Characteristic Study On Event-related Potential Of Auditory Response From People With Absolute Pitch

Being a significant art form, music has many aesthetic values which haveattracted worldwide attention. A long experience in the field of music has positiveimpacts for the development of brain plasticity and cognitive function. People withmusical training have a special memory ability called absolute pitch. With thebooming development of electrophysiological study since1960s, a number of studieshave attempted to explore the mechanism of auditory response from people withabsolute pitch using EEG. However, there is still one key issue remained controversialwhich is whether working memory storage mode is called in the procedure of auditoryresponse from people with absolute pitch.In order to further discuss the above issue, this study has designed four groups ofexperiments using odd-ball paradigms on pure-tone stimulation response for twotypes of target groups respectively, which are people with musical training andabsolute pitch, and has also simultaneously recorded64leads EEG data for thesubjects and analyzed the characteristics of Event-Related Potential. Experiment1and2consist of two pure tones from sine waves and two with piano timbre; Experiment3and4consist of five pure tones with piano timbre and five with human voices consistof the same frequencies. In addition, Experiment4has adopted a ‘movable-doh’ modewhich respond the same audio stimulation with different musical alphabet. This studyhas introduced the time-frequency characteristic parameter: ERSP, thecharacterization parameter of complexity: wavelet entropy, and the method ofanalyzing cerebral information flow: Granger Causality analysis so as to extract andanalyze the characteristics for ERP of the auditory response from people with absolutepitch.In this study, the results of time domain analysis showed that in Experiment1and2, people with musical training had significantly shorter latency for their highersensitivity to auditory stimuli; And compared to the control group—people withrelative pitch, people with absolute pitch in Experiment3and4have produced P3with no significant difference in the influence of audio stimulation consisting of puretones, which indicate that the working memory update mode has been called in suchprocedure. And by using time-frequency characteristic analysis, it is discovered that in Experiment3, the cerebral multi-lead energy feature of people with absolute pitch inthe duration of400to600ms concentrated on13to18Hz with significant differencesfrom the control group, but such differences disappeared in Experiment4which showthat different experimental tasks could change the degree of usage in the encephalicregion for people with absolute pitch. In the wavelet entropy analysis, the waveletentropies of people with absolute pitch in the duration of400to600ms in Experiment3and4are significantly lower and higher than the control group respectively, whichindicate that the introduction of’movable-doh template’ has increased the complexityof absolute pitch in the brain. And in the Granger Causality analysis, the cerebralinformation flow from people with absolute pitch has notably lower density thanordinary people. The results of ERP characteristic analysis mentioned above canhopefully have a positive effect on providing the further insight into the physiologicalmechanism of absolute pitch.