| With the rapid development of the Internet and information technology,the way individuals use media and engage with them is gradually changing.Compared to the past when people usually only deal with one single media,more and more people tend to engage in media multitasking.Working memory,as the core of human cognitive activities,is primarily responsible for the temporary storage and processing of information.In daily life,media multitasking,a way of using media,gradually affects people’s working memory.Therefore,studying the relationship between media multitasking and working memory has both great theoretical significance and rich practical value.However,there are still some limitations in current research on the relationship between the two.First,current research on the relationship between media multitasking and working memory has not yet reached a unified conclusion;second,most previous studies have not experimentally manipulated media multitasking and therefore cannot explore the causal effects of media multitasking on cognition;third,there is a relative lack of research on cognitive neural mechanisms.In order to make up for the shortcomings of previous studies,this present study will combine behavioral and cognitive neural evidence to systematically and comprehensively explore the impact of media multitasking types on working memory by conducting the following two main studies.Study 1 adapted the dual-task interference paradigm applied by Kazakova et al.(2015)and Ralph et al.(2020)in the study.The priming paradigm was used to manipulate media multitasking,and the N-back task was used to examine working memory.The differences in working memory between the simultaneous media multitasking group(n=26)and sequential media multitasking group(n=24)were investigated under different cognitive load levels.The results found that the simultaneous group performed significantly worse than the sequential group on working memory when the cognitive load was at the 1-back level on the accuracy and the sensitivity(d’),and the simultaneous group performed significantly worse than the sequential group on working memory when the cognitive load was at the 2-back level only on the accuracy,while there was no significant difference in the working memory performance of the two groups at the 3-back level on the accuracy and the sensitivity(d’).This suggests that media multitasking negatively affects working memory and is moderated by cognitive load.Study 2 repeated the experimental paradigm of Study 1,recruited 48 participants and randomly assigned them to the simultaneous media multitasking group(24)and the sequential media multitasking group(24),and examined behavioral differences in working memory performance between them.On this basis,EEG event-related potentials and neural oscillation indicators were examined.It was found that media multitasking type had a significant effect on working memory in terms of the behavioral indicators(accuracy,reaction time and d’),and that the simultaneous group all performed significantly worse than the sequential group,a result consistent with Study 1.In terms of ERPs metrics,the simultaneous media multitasking group had significantly greater latencies and significantly smaller wave amplitudes than the sequential group on the P2 component of the frontal area;at the 1-back level on the P3 component of the parietal area,the simultaneous and sequential groups differed significantly,and the sequential group had significantly greater mean wave amplitudes on the P3 component than the simultaneous group;at the 2-back level,the differences between the simultaneous and sequential groups were marginally significant.At the 3-back level,the differences between the simultaneous and sequential groups were not significant.In terms of EEG neural oscillations,the differences between the simultaneous and sequential groups were significant in frontal theta oscillations and marginally significant in parietal theta oscillations,both of which were less energetic in the simultaneous group than in the sequential group;there was no significant difference in parietal alpha oscillations.Our research has found that media multitasking would damage working memory,and this effect is moderated by cognitive load,mainly applicable to lower levels of cognitive load.The results support the sustained attention hypothesis,the theory of limited attention resources,and the perceptual load model,verify the cognitive impairment effect of media multitasking,expand the understanding of the causal direction of the relationship between media multitasking and working memory,and comprehensively reveal the effect and mechanism of media multitasking on working memory at both the behavioral and cognitive neural levels.Our research has implications for guiding correct media tasks and conducting interventions. |
