Neural Correlates of Processing Syntax in Music and ... - PubMan

Music Perception 18
tial extent of activation in the STG in global- and selective-listening conditions whereas
parietal (intraparietal sulcus and frontal operculum) and medial frontal structures (infe-
rior frontal sulcus, precentral sulcus and pre-SMA) were more active when selectively
attending to one stream.
Structure building: The analysis of musical structure requires the computation of
structural relations, e.g., that of the relation between a chord function and a preceding
harmonic context. Similar operations presumably exist for the processing of rhythm and
metre. Most of these processes appear to be fairly automatic (Koelsch, 2005). Two
processes may be detrimental for the processing of musical syntax: Inducing tonality
and building up harmonic relations.
Tonality induction: Pitches are organized along musical scales around a central tone
(the tonic) and with a hierarchy of importance of the remaining scale tones (with the
fifth and the third scale tone closely related to the tonic). The relations of succeeding
pitches do not only define interval size but also evoke a particular scale. Thus, the tonal
system mediates perception of musical pitch in an automatic way and without conscious
awareness (cf. Tillmann et al., 2000). The brain structures maintaining tonal knowledge
are proposed to reside largely outside of temporal lobe auditory structures (Tramo, Bharucha,
& Musiek, 1990). Zatorre (2001) suggested a hierarchical view, with right inferior
lateral frontal areas that are important for maintenance of tonal information, and
dorsolateral frontal areas that are involved in higher-level functions such as monitoring
the contents of working memory. Janata et al. (2002) demonstrated that areas in the
rostro-medial prefrontal cortex track activation in tonal space and exhibited selectivity
for different keys. These brain regions are assumed to underlie the processing of the
formal structure that determines relationships within a harmonic or tonal space on which
Western tonal music relies.
Harmonic relations: Music unfolds over long periods of time and is highly structured
along multiple dimensions. Its processing involves the contribution of different sources
of knowledge. Music-syntactic processing requires the processing of long-distance
dependencies which may be crucially dependent of the contribution of working memory.
The perception of pitch relations in chords seems to operate like the perception of
the tonal hierarchy among successive tones. The succession of chords is governed by
harmonic principles, whose regularities are assimilated via passive exposure to samples
of Western music (Bigand, 2003; Tillmann et al., 2000). A number of studies focused
on working memory for tonal information. They converge on the idea that it may rely
on interactions between frontal cortical and posterior temporal areas (Griffiths et al.,
1999; Zatorre, Evans, & Meyer, 1994).