Re: Archaic H. sapiens???

Georgie Stanford (
27 Jan 1997 23:18:22 GMT

Michael McBroom ( wrote:
: Ralph L Holloway wrote:
: >
: > On Mon, 6 Jan 1997, Michael McBroom wrote:
: > > Being a student of linguistics, and specializing in the origins of
: > > language, (just so you know where my bias lies), I am a subscriber to
: > > the view that the genus Homo split off from Australopithecus once a
: > > system of vocal communication became a clear adaptive advantage. Recent
: > > works have pointed to the evidence of a Broca's area in H. habilis,
: > > based on depressions left in certain specimens' skulls. Last year,
: >
: > Being one of those involved in studying the brain endocasts of Homo
: > habilis since the early '70's, I remember pointing out Broca's area to
: > Richard Leakey on the KNM-ER 1470 skull. The rest of the Homo habilis
: > endocasts that I've worked, such as OH 7, OH 13, OH 24, don't have those
: > regions intact, so i don't know what recent works you are referring to.
: > Could you elaborate?
: Only Leakey and Lewin (1993) and Walker and Shipman (1996) refer
: specifically to KNM-ER 1470. Two other sources I have, Bickerton (1990)
: and Pinker (1994), refer simply to references citing evidence of Broca's
: area in Homo habilis. So, most likely they are referring to 1470 as
: well.
If I might add my $0.02 worth of opinion to this otherwise noble
conversation it would be that archaeologists seem to be paying
too much attention to what may be a very minor area of the brain.
While Broca's area (aka Brodmann's area 44 ) does have a minor role in
speech production it is more likely to merely facilitate mechanics than
produce any magic all-or-none phenomenom such as is commonly attributed
to it.

I fear that in common usage we've mixed up poor Boca's area
with the aphasia also named after him. The aphasia actually involves
not just area 44 but supporting ones as well. Sadly, he didn't
neccessarily cut his brains, relying at times on theory and surface
inspection so it comes to no surprise that latter day CT scans of
his specimens show he'd missed some deeper areas.

I've included a few references, which you will find assert that
the aphasia occurring in pure area 44 lesions is either "...modest and
transient motor speech disorder (Mohr et al) or to no disorder at
all (Goldstein)." (1)

(I don't want to sound like I know what I'm talking about. I'm not
a neurologist...indeed after surviving classes under that a**hole, Mohr,
I went into psychiatry instead, where at least we admit we don't always
know what we're about.)



(1) Adams RD, Victor M.: Principles of Neurology, fourth edition.
New York, McGraw -Hill, 1989, pp 377-395

(2) Adams RD, Victor M. Ropper AH: Principles of Neurology, sixth
edition New York, McGraw -Hill, 1997, pp 472-493

(3) Goldstein K: Language and Language Disturbances. New York.
Grune & Stratton, 1948, pp 190-216

(4) Mohr JP: Broca's area and Broca's aphasia, in Whitaker H: Studies
in Neurolinguistics, vol 1. New York, Academic, 1976, pp201-235

(5) Mohr JP: (unpublished lectures in undergraduate neurology clinical
clerkship elective, USAMC, 1979)

: > > however, Alan Walker & Pat Shipman, in their book _The Wisdom of the
: > > Bones_, discussed more recent studies of the brain while one is speaking
: > > or listening. The studies indicate that the areas of the brain which
: > > are active during speech and listening are diffused throughout the
: > > brain, so this takes away much of the previous argument for evidence of
: > > language in H. habilis. Broca's area is probably more of a junction or
: > > bottleneck than an origination area.
: >
: > It's quite true that other areas of the brain do light up during speech
: > and other language acts, including the cerebellum, but Broca's region
: > still remains heavily involved in the motor processing of language, so it
: > really need not "take away" the previous arguments regarding the
: > possibility of speech in Homo habilis.
: Does processing take place in Broca's area, though, or is it merely
: routed through it? I ask this because aphasias can be highly specific,
: which leads one to wonder if the damage to Broca's area may in fact be
: working to inhibit the flow that may have originated in another area.

Pardon, one more interruption. Think "deep brain structures". The outer
cortex may well just be dedicated RAM or at best site specific stack memory.