Musical Training Enhances Automatic Encoding of Melodic Contour and Interval Structure

Abstract

Abstract& In music, melodic information is thought to be encoded in two forms, a contour code (up/down pattern of pitch changes) and an interval code (pitch distances between successive notes). A recent study recording the mismatch negativity (MMN) evoked by pitch contour and interval deviations in simple melodies demonstrated that people with no formal music education process both contour and interval information in the auditory cortex automatically. However, it is still unclear whether musical experience enhances both strategies of melodic encoding. We designed stimuli to examine contour and interval information separately. In the contour condition there were eight different standard melodies (presented on 80% of trials), each consisting of five notes all ascending in pitch, and the corresponding deviant melodies (20%) were altered to descending on their final note. The interval condition used one five-note standard melody transposed to eight keys from trial to trial, and on deviant trials the last note was raised by one whole tone without changing the pitch contour. There was also a control condition, in which a standard tone (990.7 Hz) and a deviant tone (1111.0 Hz) were presented. The magnetic counterpart of the MMN (MMNm) from musicians and nonmusicians was obtained as the difference between the dipole moment in response to the standard and deviant trials recorded by magnetoencephalography. Significantly larger MMNm was present in musicians in both contour and interval conditions than in nonmusicians, whereas MMNm in the control condition was similar for both groups. The interval MMNm was larger than the contour MMNm in musicians. No hemispheric difference was found in either group. The results suggest that musical training enhances the ability to automatically register abstract changes in the relative pitch structure of melodies. &

A mismatch negativity study of local–global auditory processing

“…Mismatch negativity has proven highly informative in assessing the automatic discrimination of both physical and abstract auditory properties, ranging from simple acoustic features such as the frequency, intensity or duration of pure tones (e.g., Novitski et al, 2004;Jaramillo et al, 2000;Paavilainen et al, 1991) to more complex musical or phonetic patterns (e.g., Fujioka et al, 2004;Näätänen et al, 1997;Paavilainen et al, 1999;Saarinen et al, 1992;Tervaniemi et al, 1994;van Zuijen et al, 2004van Zuijen et al, , 2005.…”

“…More recently, interval-contour stimuli have been used in MMN designs to further elucidate the neural underpinnings of melodic structural processing (e.g., Schiavetto et al, 1999;Trainor et al, 2002;Fujioka et al, 2004). In one such study (Schiavetto et al, 1999), only deviant contours (i.e., deviant "global" structures) reliably elicited MMN.…”

“…However, they did not report whether interval or contour manipulations alone revealed MMN in either the active or the passive tasks. Lastly, Fujioka et al (2004) compared passive structural processing of melodies in non-musicians vs. musicians, recording the magnetic MMN (mMMN). They aimed to determine whether musical expertise altered the neural indexing of musical structure.…”

“…1). Consequently, researchers employing interval-contour melodic variations have recently downplayed the mapping between melodic structure and local-global structure (e.g., Ayotte et al, 2000;Fujioka et al, 2004). This might indicate recognition of the failure for the interval-contour stimuli to adequately capture local-global perceptual structure.…”

Auditory attention to frequency and time: an analogy to visual local–global stimuli

“…For the different items, one tone of the melody is changed, either such that both interval and contour have been changed, or such that the interval on the scale has been disrupted but the contour preserved. These stimuli have been used extensively in behavioral studies (Peretz, 1987;Peretz & Morais, 1980, neuropsychological studies (Ayotte, Peretz, Rousseau, Bard, & Bojanowski, 2000;Liégeois-Chauvel, Peretz, Baba¿, Laguitton, & Chauvel, 1998;Peretz, 1990;Zatorre, 1985), and studies employing event-related potentials (Fujioka, Trainor, Ross, Kakigi, & Pantev, 2004;Schiavetto, Cortese, & Alain, 1999;Trainor, McDonald, & Alain, 2002), with at best mixed results regarding the proposed hemispheric asymmetry.…”