Rie Asano
From theoretical as well as empirical perspectives, there is an increasing number of evidences
for a close relationship between language syntax and musical rhythm (e.g., Fitch, 2013; Gordon
et al., 2015), although this link seems not to be intuitive and tends to be neglected so far. In the
current paper, based on the findings of cognitive neuroscience (e.g., Kotz et al., 2009), I indeed
argue for the strong link between language syntax and musical rhythm by showing that the same
neurocognitive mechanisms implemented in the cortico-basal ganglia-thalamocortical (CBGT)
circuits are involved in and necessary for flexible motor and cognitive control crucial for both
domains.
The basal ganglia are known to contribute as a ‘control center’ working together with
the cortico-thalamic pattern generators in both motor and cognitive domains: 1) assisting
execution of cortically driven predictable and automatic motor and cognitive patterns; and 2)
adapting to unusual circumstances by interrupting and altering the automatically running motor
and cognitive representations (Graybiel, 1997; Marsden & Obeso, 1994). Those dual functions
of the basal ganglia facilitate flexibility and adaptation in motor and cognitive control. Indeed,
motor and cognitive flexibility is crucial for processing musical rhythm and language syntax.
Goal-directed, reward-based adaptation in motor control through the basal ganglia is
wide-spread in animals. However, mice with humanized Foxp2 shows change in the basal
ganglia (increase in total dendrite length of the striatal medium spiny neurons) and significantly
more rapid switching of their behavioral strategy (Enard, 2011; Scharff & Petri, 2011;
Schreiweis et al., 2014). Further, between-species difference in dopaminergic innervation of
the caudate is reported (Raghanti et al., 2016). Thus, I claim that phylogenetic changes in the
CBGT circuits led to increasingly more flexible motor and cognitive control in humans, making
the brain partly ready for processing musical rhythm and language syntax.
References
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