Early Right Anterior Negativity Research Articles

Relationship between schematic and dynamic expectations of melodic patterns in music perception

Prediction is fundamental in music listening. Two types of expectations have been proposed: schematic expectations, which arise from knowledge of tonal regularities (e.g., harmony and key) acquired through long-term plasticity and learning, and dynamic expectations, which arise from short-term regularity representations (e.g., rhythmic patterns and melodic contours) extracted from ongoing musical contexts. Although both expectations are indispensable in music listening, how they interact with each other in music prediction remains unclear. The present study examined the relationship between schematic and dynamic expectations in music processing using event-related potentials (ERPs). At the ending note of the melodies, the schematic expectation was violated by presenting a note with music-syntactic irregular (i.e., outof- key note), while the dynamic expectation was violated by presenting a contour deviant based on online statistical learning of melodic patterns. Schematic and dynamic expectations were manipulated to predict the same note. ERPs were recorded for the music-syntactic irregularity and the contour deviant, which occurred independently or simultaneously. The results showed that the music-syntactic irregularity elicited an early right anterior negativity (ERAN), reflecting the prediction error in the schematic expectation, while the contour deviant elicited a mismatch negativity (MMN), reflecting the prediction error in the dynamic expectation. Both components occurred within a similar latency range. Moreover, the ERP amplitude was multiplicatively increased when the irregularity and deviance occurred simultaneously. These findings suggest that schematic and dynamic expectations function concurrently in an interactive manner when both expectations predict the same note.

Does harmony function emerge from sequential notes in a diatonic mode? An event-related potential study

Harmony can be implied by scales in Western tonal music. This phenomenon has been named chord-scale theory in modern jazz practice. However, neurological evidence of such interaction remains unclear. Previous research utilized Event-Related Potentials (ERP), such as Early Right Anterior Negativity (ERAN) and N5, to study sound expectancy violations and the harmony integration process. The current study investigates whether sequential musical notes arranged in an ascending diatonic mode (1) violate the sound expectancy and (2) alter the harmonic function of the target chord. We designed a musical sequence, namely Prime A (chords) + Prime B (ascending scale notes) + Target (a chord). Prime A and B set up global and local tonality accordingly. We hypothesized that the processing of the target chord would be influenced by Prime B in the harmonic dimension. For instance, a Neapolitan sixth target chord (F, Ab, and Db) is incongruent under C Ionian but could be congruent with C Locrian or C Phrygian. We found ERAN and N5 amplitudes at the target chord are altered by (1) the implied harmonic degree of the local tonality and (2) the relative distance between the local and global tonality in the circle of the fifth space. Our results suggest that Western listeners' brains can interpret musical notes from diatonic mode as part of harmony processing and integrate them into complex tonal music contexts.

Tension experience induced by tonal and melodic shift at music phrase boundaries

Music tension is a link between music structures and emotions. As music unfolds, developmental patterns induce various emotional experiences, but the relationship between developmental patterns and tension experience remains unclear. The present study compared two developmental patterns of two successive phrases (tonal shift and melodic shift) with repetition condition to investigate the relationship with tension experience. Professional musicians rated on-line felt tension and EEG responses were recorded while listening to music sequences. Behavioral results showed that tension ratings under tonal and melodic shift conditions were higher than those under repetition conditions. ERP results showed larger potentials at early P300 and late positive component (LPC) time windows under tonal shift condition, and early right anterior negativity (ERAN) and LPC under melodic shift condition. ERSP results showed early beta and late gamma power increased under tonal shift condition, theta power decreased and alpha power increased under melodic shift condition. Our findings suggest that developmental patterns play a vital role in tension experiences; tonal shift affects tension by tonal shift detection and integration, while melodic shift affects tension by attentional processing and working memory integration. From the perspective of Event Structure Processing Model, solid evidence was given to specify the time-span segmentation and reduction.

