From: Mark Crosby (crosby_m@rocketmail.com)
Date: Wed Aug 20 1997 - 13:32:03 MDT
The subject line is the title of a 1992 (?) book by Merlin Donald,
Department of Psychology, Queen's University, Kingston, Ontario,
Canada, _ Origins of the Modern Mind: Three Stages in the Evolution of
Culture and Cognition_. I found Donald’s fascinating precis at
http://www.cogsci.soton.ac.uk/bbs/Archive/bbs.donald.html
If this is old stuff, forgive me. Otherwise, here’s a summary, which
seems relevant to theories of "the augmented animal", memory models
and AI. All of the following is snipped from the essay at the above
URL.
Mark Crosby
Abstract: [SNIP] My central hypothesis is that there were three major
cognitive transformations by which the modern human mind emerged over
several million years, starting with a complex of skills presumably
resembling those of the chimpanzee. These transformations left, on the
one hand, three new, uniquely human systems of memory representation,
and on the other, three interwoven layers of human culture, each
supported by its corresponding set of representations. [SNIP]
The first transition introduced two fundamentally new cognitive
features: a supramodal, motor-modelling capacity called mimesis, which
created representations that had the critical property of voluntary
retrievability. The second transition added two more features: a
capacity for lexical invention, and a high-speed phonological
apparatus, the latter being a specialized mimetic subsystem. The third
transition introduced external memory storage and retrieval, and a new
working memory architecture. [SNIP]
Apes have episodic memory, that is the ability to store their
perceptions of specific episodes. However, they have very poor
episodic recall, because they cannot self-trigger their memories: that
is, they have great difficulty in gaining voluntarily access to the
contents of their own episodic memories independently of environmental
cues. Thus they are largely environmentally- driven, or conditioned,
in their behavior, and show very little independent thought that is
not directly related to specific episodes. I have called their style
of thought and culture "episodic." [SNIP] They can learn signs made
available by human trainers, but they do not invent them on their own;
nor do they seem to consciously "model" their patterns of movement, in
the sense of reflecting on them, experimenting with them, and pushing
them to the limits, the way humans do. This seems to indicate that
they are far less developed than humans in at least two areas of motor
control: the construction of conscious action-models, and the
independent voluntary retrieval of such models. [SNIP] Thus apes are
not good at improving their skills through systematic rehearsal. The
contrast with human children in this regard is striking. [SNIP]
First transition: mimetic skill and autocueing
The rationale for the first transition is based on several premises:
(a) the first truly human cognitive breakthrough was a revolution in
motor skill--mimetic skill--which enabled hominids to use the whole
body as a representational device; (b) this mimetic adaptation had two
critical features: it was a multimodal modelling system, and it had a
self-triggered rehearsal loop (that is, it could voluntarily access
and retrieve its own outputs); (c) the sociocultural implications of
mimetic skill are considerable, and could explain the documented
achievements of Homo erectus; (d) in modern humans, mimetic skill in
its broadest definition is dissociable from language-based skills, and
retains its own realm of cultural usefulness; and (e) the mimetic
motor adaptation set the stage for the later evolution of language.
[SNIP]
Early language theories of evolution are seeking a "quick fix"
solution, a rapid leap to some form of language without attending to
the more fundamental motoric changes that must have preceded it. (In
the process, of course, these theories also sustain the AI agenda that
attributes all higher cognition to some sort of symbolizing process:
see Dennett, 1992). [SNIP]
Second transition: lexical invention
The rationale for the second transition is briefly as follows: (a)
since no linguistic environment yet existed, a move towards language
would have depended primarily on developing a capacity for lexical
invention; (b) phonological evolution was accelerated by the emergence
of this general capacity for lexical invention, and included a whole
complex of special neuronal and anatomical modifications for speech;
(c) the language system evolved as an extension of lexical skill, and
gradually extended to the labelling of relationships between words,
and also to the imposition of more and more complex metalinguistic
skills that govern the uses of words; and (d) the natural collective
product of language was narrative thought, (essentially, storytelling)
which evolved for specific social purposes, and serves essentially
similar purposes in modern society. [SNIP]
Third transition: the externalization of memory
The case for a third cognitive transition is based on arguments,
partly structural, and partly chronological, that are similar in
principle to those used for the first two; but the physical factors
that supported the third transition are a little different, inasmuch
as the latter was driven primarily by technological, rather than
biological developments. The chronological evidence is based on the
rapid emergence of whole new classes of memory representations --
external memory records -- as well as a major change in the types of
symbolic artifacts produced by humans. The structural argument is
based partly on neuropsychological and neurophysiological evidence
bearing on localization and plasticity, and partly on an analysis of
cognitive architecture in the context of our new relationship with
external memory. [SNIP]
The structural case can be stated as follows: (a) external memory has
introduced radical new properties into the collective storage and
retrieval systems of humans; (b) the use of these external storage
systems is difficult, and requires a major re-deployment of cerebral
resources towards establishing literacy- related "modules" in the
brain; (c) the physiological basis for this reorganization probably
lies in neuronal epigenesis and plasticity; and (d) the role of
biological working memory has been changed by the heavy use of
external memory. [SNIP]
The external display projects directly to the visual regions, which
now become the locus of a new kind of internal working memory, one
which utilizes the power of the perceptual systems. In effect, because
the perceptual systems are displaying representations (as opposed to
nonsymbolic objects), the user's brain can move through "information
space" just as it has always moved through the natural environment,
with the difference that processing occurs on two levels, instead of
only one. The items displayed in the external memory field are treated
first as natural objects and events, and second as memory
representations that can externally program the user's brain, that is,
create specific states of knowledge that were intended by the creator
of the particular external device on display.
[SNIP to final paragraph]
The modern brain must accommodate not only these new working memory
arrangements, and all the coding demands imposed by symbolic literacy,
but also a number of metalinguistic skills that simply did not exist a
few thousands of years ago. The latter are socially-entrenched; for
instance an enterprise like modern science is very much a collective
endeavor, in which the individual mind is essentially a node in a
larger networked structure supported by external memory. Humans have
been part of a collective knowledge enterprise ever since mimetic
skill permitted us to break with the limitations of episodic
cognition, but external memory has amplified the number and variety of
representations available in human culture, and increased the degree
to which our minds share representations and rely on external devices
for the process of thought itself. Cognitive studies of the modern
workplace testify to the way that electronically distributed knowledge
representation, and computer-coordinated planning and problem-solving,
are affecting the relative roles of individual minds and external
memory devices in this collective enterprise.
_____________________________________________________________________
Sent by RocketMail. Get your free e-mail at http://www.rocketmail.com
This archive was generated by hypermail 2.1.5 : Fri Nov 01 2002 - 14:44:45 MST