[Paleopsych] SW: Language and the Origin of Numerical Concepts
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Cognition: Language and the Origin of Numerical Concepts
http://scienceweek.com/2004/sa041210-5.htm
The following points are made by R. Gelman and C.R. Gallistel (Science
2004 306:441):
1) Intuitively, our thoughts are inseparable from the words in which
we express them. This intuition underlies the strong form of the
Whorfian hypothesis (after Benjamin Whorf (1897-1941), namely, that
language determines thought (aka "linguistic determinism"). Many
cognitive scientists find the strong hypothesis unintelligible and/or
indefensible (1), but weaker versions of it, in which language
influences how we think, have many contemporary proponents (2,3).
2) The strong version rules out the possibility of thought in animals
and humans who lack language, although there is an abundant
experimental literature demonstrating quantitative inference about
space, time, and number in preverbal humans (4), in individuals with
language impairments (5), and in rats, pigeons, and insects. Another
problem is the lack of specific suggestions as to how exposure to
language could generate the necessary representational apparatus. It
would be wonderful if computers could be made to understand the world
the way we do just by talking to them, but no one has been able to
program them to do this. This failure highlights what is missing from
the strong form of the hypothesis, namely, suggestions as to how words
could make concepts take form out of nothing.
3) The antithesis of the strong Whorfian hypothesis is that thought is
mediated by language-independent symbolic systems, often called the
language(s) of thought. Under this account, when humans learn a
language, they learn to express in it concepts already present in
their prelinguistic system(s). Their prelinguistic systems for
representing the world are language-like only in that they are
compositional: Larger, more complex meanings (concepts) are built up
by the combination of elementary meanings.
4) Recently reported experimental studies with innumerate Piraha and
Munduruku Indian subjects from the Brazilian Amazonia give evidence
regarding the role of language in the development of numerical
reasoning. Either the subjects in these reports have no true number
words or they have consistent unambiguous words for one and two and
more loosely used words for three and four. Moreover, they do not
overtly count, either with number words or by means of tallies. Yet,
when tested on a variety of numerical tasks -- naming the number of
items in a stimulus set, constructing sets of equivalent number,
judging which of two sets is more numerous, and mental addition and
subtraction -- these subjects gave results indicative of an imprecise
nonverbal representation of number, with a constant level of
imprecision, measured by the Weber fraction. The Weber fraction for
these subjects is roughly comparable to that of numerate subjects when
they do not rely on verbal counting. In one of the reports, the
stimulus sets had as many as 80 items, so the approximate
representation of number in these subjects extends to large numbers.
5) Among the most important results in these reports are those showing
simple arithmetic reasoning -- mental addition, subtraction, and
ordering. These findings strengthen the evidence that humans share
with nonverbal animals a language-independent representation of
number, with limited, scale-invariant precision, which supports simple
arithmetic computation and which plays an important role in elementary
human numerical reasoning, whether verbalized or not (5). The results
do not support the strong Whorfian view that a concept of number is
dependent on natural language for its development. Indeed, they are
evidence against it. The results are, however, consistent with the
hypothesis that learning to represent numbers by some communicable
notation (number words, tally marks, numerals) might facilitate the
routine recognition of exact numerical equality.
References (abridged):
1. L. Gleitman, A. Papafragou, in Handbook of Thinking and Reasoning,
K. J. Holyoak, R. Morrison, Eds. (Cambridge Univ. Press, New York, in
press)
2. D. Gentner, S. Golden-Meadow, Eds., Language and Mind: Advances in
the Study of Language and Thought (MIT Press, Cambridge, MA, 2003)
3. S. C. Levinson, in Language and Space, P. Bloom, M. Peterson, L.
Nadel, M. Garrett, Eds. (MIT Press, Cambridge, MA, 1996), Chap. 4
4. R. Gelman, S. A. Cordes, in Language, Brain, and Cognitive
Development: Essays in Honor of Jacques Mehler, E. Dupoux, Ed. (MIT
Press, Cambridge, MA, 2001), pp. 279-301
5. B. Butterworth, The Mathematical Brain (McMillan, London, 1999)
Science http://www.sciencemag.org
--------------------------------
Related Material:
COGNITIVE SCIENCE: NUMBERS AND COUNTING IN A CHIMPANZEE
Notes by ScienceWeek:
In this context, let us define "animals" as all living multi-cellular
creatures other than humans that are not plants. In recent decades it
has become apparent that the cognitive skills of many animals,
especially non-human primates, are greater than previously suspected.
Part of the problem in research on cognition in animals has been the
intrinsic difficulty in communicating with or testing animals, a
difficulty that makes the outcome of a cognitive experiment heavily
dependent on the ingenuity of the experimental approach.