Mapping Tonal Hierarchy in the Brain

In Western tonal music, pitches are organized hierarchically based on their perceived fit in a specific tonal context. This hierarchy forms scales that are commonly used in Western tonal music. The hierarchical nature of tonal structure is well established behaviourally; however, the neural underpinnings are largely unknown. In this study, EEG data and goodness-of-fit ratings were collected from 34 participants who listened to an arpeggio followed by a probe tone, where the probe tone could be any chromatic scale degree and the context any of the major keys. Goodness-of-fit ratings corresponded to the classic tonal hierarchy. N1, P2 and the Early Right Anterior Negativity (ERAN) were significantly modulated by scale degree. Furthermore, neural marker amplitudes and latencies were significantly correlated with similar magnitude to both pitch height and goodness-of-fit ratings. This is different from the clearer divide between pitch height correlating with early neural markers (100–200 ms) and tonal hierarchy correlating with late neural markers (200–1000 ms) reported by Sankaran et al. (2020) and Quiroga-Martinez et al. (2019). Finally, individual differences were greater than any main effects detected when pooling participants and brain-behavior correlations vary widely (i.e. r = −0.8 to 0.8).

The human brain processes hierarchical structures of meter and harmony differently: Evidence from musicians and nonmusicians.

The processing of temporal structure has been widely investigated, but evidence onhow the brain processes temporal and nontemporal structures simultaneously is sparse. Using event-related potentials (ERPs), we examined how the brain responds to temporal (metric) and nontemporal (harmonic) structures in music simultaneously, and whether these processes are impacted by musical expertise. Fifteen musicians and 15 nonmusicians rated the degree of completeness of musical sequences with or without violations in metric or harmonic structures. In the single violation conditions, the ERP results showed that both musicians and nonmusicians exhibited an early right anterior negativity (ERAN) as well as an N5 to temporal violations ("when"), and only an N5-like response to nontemporal violations ("what"), which were consistent with the behavioral results. In the double violation condition, however, only the ERP results, but not the behavioral results, revealed a significant interaction between temporal and nontemporal violations at a later integrative stage, as manifested by an enlarged N5 effect compared to the single violation conditions. These findings provide the first evidence that the human brain uses different neural mechanisms in processing metric and harmonic structures in music, which may shed light on how the brain generates predictions for "what" and "when" events in the natural environment.

Attention Modulates Electrophysiological Responses to Simultaneous Music and Language Syntax Processing.

Music and language are hypothesized to engage the same neural resources, particularly at the level of syntax processing. Recent reports suggest that attention modulates the shared processing of music and language, but the time-course of the effects of attention on music and language syntax processing are yet unclear. In this EEG study we vary top-down attention to language and music, while manipulating the syntactic structure of simultaneously presented musical chord progressions and garden-path sentences in a modified rapid serial visual presentation paradigm. The Early Right Anterior Negativity (ERAN) was observed in response to both attended and unattended musical syntax violations. In contrast, an N400 was only observed in response to attended linguistic syntax violations, and a P3/P600 only in response to attended musical syntax violations. Results suggest that early processing of musical syntax, as indexed by the ERAN, is relatively automatic; however, top-down allocation of attention changes the processing of syntax in both music and language at later stages of cognitive processing.

Dissonant endings of chord progressions elicit a larger ERAN than ambiguous endings in musicians.

In major-minor tonal music, the hierarchical relationships and patterns of tension/release are essential for its composition and experience. For most listeners, tension leads to an expectation of resolution. Thus, when musical expectations are broken, they are usually perceived as erroneous and elicit specific neural responses such as the early right anterior negativity (ERAN). In the present study, we explored if different degrees of musical violations are processed differently after long-term musical training in comparison to day-to-day exposure. We registered the ERPs elicited by listening to unexpected chords in both musicians and nonmusicians. More specifically, we compared the responses of strong violations by unexpected dissonant endings and mild violations by unexpected but consonant endings (Neapolitan chords). Our results show that, irrespective of training, irregular endings elicited the ERAN. However, the ERAN for dissonant endings was larger in musicians than in nonmusicians. More importantly, we observed a modulation of the neural responses by the degree of violation only in musicians. In this group, the amplitude of the ERAN was larger for strong than for mild violations. These results suggest an early sensitivity of musicians to dissonance, which is processed as less expected than tonal irregularities. We also found that irregular endings elicited a P3 only in musicians. Our study suggests that, even though violations of harmonic expectancies are detected by all listeners, musical training modulates how different violations of the musical context are processed.

