Automatic Encoding of Polyphonic Melodies in Musicians and Nonmusicians

Abstract

Abstract& In music, multiple musical objects often overlap in time. Western polyphonic music contains multiple simultaneous melodic lines (referred to as ''voices'') of equal importance. Previous electrophysiological studies have shown that pitch changes in a single melody are automatically encoded in memory traces, as indexed by mismatch negativity (MMN) and its magnetic counterpart (MMNm), and that this encoding process is enhanced by musical experience. In the present study, we examined whether two simultaneous melodies in polyphonic music are represented as separate entities in the auditory memory trace. Musicians and untrained controls were tested in both magnetoencephalogram and behavioral sessions. Polyphonic stimuli were created by combining two melodies (A and B), each consisting of the same five notes but in a different order. Melody A was in the high voice and Melody B in the low voice in one condition, and this was reversed in the other condition. On 50% of trials, a deviant final (5th) note was played either in the high or in the low voice, and it either went outside the key of the melody or remained within the key. These four deviations occurred with equal probability of 12.5% each. Clear MMNm was obtained for most changes in both groups, despite the 50% deviance level, with a larger amplitude in musicians than in controls. The response pattern was consistent across groups, with larger MMNm for deviants in the high voice than in the low voice, and larger MMNm for in-key than out-of-key changes, despite better behavioral performance for out-of-key changes. The results suggest that melodic information in each voice in polyphonic music is encoded in the sensory memory trace, that the higher voice is more salient than the lower, and that tonality may be processed primarily at cognitive stages subsequent to MMN generation. &

Selective Subcortical Enhancement of Musical Intervals in Musicians

“…Musicians have also been found to have more enhanced MMNm than nonmusicians. This has been attributed to cortical reorganization resulting from long-term training because the source of MMN is located mainly in the auditory cortex (Fujioka et al, 2005). Our study is the first to show that this upper tone dominance at the cortical level extends to the subcortical sensory system.…”

“…For example, behavioral studies have shown that changes occurring in the upper voice are more easily detected than those in the middle or lower voice (Palmer and Holleran, 1994;Crawley et al, 2002). Furthermore, electrophysiological studies showed larger and earlier mismatch negativity magnetic field (MMNm) responses for deviations in the upper voice melody than in the lower voice (Fujioka et al, 2005(Fujioka et al, , 2008. Musicians have also been found to have more enhanced MMNm than nonmusicians.…”

Dynamics of brain activity underlying working memory for music in a naturalistic condition

“…For instance, we might see not also differences in asymmetry across groups for WM, but also within groups across different conditions, i.e., due to different levels of complexity in the music. For instance, although musicians tend to rely on left-sided brain for music processing in a greater extent than non-musicians (Fujioka, Trainor, Ross, Kakigi, & Pantev, 2005), possibly explained by a more consciously learned or analytic approach to the musical input, complex music has been reported to drive even trained musicians into strongly using their 'right brain' (Vollmer-Haase, Finke, Hartje, & Bulla-Hellwig, 1998;McGilchrist, 2010).…”

Rhythm judgments reveal a frequency asymmetry in the perception and neural coding of sound synchrony

“…A series of recent studies has suggested that these and other basic properties of the auditory system, which are shared by a wide variety of species, may help account for some fundamental aspects of Western music, including the dominance of high-register instruments (i.e., instruments with high fundamental frequencies) in carrying the melody (3)(4)(5)(6)(7), as well as the dominance of low-register instruments (such as bass or bass drum) in defining the meter or rhythm (8). In the latter case, a study by Hove et al (8) involving both behavioral and EEG experiments reported that time encoding was superior for low-vs. high-pitched sounds and suggested that this superior time encoding could explain why low instruments generally lay the rhythm in music.…”