Research On The Effects Of Background Music On Working Memory Based On Granger Causal Network

Music is a medium for people to convey information and express their feelings,and it has a great influence on the cognitive activities.Some studies show that music has a positive effect on memory,while others show that music has a negative effect on memory.Therefore,it is of great significance to study the influence of background music on working memory.In this thesis,the improved Sternberg working memory task experiment was designed,20 subjects were selected to participate in the experiment,the EEG data of the subjects in remembering English words in three states(without music,classical music and rock music)were collected,and the behavioral data were recorded at the same time.After the pre-processing and analysis of the EEG data and behavioral data,the directional transfer function(DTF)values between the channels were calculated by using the frequency domain Granger causality analysis method.Based on the DTF matrix of the subjects in three states,the causal network between the whole brain area and the inner brain area were constructed in alpha band and beta band.Finally,the characteristic attributes of causal network were analyzed to explore the influence of different background music on working memory.The results show that the DTF values of brain network in the state of classical music and rock music are smaller than those in the state without music,and the DTF values in the state of rock music are smaller than those in the state of classical music.The effective connections of brain network in the state of classical music and rock music are less than those in the state without music,and the connections of frontal,central and parietal areas are less.Similarly,compared with the state without music,the node degree,access degree,global efficiency and connection density of classical music and rock music state are all reduced,which also shows that the causal connection strength between nodes in the brain network decreases,and the efficiency of information transmission decreases.The results of behavioral data show that the correct response rates of the subjects under no music stimulation,classical music state and rock music state are about 91%,86% and 80%,respectively,and the average response times under three states are 728 ms,761 ms and 818 ms,respectively.It can be seen that the musical stimulations reduce the correct response rates of the subjects and increase the response times,which indicate that the musical stimulations interfere with the working memory.