Language Development "By Ear"
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Two views of early
myelin formation in the
inferior coliculus (IC)
of the human fetus:
Left at 25, below at 29
gestational weeks.
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Early myelination of
other auditory nuclei
is also evident, in
the trapezoid body
(tzB) superior olive
(SOl), and lateral
lemniscus (LLm).
Pictures from Yakovlev
& Lecours (1967) with
permission from
Blackwell Scientific
Publishers.
|
The brainstem auditory system is
myelinated earlier than any other
system in the brain, and the human
fetus responds to sounds at 29
gestational weeks [72-74].
The language circuits of the temporal
and frontal lobes are not fully
myelinated until the third or fourth
postnatal year [72, 73].
Activity in the mature brainstem
auditory pathway would appear to
guide development of the cortical
language areas [75-77].
Thus children normally begin
speaking "by ear" before and during
maturation of the cortical language
areas.
Young children appear to hear syllable and
word boundaries more clearly than adults,
or even adolescents >>>