Electrophysiological Correlates of Key and Harmony Processing in 3-year-old Children

Infants and children are able to track statistical regularities in perceptual input, which allows them to acquire structural aspects of language and music, such as syntax. However, much more is known about the development of linguistic compared to musical syntax. In the present study, we examined 3.5-year-olds’ implicit knowledge of Western musical pitch structure using electroencephalography (EEG). Event-related potentials (ERPs) were measured while children listened to chord sequences that either 1) followed Western harmony rules, 2) ended on a chord that went outside the key, or 3) ended on an in-key but less expected chord harmonically. Whereas adults tend to show an early right anterior negativity (ERAN) in response to unexpected chords (Koelsch, 2009), 3.5-year-olds in our study showed an immature response that was positive rather than negative in polarity. Our results suggest that very young children exhibit implicit knowledge of the pitch structure of Western music years before they have been shown to demonstrate that knowledge in behavioral tasks.

Effects of Visual Predictive Information and Sequential Context on Neural Processing of Musical Syntax.

The early right anterior negativity (ERAN) in event-related potentials (ERPs) is typically elicited by syntactically unexpected events in Western tonal music. We examined how visual predictive information influences syntactic processing, how musical or non-musical cues have different effects, and how they interact with sequential effects between trials, which could modulate with the strength of the sense of established tonality. The EEG was recorded from musicians who listened to chord sequences paired with one of four types of visual stimuli; two provided predictive information about the syntactic validity of the last chord through either musical notation of the whole sequence, or the word “regular” or “irregular,” while the other two, empty musical staves or a blank screen, provided no information. Half of the sequences ended with the syntactically invalid Neapolitan sixth chord, while the other half ended with the Tonic chord. Clear ERAN was observed in frontocentral electrodes in all conditions. A principal component analysis (PCA) was performed on the grand average response in the audio-only condition, to separate spatio-temporal dynamics of different scalp areas as principal components (PCs) and use them to extract auditory-related neural activities in the other visual-cue conditions. The first principal component (PC1) showed a symmetrical frontocentral topography, while the second (PC2) showed a right-lateralized frontal concentration. A source analysis confirmed the relative contribution of temporal sources to the former and a right frontal source to the latter. Cue predictability affected only the ERAN projected onto PC1, especially when the previous trial ended with the Tonic chord. The ERAN in PC2 was reduced in the trials following Neapolitan endings in general. However, the extent of this reduction differed between cue-styles, whereby it was nearly absent when musical notation was used, regardless of whether the staves were filled with notes or empty. The results suggest that the right frontal areas carry out the primary role in musical syntactic analysis and integration of the ongoing context, which produce schematic expectations that, together with the veridical expectation incorporated by the temporal areas, inform musical syntactic processing in musicians.

Differences in Neurocognitive Mechanisms Underlying the Processing of Center-Embedded and Non-embedded Musical Structures.

In music, chords are organized into hierarchical structures based on recursive or embedded syntax. How the brain extracts recursive grammar is a central question in musical cognition and other cognitive neuroscience, but the precise mechanism remains unclear. By analyzing event related potentials (ERPs) and neural oscillatory activity, the present study investigated neurocognitive mechanisms underlying the processing of center-embedded structure in music by examining the differences in center-embedded and non-embedded structure processing and evaluating how these differences are affected by musical proficiency. Based on Western musical proficiency, the subjects were divided into two groups, non-experts and experts. The results revealed that for non-experts, the processing of center-embedded structure elicited greater early right-anterior negativity (ERAN) and N5 components as well as, reduced alpha and gamma activities than did the non-embedded structure. For experts, no significant difference in the ERP response was observed between the processing of non-embedded and center-embedded structures; however, the processing of center-embedded structure elicited increased beta activity compared to non-embedded structure. These findings indicate that listeners different in proficiency would rely on different cognitive neural mechanisms in music processing with the syntactic complexity increases.

