Novel Tools for Quantification of Brain Responses to Music Stimuli

Therapeutic effect of music is known for long time. Music therapy can be used to improve the current patient’s state or even prevent some deceases of psychosomatic origin. For decades, the basic research methods of music psychology mainly relied on survey with questionnaire or on observations of subjects. Investigating the effect of music through electroencephalograms (EEG) could be more precise and objective. In this paper, we describe fractal dimension model for quantification of brain responses to external stimuli. Human EEG evoked by music stimuli are analysed with the developed software. The proposed technique of processing EEG is based on the Renyi entropy — the concept of generalized entropy of a given probability distribution. It allows defining generalized fractal dimension of EEG. The experiments involved ten subjects, both male and female twenty years old university students. The EEGs were processed by the fractal dimension analysis tools. Analysis of fractal dimension values demonstrates that the method can be used to quantitatively distinguish between different states of the brain. Correlation between music, and subject’s emotion and concentration was studied. Few hypotheses were validated.