulus over a short period,and pre-existing familiarity,triggered by long-term life experience(e.g.,familiarity with a person’s face and back).However,previous research has focused on the effects of familiarity through repeated exposure,ignoring the reality of the individual’s pre-existing familiarity with the information.It is unclear whether these two sources of familiarity have different cognitive mechanisms and different effects on intervention approaches.The present study combined neuroscientific evidence to distinguish between two sources of familiarity,using four studies and a cognitive model(the drift-diffusion model)to verify the differences in cognitive mechanisms between the two types of familiarity and the different implications for interventions.The four studies were conducted based on the classical paradigm of the illusory truth effect.The paradigm consists of three phases: the presentation phase,the interference phase,and the judgment phase.In the presentation phase,participants were asked to rate their subjective familiarity with half of the information(40messages).The purpose of presenting some of the information before judging was to manipulate their familiarity with the information.In the interference phase,participants were asked to complete a task that was not relevant to the purpose of the experiment for5to10 minutes.In the judging phase,participants made a binary truthfulness judgment for all the information(80 messages,half from the presentation phase and half of the new information).The statements were half false and half true,and were balanced between old and new statements.All statements came from a Chinese online disinformation platform.Study 1 aimed to replicate the illusory truth effect and to investigate the impact of different sources of familiarity on this effect.To explore the relationship between processing fluency and familiarity,Study 2 used a reversed instruction in which participants were asked to judge whether the information was a rumor rather than whether it was true.Studies 3 and 4 implemented two common misinformation interventions.The presentation of information was followed by a warning(Study 3)and a debunking(Study 4)of the information’s truthfulness.Study 1 showed that both familiarities triggered by repetition and pre-existing familiarity induced an illusory truth effect,whereby familiar information was more often perceived as true.Moreover,both types of familiarity increased the speed of the participants’ judgments.Study 2 replicated these results but did not find an effect of the reversed instruction on either familiarity.To distinguish the cognitive mechanisms of the two familiarities,a cognitive modeling analysis of the behavioral data was conducted based on neuroscientific evidence.The analysis revealed that the two familiarities have different cognitive mechanisms for information veracity judgments.The familiarity caused by repetition mainly affected the degree of caution in judgment,i.e.,individuals tended to spend less time and obtained less evidence to make judgments for repeated statements.In contrast,the pre-existing familiarity mainly affected the process of accumulating evidence for information,i.e.,the more familiar the information was,the easier it was to obtain evidence of its truth.Study 3 found that the warning intervention eliminated judgment bias caused by repetition but did not suppress the effect of pre-existing familiarity or improve the correctness of individuals’ judgments.Study 4 found that the debunking intervention not only eliminated the effects of both familiarities,but also enhanced individuals’ ability to discriminate between misinformation.The model analysis further showed that the warning intervention had a similar effect on cognitive processes as repetition,reducing individuals’ decision caution.The debunking intervention,while not facilitating the process by which individuals accumulate informational evidence,could,to some extent,dampen the effects of pre-existing familiarity on evidence accumulation.These results suggest different effects of different interventions on familiarity across sources.The debunking approach outperforms the warning intervention in suppressing the truth effect arising from both types of familiarity.This study provides new insights into understanding the role of familiarity in veracity judgments.Drawing on the strengths of the cognitive model,this study distinguishes between the cognitive mechanisms of two different sources of familiarity.In particular,familiarity induced by experimentally manipulated repetition is effective in the short term and mainly influences the degree of caution in decision making.In contrast,pre-existing familiarity is related to life experience and has a long-term effect on decision making,mainly influencing the evidence accumulation process.In addition,this study reveals differences in the familiarity effect across interventions.The findings of this study have practical implications and provide an empirical basis for developing interventions and avoiding the effects of familiarity. |