Syntactic processing in music and language: Effects of interrupting auditory streams with alternating timbres

Music and language both rely on the processing of spectral (pitch, timbre) and temporal (rhythm) information to create structure and meaning from incoming auditory streams. Behavioral results have shown that interrupting a melodic stream with unexpected changes in timbre leads to reduced syntactic processing. Such findings suggest that syntactic processing is conditional on successful streaming of incoming sequential information. The current study used event-related potentials (ERPs) to investigate whether (1) the effect of alternating timbres on syntactic processing is reflected in a reduced brain response to syntactic violations, and (2) the phenomenon is similar for music and language. Participants listened to melodies and sentences with either one timbre (piano or one voice) or three timbres (piano, guitar, and vibraphone, or three different voices). Half the stimuli contained syntactic violations: an out-of-key note in the melodies, and a phrase-structure violation in the sentences. We found smaller ERPs to syntactic violations in music in the three-timbre compared to the one-timbre condition, reflected in a reduced early right anterior negativity (ERAN). A similar but non-significant pattern was observed for language stimuli in both the early left anterior negativity (ELAN) and the left anterior negativity (LAN) ERPs. The results suggest that disruptions to auditory streaming may interfere with syntactic processing, especially for melodic sequences.

Syntactic processing in music and language: Parallel abnormalities observed in congenital amusia.

Evidence is accumulating that similar cognitive resources are engaged to process syntactic structure in music and language. Congenital amusia – a neurodevelopmental disorder that primarily affects music perception, including musical syntax – provides a special opportunity to understand the nature of this overlap. Using electroencephalography (EEG), we investigated whether individuals with congenital amusia have parallel deficits in processing language syntax in comparison to control participants. Twelve amusic participants (eight females) and 12 control participants (eight females) were presented melodies in one session, and spoken sentences in another session, both of which had syntactic-congruent and -incongruent stimuli. They were asked to complete a music-related and a language-related task that were irrelevant to the syntactic incongruities. Our results show that amusic participants exhibit impairments in the early stages of both music- and language-syntactic processing. Specifically, we found that two event-related potential (ERP) components – namely Early Right Anterior Negativity (ERAN) and Left Anterior Negativity (LAN), associated with music- and language-syntactic processing respectively, were absent in the amusia group. However, at later processing stages, amusics showed similar brain responses as controls to syntactic incongruities in both music and language. This was reflected in a normal N5 in response to melodies and a normal P600 to spoken sentences. Notably, amusics' parallel music- and language-syntactic impairments were not accompanied by deficits in semantic processing (indexed by normal N400 in response to semantic incongruities). Together, our findings provide further evidence for shared music and language syntactic processing, particularly at early stages of processing.

Musical Expectations Enhance Auditory Cortical Processing in Musicians: A Magnetoencephalography Study

The present study investigated the influence of musical expectations on auditory representations in musicians and non-musicians using magnetoencephalography (MEG). Neuroscientific studies have demonstrated that musical syntax is processed in the inferior frontal gyri, eliciting an early right anterior negativity (ERAN), and anatomical evidence has shown that interconnections occur between the frontal cortex and the belt and parabelt regions in the auditory cortex (AC). Therefore, we anticipated that musical expectations would mediate neural activities in the AC via an efferent pathway. To test this hypothesis, we measured the auditory-evoked fields (AEFs) of seven musicians and seven non-musicians while they were listening to a five-chord progression in which the expectancy of the third chord was manipulated (highly expected, less expected, and unexpected). The results revealed that highly expected chords elicited shorter N1m (negative AEF at approximately 100 ms) and P2m (positive AEF at approximately 200 ms) latencies and larger P2m amplitudes in the AC than less-expected and unexpected chords. The relations between P2m amplitudes/latencies and harmonic expectations were similar between the groups; however, musicians’ results were more remarkable than those of non-musicians. These findings suggest that auditory cortical processing is enhanced by musical knowledge and long-term training in a top-down manner, which is reflected in shortened N1m and P2m latencies and enhanced P2m amplitudes in the AC.

Musical training modulates the early but not the late stage of rhythmic syntactic processing.

Syntactic processing is essential for musical understanding. Although the processing of harmonic syntax has been well studied, very little is known about the neural mechanisms underlying rhythmic syntactic processing. The present study investigated the neural processing of rhythmic syntax and whether and to what extent long-term musical training impacts such processing. Fourteen musicians and 14 nonmusicians listened to syntactic-regular or syntactic-irregular rhythmic sequences and judged the completeness of these sequences. Nonmusicians, as well as musicians, showed a P600 effect to syntactic-irregular endings, indicating that musical exposure and perceptual learning of music are sufficient to enable nonmusicians to process rhythmic syntax at the late stage. However, musicians, but not nonmusicians, also exhibited an early right anterior negativity (ERAN) response to syntactic-irregular endings, which suggests that musical training only modulates the early but not the late stage of rhythmic syntactic processing. These findings revealed for the first time the neural mechanisms underlying the processing of rhythmic syntax in music, which has important implications for theories of hierarchically organized music cognition and comparative studies of syntactic processing in music and language.

