Music And The Brain
The long supposed connection between mind and music has been further demonstrated by an international collaboration of physicists led by Simone Bianco and Paolo Grigolini at the Center for Nonlinear Science at the University of North Texas. A statistical analysis reveals a remarkable similarity between the distributions produced by music compositions and brain activity.
Brain activity was monitored through an electroencephalograph (EEG), which records electrical signals on the surface of the brain. The musical compositions were analyzed based on the melody, harmony, rhythm, pitch, and timber among other factors.
Researchers mapped brain activity and the compositions by regions of similarity punctuated by jumps where a significant change occurred. The data illustrated the similarity between patterns of electrical signals in the brain and of musical compositions.
In addition, the team determined a complexity index for the compositions and brain function, a number to describe the intricacy of either the musical patterns or electrical signals. The complexity indices for both patterns were less than two. This suggests that both the brain and the composition are self-organized, but in the case of the composition, it probably reflects the self-organized mind of the composer. The interpretation of the complexity index remains a question for further research.
In future experiments, researchers will monitor the brain activity of participants who are listening to music. This study will assess whether the complexity of a participant’s brain activity is affected by the complexity of the composition. In addition, they will seek “fits” where the complexity of the music resembles the brain activity of the listener. If the physcists’ hypothesis is correct, the fit between a composition and your brain activity helps determine your musical preferences
Authors: Simone Bianco, Massimiliano Ignaccolo, Mark S. Rider, Mary J. Ross, Phil Winsor, Paolo Grigolini
(Submitted on 19 Oct 2006 (v1), last revised 16 Mar 2007 (this version, v3))
Abstract: In this paper we show that both music composition and brain function, as revealed by the Electroencephalogram (EEG) analysis, are renewal non-Poisson processes living in the non-ergodic dominion. To reach this important conclusion we process the data with the minimum spanning tree method, so as to detect significant events, thereby building a sequence of times, which is the time series to analyze. Then we show that in both cases, EEG and music composition, these significant events are the signature of a non-Poisson renewal process. This conclusion is reached using a techniques of statistical analysis recently developed by our group, the Aging Experiment (AE). First, we find that in both cases the distances between two consecutive events are described by non-exponential histograms, thereby proving the non-Poisson nature of these processes. The corresponding survival probabilities $\Psi(t)$ are well fitted by stretched exponentials ($\Psi(t) \propto exp(-(\gamma t)^\alpha$), with $0.5