overlapping auditory and parietal association cortices for reception and
interpretation,and partly overlapping motor and premotor cortices for
production.Each has a recently discovered input from the cerebellum.
Music and language can both be produced by mouths or by tools,and
each is processed somewhat differently by men and women.Each activ-
ity engages a frontal lobe-mediated ability to keep ideas in mind long
enough to bring them to fruition,and recruits additional areas of tem-
poral and parietal cortices for longer retention.Finally,humans are able
both to speak and to hear music in their heads.
Fewer differences than similarities exist between the neurological pro-
cessing of music and language.One can think of the two activities as
simply being broadcast by different television or radio channels.For
example,one may tune to the music channel (MTV on the author’s tele-
vision,mostly the right hemisphere in her brain) for sounds that com-
municate emotions in a holistic manner.Change to the Learning Channel
(mostly the left hemisphere),and one is likely to receive a language
lesson that involves analyzing sequences of referential sounds that com-
municate specific bits of meaning.One other remarkable difference dis-
tinguishes musical from linguistic processing:as a species,humans are
generally better at listening to music than at composing it,which is left
to specialists.Even many musicians seem content to perform other
people’s compositions.This is obviously not true for language,in which
all normal people actively and continually compose and perform.Since
people are universally more adept at language than at music,it is
tempting to speculate that the former was a direct target of natural selec-
tion,whereas the latter went along for the ride (Finlay and Darlington
1995).
Be that as it may,because music and language are so neurologically
intertwined,it is reasonable to speculate that they evolved together as
brain size increased during the past two million years of evolution of the
genus Homo.Therefore,if we can pinpoint the time by which language
originated,we probably know when music did.The relevant paleoneu-
rological data are these.By about two million years ago,brain size had
increased somewhat in early Homocompared with the ape-size brains
of australopithecines.This increase was accompanied by a rearrange-
ment of the convolutions of the frontal lobes,resulting in a more human-
like pattern in Homo.Specifically,the endocast of the left frontal
lobe of specimen KNM-ER 1,470 (Homo rudolfensis) revealed sulci
that are not seen in brains of apes or australopithecines,which delimit
Broca’s speech area in humans (Tobias 1981;Falk 1983).Shape also
changed due to apparent expansion in prefrontal cortex (Falk 1983).Fur-
thermore,analysis of contemporaneous stone tools suggests that knap-
pers had become right-handed by that time (Toth 1985).However,the213 Hominid Brain Evolution and the Origins of Music