Effects of veridical expectations on syntax processing in music: Event-related potential evidence.

Numerous past studies have investigated neurophysiological correlates of music-syntactic processing. However, only little is known about how prior knowledge about an upcoming syntactically irregular event modulates brain correlates of music-syntactic processing. Two versions of a short chord sequence were presented repeatedly to non-musicians (n = 20) and musicians (n = 20). One sequence version ended on a syntactically regular chord, and the other one ended on a syntactically irregular chord. Participants were either informed (cued condition), or not informed (non-cued condition) about whether the sequence would end on the regular or the irregular chord. Results indicate that in the cued condition (compared to the non-cued condition) the peak latency of the early right anterior negativity (ERAN), elicited by irregular chords, was earlier in both non-musicians and musicians. However, the expectations due to the knowledge about the upcoming event (veridical expectations) did not influence the amplitude of the ERAN. These results suggest that veridical expectations modulate only the speed, but not the principle mechanisms, of music-syntactic processing.

Affective versus cognitive responses to musical chords: An ERP and behavioral study.

When people listen to music, various brain processes are involved, including those that assess the rhythmic, tonal, timbral, and structural properties of the music-which we will call cognitive processing-as well as other processes, such as affective processing. Cognitive processing can, for example, allow us to implicitly notice when a note is out of key or out of rhythm by building a musical context out of the incoming sound stream. By affective processing, on the other hand, we refer to those brain processes that allow us to perceive or feel emotion in response to music, and to feel enjoyment of music or even find it beautiful. Only few studies on the processing of musical sounds have differentiated the psychological mechanisms underlying cognitive and affective processes (Gagnon & Peretz, 2000), as have some studies of other types of aesthetic stimuli, such as pictures (Mandler & Shebo, 1983). Even less is known about the brain correlates of those processes and their chronometric succession (e.g., see reviews by Brattico, Bogert, & Jacobsen, 2013; Jacobsen, 2006).Our current understanding of the information processing of music in the brain is mostly based on cognitive responses to musical sound patterns and chords, such as discrimination of sound feature changes or detection of tonality violations (for reviews, see the books by Koelsch [2012] and Peretz & Zatorre [2003]). A useful method to study the chronometric ordering of stages in auditory processing is the event-related potential (ERP), a neurophysiological signal elicited in response to a sensory or behavioral event, which comprises several components that are supposed to originate from distinct neuronal populations, (Luck, 2014). The ERP is measured by averaging time-accurate electroencephalogram (EEG) recordings over many trials of stimuli and across tens of participants. ERP studies have evidenced the early sensory encoding of sound features in the primary auditory cortex, as indexed by the N1 component, which peaks centrally at around 100 ms after stimulus onset (Naatanen & Picton, 1987). The subsequent stage of predictive coding and error detection (the error between predictions based on the regularities in the auditory stimulation and the incoming sound) is indexed by the mismatch negativity (MMN) component of the ERP, which is elicited by a feature change in a repeating stimulus sequence and peaks frontally around 150 to 200 ms after stimulus onset (Friston, 2005; Naatanen, Gaillard, & Mantysalo, 1978; Picton, Alain, Otten, Ritter, & Achim, 2000). The change can be simple, such as a sequence of identical tones being interrupted by a tone of a different frequency (Sams, Paavilainen, Alho, & Naatanen, 1985), or it can be more abstract, such as the violation of basic rules in tone patterns or combinations (e.g., the contrast between descending and ascending intervals: Saarinen, Paavilainen, Schoger, Tervaniemi, & Naatanen, 1992; or major and minor chords: Virtala et al., 2011).Cognitive processing of more complex rules involving an integration of sounds over longer time spans has been associated with the early right anterior negativity (ERAN), as well as the later P300. Similarly to the MMN, the ERAN peaks frontally around 200 ms after the onset of an unexpected musical sound; however, whereas the MMN is based on regularities between presently occurring successive sounds, the ERAN is a marker of unusual chord successions that depends on representations of harmonic regularities from long-term memory and can be caused by longdistance music-syntactic dependencies (Koelsch, Gunter, Friederici, & Schroger, 2000; Koelsch & Jentschke, 2010). A later ERP component related to chord processing is the P300, an endogenous, attentive response related to judgment of a stimulus (Squires, Squires, & Hillyard, 1975). The P300 peaks parietally 220 to 500 ms after the onset of a target tone in a discrimination task (Polich, 2007), of an incongruous tone presented at the end of a melody (e. …

