Basic and Clinical October 2014 . Volume 5. Number 4 Neural Correlates of Boredom in Music Perception Ashkan Fakhr Tabatabaie1, Mohammad Reza Azadehfar 1, Negin Mirian 2, Maryam Noroozian 3,4, Ahmad Yoonessi 5, Mohammad Reza Saebipour 6, Ali Yoonessi 7, 8* 1. Department of Music, Faculty of Music, Tehran University of Art, Tehran, Iran. 2. Department of Biostatistics, Faculty of Statistics, Shahrekord University of Medical Sciences, Shahrekod, Iran. 3. Department of Memory and Behavioral Neurology, Roozbeh Hospital, Tehran, Iran. 4. Department of Memory and Behavioral Neurology, Faculty of Psychiatry, Tehran University of Medical Sciences, Tehran, Iran. 5. McGill Vision Research Center, McGill University, Montreal, Canada. 6. Department of Neuroscience, School of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran. 7. Department of Neuroscience, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran. 8. National Brain Mapping Centre, Tehran, Iran. Article info: A B S T R A C T Received: 11 February 2014 First Revision: 29 April 2014 Introduction: Music can elicit powerful emotional responses, the neural correlates of which Accepted: 5 August 2014 have not been properly understood. An important aspect about the quality of any musical piece is its ability to elicit a sense of excitement in the listeners. In this study, we investigated the neural correlates of boredom evoked by music in human subjects. Methods: We used EEG recording in nine subjects while they were listening to total number of 10 short-length (83 sec) musical pieces with various boredom indices. Subjects evaluated boringness of musical pieces while their EEG was recording. Results: Using short time Fourier analysis, we found that beta 2 rhythm was (16-20 Hz) Key Words: significantly lower whenever the subjects rated the music as boring in comparison to non- boring. Music, Emotion, Boredom, EEG, Discussion: The results demonstrate that the music modulates neural activity of various parts Brain rhythms of the brain and can be measured using EEG. 1. Introduction emotional response can lead to higher sense of enjoy- ment from the musical piece. This emotional excitement usic and its effect on human perception can lead to increase in intelligence (Schellenberg, 2005), has been a mystery for centuries. While better psychological mood (Särkämö et al., 2008), and serving different roles in human evolu- reduction in depression and anxiety (Castillo-Pérez, Gó- tion and development, societies from mez-Pérez, Velasco, Pérez-Campos, & Mayoral, 2010; M every part of the world have produced Mok & Wong, 2003; Salamon, Bernstein, Kim, Kim, and performed highly diverse music, in & Stefano, 2003). Thus, maximizing the emotional en- addition, the richness of general cognitive mechanisms joyment from a musical piece is not only important for involved in these musical activities makes them ideal musicians aiming to improve the influence of their com- sources of investigation so early in cognitive science position and performance, but also can have important (Pearce & Rohrmeier, 2012). clinical implications. Furthermore, any Human-comput- er interface (HCI) can benefit significantly from modula- An important part of any musical piece is its ability tion of the emotional state of the user. to modulate the audience’s mood, and evoke powerful emotional responses. Increasing the magnitude of this * Corresponding Author: Ali Yoonessi, MD, PhD Address: School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, No. 88, Italy Avenue, Tehran, Iran. Tel.: +98 (131) 6690099 / Fax: +98 (131) 6690036 E-mail: [email protected]. 259 October 2014 . Volume 5. Number 4 Brain imaging techniques make it possible to attain par- dynamic, existential, arousal and cognitive theories. ticularly useful information about the implied emotional Generally, it is described as an unpleasant state in which and cognitive contents of a musical piece directly. Neural one desires to engage in a satisfying activity but this correlates of pleasant and unpleasant feelings have been would be not possible whether because of individual or studied using electroencephalography (EEG) (Field et environmental impairments (Eastwood, Frischen, Fen- al., 1997; Schmidt & Trainor, 2001), positron emission ske & Smilek, 2012). In this study we employed the term tomography (PET) (Blood, Zatorre, Bermudez, & Evans, boredom in a manner consistent with this definition. Be- 1999; Blood & Zatorre, 2001), and functional magnetic sides, the meaning of boredom is interestingly connected resonance imaging (fMRI) (Koelsch, Fritz, Cramon, to attention; they are not identical but they have been Müller & Friederici, 2006). Combination of these tech- shown to be closely correlated (Eastwood et al., 2012). niques (fMRI and EEG) have shown further correlations between responses of pleasant and unpleasant musical Dorso-Lateral Prefrontal Cortex (DLPFC) area has emotions (Flores-Gutiérrez et al., 2007). These studies been demonstrated to be involved in numerous studies demonstrate the possibility of differentiating neural cor- of attention deficit hyperactivity disorder (ADHD) (Bur- relates of generic pleasant and unpleasant feelings. gess et al., 2010; Passarotti, Sweeney, & Pavuluri, 2010), drug craving (Fregni et al., 2008; Wilson, Sayette & EEG has several important characteristics that make Fiez, 2004) and obsessive-compulsive disorder (OCD) it ideal to record such correlations between neural and (Atmaca, 2013; Russell et al., 2003). Therefore, we sug- emotional responses. EEG can be recorded in any loca- gest that this region might be important in modulation of tion in natural body conditions, whereas techniques such boredom as well as attention, and we should see similar as fMRI can only be recorded in specific locations, with brain indices for them here. However, even though DLP- the addition of evoked emotions from claustrophobia FC has been shown to be extremely important in many and scanner noise. Other techniques such as PET face cognitive tasks, to our knowledge, its importance in mu- similar problems with the addition of hazards from ra- sic perception has not been studied using EEG so far. In dioactive materials. Furthermore, recording EEG signals this study, we examined the changes of brain rhythms is extremely low cost in comparison to fMRI and PET including theta, alpha, and beta (low, mid and high) from and can be performed using minimal instruments. In re- EEG in this region in response to music pieces. cent years, the commercial costs of EEG systems that can be used without specific knowledge of EEG by the user In this study, we employed EEG to investigate the neural have been reduced. Additionally, due to the high tempo- correlates of subjective sense of boredom provoked by mu- ral resolution of EEG, it is possible to study brain pro- sic. Several pieces of music that were pre-rated by a group cesses at various time scales and frequency bands. The of subjects as boring or non-boring were employed. Most activity in these frequency bands can be easily correlated of the boring pieces contained a specific repetitive melodic with mental functions and evoked emotions (Mantini, phrase. These melodic phrases were repeated continuously Perrucci, Del Gratta, Romani, & Corbetta, 2007). thorough the pieces with or without variation in every cy- cle. Conversely, the non-boring pieces were chosen from Studies using the EEG recordings while listening to mu- exciting music compositions. During the EEG session, hu- sic, have shown a decrease in alpha and theta power well man subjects were instructed to respond whenever they felt defined in the temporal area of the left hemisphere, in com- the pieces were boring. The pieces, which were not report- parison with resting state (Petsche, Linder, Rappelsberger, ed by subjects as boring, were employed as controls. The & Gruber, 1988), a decrease in alpha and an increase in frequency responses of the EEG recordings were analyzed theta total power in comparison with listening to nonmusi- using Fourier transform. We analyzed the power spectrum cal sounds (Ramos & Corsi-Cabrera, 1989; Yuan, Liu, Li, of responses in each frequency band. Wang, & Liu, 2000). Moreover, the pleasant music com- pared to unpleasant music has been shown to be positively 2. Methods associated with total theta (Kabuto, Kageyama, & Nitta, 1993), and frontal midline theta (Sammler, Grigutsch, Fritz 2.1. Subjects & Koelsch, 2007a) power changes. Nine healthy subjects with the age range of 22 to 30 However, while emotional excitement from a piece of (5 Male, Six right-handed, Mean age=26.7 ± 2.5) par- music is extremely important, the neural correlates of ticipated voluntarily in this study. The sample size was sense of boredom have been poorly understood. Bore- estimated using PASS 13 (NCSS, LLC) software, with dom has been subject of various definitions by psycho- actual power of 0.8 (Liu and Wu, 2005). Case selection 260 Basic and Clinical October 2014 . Volume 5. Number 4 was based on available cases. All subjects signed an IRB shown in Figure 1 A, C. The average number of repeti- approved informed consent form, which was provided by tive melodic cycles within all the boring pieces, which ethic board of ICSS (Iran Institute of Cognitive Science hold repetitive melodic phrases, was 30.8 ± 15.5. These Studies). Subjects were unaware to the purpose of the ex- pieces were sufficiently different to explore a large range periment and