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

General Discussion 167
Methodological considerations: The use of additional evaluation methods might enable
to gain further insight from the present data. Firstly, the analysis of frequency character-
istics may provide additional knowledge of which kind of cognitive processes contribute
to the processing of musical and linguistic syntax and if these processes differ between
the groups of participants. The basic assumption is that particular classes of cognitive
processes are related to certain frequency signatures. Recently, there are – to my
knowledge – no studies that investigated the frequency characteristics of syntactic processing
in music and language. However, such evaluation would have been beyond the
scope of the present work. Profound knowledge about which cognitive processes can be
related to a particular frequency signature is needed for a proficient interpretation of
such data. A second method, coupling measures might enhance our understanding of
which brain regions interact in which ways when musical and linguistic syntax are
processed. However, since these coupling measures are based on relations between the
scalp electrodes, they provide rather crude information about the localization of these
processes. Only a limited number of electrodes were used in the experiments of the
present work, since technical and practical limitations of the current measurement
equipment did not allow for acquiring measurements from a larger number of electrodes.
Thus, source localisation will not be possible. Finally, the scalp distribution of
most of the ERP components that were investigated in this study was rather broad. The
computations of surface Laplacian transformations (it is a measure current source density
on the scalp obtained with spline functions) may help to specify more exactly the
scalp site where these ERP responses are strongest.
Theoretical issues: Even though the present data allow for determining at which age
first signs of processing musical syntax become established, this does not allow to investigate
on which other basic processes these are grounded and how these processes
become established. That is, currently it is not clear which processing stages are a prerequisite
for the acquisition of music-syntactic regularities. For example, it is currently
not known if it is necessary to extract the key in order to have a referential system, or if
the acquisition of music-syntactic regularities might also take place on the basis of the
computation of frequency relations between succeeding tones or chords. Such topics
might be investigated using, e.g., MMN paradigms (Brattico et al., 2006; Fujioka et al.,
2005) or modelling of these processes in neural networks (Bharucha, 1987; Tillmann et
al., 2000).
Utilizing the knowledge gathered from this work: The results of the Experiments in this
work demonstrate the strong relation between music and language: Both, the lack of
ERP correlates of music-syntactic processing in the 5-year old children with SLI as well
as the finding of an improved processing of both musical and linguistic syntax in the 11-