Amygdala and orbitofrontal engagement in breach and resolution of expectancy: A case study.

Constant prediction is a process of future-directed information processing (Rohrmeier & Koelsch, 2012). It is a major factor of the interaction with the complexity of the human environment and contributes to updating of the so-called cognitive world model (Brown & Brune, 2012; Bubic, von Cramon, Jacobsen, Schroger, & Schubotz, 2009; Bubic, von Cramon, & Schubotz, 2010; Friston, 2012). The top-down prediction of what is likely to come next is advantageous, for example, for the preparation of fast adequate responses to incoming stimuli (Friston, 2009). In audition it enables the identification of incomplete, noisy, or ambiguous stimuli, the reduction of the orienting response (Huron, 2001; Summerfield & Egner, 2009), and the preparation of more accurate responses (Schultz, Dayan, & Montague, 1997). Predictions are essential for the organism, often resulting in punishment as a result of failures, and rewards for success. Reward and punishment is reflected in negative and positive affective reactions (Grossberg, 2009; Pearce & Wiggins, 2012).Several music studies have examined emotions associated with expectancy (e.g., Koelsch, Kilches, Steinbeis, & Schelinski, 2008; Salimpoor, Benovoy, Larcher, Dagher, & Zatorre, 2011; Steinbeis, Koelsch, & Sloboda, 2005). One central principle underlying the evocation of emotions with music relies in part on expectancy and prediction (Huron, 2006; Koelsch, 2014; Meyer, 1956). Using EEG, Flores-Gutierrez et al. (2007) found a lateralized frontal alpha suppression during listening to unpredictable music, perhaps originating in limbic/paralimbic structures. Using fMRI, it was found that breaches of expectancy evoke blood-oxygen level dependent (BOLD) changes in the amygdala (Koelsch, Fritz, & Schlaug, 2008) and the orbitofrontal cortex (OFC; Tillmann, Janata, & Bharucha, 2003; Koelsch, Fritz, Schulze, Alsop, & Schlaug, 2005). The emotional reaction to unexpected musical information was found to be reflected in increased electrodermal activity (Koelsch et al., 2008; Steinbeis et al., 2005). These regions play an important role in various emotional processes, including breaches of expectancy (Nobre, Coull, Frith, & Mesulam, 1999). Notably, the OFC is, in addition to numerous other affective functions, associated with the evaluation of the emotional significance of sensory stimuli (Rolls, 2000).In summary, limbic/paralimbic circuits including the OFC and the amygdala appear to be important for emotional reactions to expectancy violations in music. Psychologically, breaches of expectancy in music create not only surprise (Koelsch et al., 2008), but also modulate tension (Lehne, Rohrmeier, & Koelsch, 2014). In tonal music, a structural breach is usually followed by a transitory phase, which leads to the resolution of the breach; this transitory phase represents a delay of the expected resolution and relaxation (Koelsch, 2014). Note that the studies mentioned above only explored the breach of expectancy, and not the effects of the resolution of the resulting tension.Expectancy in music and its resulting tension is a process that occurs over time, and usually involves several discrete events. Koelsch (2014) proposed that the different factors giving rise to tension and resolution contribute to a tension arc, with the different factors underlying tension including the build-up of expectancy, its breach, anticipation of resolution, and resolution (with maximum tension during breaches of expectancies and the subsequent transitory phase).The cognitive processing of unexpected chords (i.e., cognitive aspects of irregularity detection) is neurophysiologically reflected in an early right anterior negativity (ERAN), which is mainly generated in inferior fronto-lateral (neo-)cortex (Lehne et al., 2014; Sammler et al., 2013). Thus, unexpected chords elicit both cognitive and emotional processes. As mentioned above, the emotion reactions to unexpected chords appear to be reflected, for example, in an increased activation of the amygdala (Koelsch et al. …

Attending to pitch information inhibits processing of pitch information: the curious case of amusia.

In normal listeners, the tonal rules of music guide musical expectancy. In a minority of individuals, known as amusics, the processing of tonality is disordered, which results in severe musical deficits. It has been shown that the tonal rules of music are neurally encoded, but not consciously available in amusics. Previous neurophysiological studies have not explicitly controlled the level of attention in tasks where participants ignored the tonal structure of the stimuli. Here, we test whether access to tonal knowledge can be demonstrated in congenital amusia when attention is controlled. Electric brain responses were recorded while asking participants to detect an individually adjusted near-threshold click in a melody. In half the melodies, a note was inserted that violated the tonal rules of music. In a second task, participants were presented with the same melodies but were required to detect the tonal deviation. Both tasks required sustained attention, thus conscious access to the rules of tonality was manipulated. In the click-detection task, the pitch deviants evoked an early right anterior negativity (ERAN) in both groups. In the pitch-detection task, the pitch deviants evoked an ERAN and P600 in controls but not in amusics. These results indicate that pitch regularities are represented in the cortex of amusics, but are not consciously available. Moreover, performing a pitch-judgment task eliminated the ERAN in amusics, suggesting that attending to pitch information interferes with perception of pitch. We propose that an impaired top-down frontotemporal projection is responsible for this disorder.

The Mismatch Negativity: An Indicator of Perception of Regularities in Music.

This paper reviews music research using Mismatch Negativity (MMN). MMN is a deviation-specific component of auditory event-related potential (EPR), which detects a deviation between a sound and an internal representation (e.g., memory trace). Recent studies have expanded the notion and the paradigms of MMN to higher-order music processing such as those involving short melodies, harmony chord, and music syntax. In this vein, we firstly reviewed the evolution of MMN from sound to music and then mainly compared the differences of MMN features between musicians and nonmusicians, followed by the discussion of the potential roles of the training effect and the natural exposure in MMN. Since MMN can serve as an index of neural plasticity, it thus can be widely used in clinical and other applied areas, such as detecting music preference in newborns or assessing wholeness of central auditory system of hearing illness. Finally, we pointed out some open questions and further directions. Current music perception research using MMN has mainly focused on relatively low hierarchical structure of music perception. To fully understand the neural substrates underlying processing of regularities in music, it is important and beneficial to combine MMN with other experimental paradigms such as early right-anterior negativity (ERAN).

Electrophysiological evidence for a specific neural correlate of musical violation expectation in primary-school children

The majority of studies on music processing in children used simple musical stimuli. Here, primary schoolchildren judged the appropriateness of musical closure in expressive polyphone music, while high-density electroencephalography was recorded. Stimuli ended either regularly or contained refined in-key harmonic transgressions at closure. The children discriminated the transgressions well above chance. Regular and transgressed endings evoked opposite scalp voltage configurations peaking around 400ms after stimulus onset with bilateral frontal negativity for regular and centro-posterior negativity (CPN) for transgressed endings. A positive correlation could be established between strength of the CPN response and rater sensitivity (d-prime). We also investigated whether the capacity to discriminate the transgressions was supported by auditory domain specific or general cognitive mechanisms, and found that working memory capacity predicted transgression discrimination. Latency and distribution of the CPN are reminiscent of the N400, typically observed in response to semantic incongruities in language. Therefore our observation is intriguing, as the CPN occurred here within an intra-musical context, without any symbols referring to the external world. Moreover, the harmonic in-key transgressions that we implemented may be considered syntactical as they transgress structural rules. Such structural incongruities in music are typically followed by an early right anterior negativity (ERAN) and an N5, but not so here. Putative contributive sources of the CPN were localized in left pre-motor, mid-posterior cingulate and superior parietal regions of the brain that can be linked to integration processing. These results suggest that, at least in children, processing of syntax and meaning may coincide in complex intra-musical contexts.