Another problem is that when investigating the non-human primates, the
animals whose cognitive skills are closest to that of humans, one
cannot do experiments on large populations because such populations
either do not exist or are prohibitively expensive to maintain. The
result is that in the area of primate cognitive research reported
experiments are often "anecdotal", i.e., experiments involving only a
few or even a single animal subject.
But anecdotal evidence can often be of great significance and have
startling implications: a report, even in a single animal, of
important abstract abilities, numeric or conceptual, is worthy of
attention, if only because it may destroy old myths and point to new
directions in methodology. In 1985, T. Matsuzawa reported experiments
with a female chimpanzee that had learned to use Arabic numerals to
represent numbers of items. This animal (which is still alive and
whose name is "Ai") can count from 0 to 9 items, which she
demonstrates by touching the appropriate number on a touch-sensitive
monitor. Ai can also order the numbers from 0 to 9 in sequence.
The following points are made by N. Kawai and T. Matsuzawa (Nature
2000 403:39):
1) The author report an investigation of Ai's memory span by testing
her skill in numerical tasks. The authors point out that humans can
easily memorize strings of codes such as phone numbers and postal
codes if they consist of up to 7 items, but above this number of
items, humans find memorization more difficult. This "magic number 7"
effect, as it is known in human information processing, represents an
apparent limit for the number of items that can be handled
simultaneously by the human brain.
2) The authors report that the chimpanzee Ai can remember the correct
sequence of any 5 numbers selected from the range 0 to 9.
3) The authors relate that in one testing session, after choosing the
first correct number in a sequence (all other numbers still masked),
"a fight broke out among a group of chimpanzees outside the room,
accompanied by loud screaming. Ai abandoned her task and paid
attention to the fight for about 20 seconds, after which she returned
to the screen and completed the trial without error."
4) The authors conclude: "Ai's performance shows that chimpanzees can
remember the sequence of at least 5 numbers, the same as (or even more
than) preschool children. Our study and others demonstrate the
rudimentary form of numerical competence in non-human primates."
Nature http://www.nature.com/nature
--------------------------------
Related Material:
COGNITIVE SCIENCE: ON THE MENTAL REPRESENTATION OF NUMBER
The following points are made by A. Plodowski et al (Current Biology
2003 13:2045):
1) How are numerical operations implemented within the human brain? It
has been suggested that there are at least three different codes for
representing number: a verbal code that is used to manipulate number
words and perform mental numerical operations (e.g., multiplication);
a visual code that is used to decode frequently used visual number
forms (e.g., Arabic digits); and an abstract analog code that may be
used to represent numerical quantities [1]. Furthermore, each of these
codes is associated with a different neural substrate [1-3].
2) Several features of numbers are of interest to cognitive
neuroscientists. First, investigations of animals and infants indicate
that the ability to process numerical magnitude can be independent of
language. Second, identical numerical quantities can be represented in
several different notations. Third, different numerical operations can
be performed on the same operands. Dehaene [1] has proposed a triple
code model that distinguishes between an auditory verbal code, a
visual code for Arabic digits, and an analog magnitude code that
represents numerical quantities as variable distributions of brain
activation. Dehaene and colleagues [1-3] propose that there are
specific relationships between individual numerical operations and
different numerical codes. The analog magnitude code is used for
magnitude comparison and approximate calculation, the visual Arabic
number form for parity judgments and multidigit operations, and the
auditory verbal code for arithmetical facts learned by rote (e.g.,
addition and multiplication tables).
3) Previous studies have used behavioral and neuroimaging techniques
(both ERP and fMRI) to explore the effects of notation (i.e., Arabic
versus verbal code) on magnitude estimation [2,3]. The authors extend
these studies using dense-sensor event-related EEG recording
techniques to investigate the temporal pattern of notation-specific
effects observed in a parity judgement (odd versus even) task in which
single numbers were presented in one of four different numerical
notations. Contrasts between different notations demonstrated clear
modulations in the visual evoked potentials (VEP) recorded. The
authors observed increased amplitudes for the P1 and N1 components of
the VEP that were specific to Arabic numerals and to dot
configurations but differed for random and recognizable (die-face) dot
configurations. The authors suggest these results demonstrate clear,
notation-specific differences in the time course of numerical
information processing and provide electrophysiological support for
the triple-code model of numerical representation.[4,5]
References (abridged):
1. Dehaene, S. (1992). Varieties of numerical abilities. Cognition 44,
1-42
2. Dehaene, S. (1996). J. Cogn. Neurosci. 8, 47-68
3 Pinel, P., Dehaene, S., Riviere, D., and LeBihan, D. (2001).
Neuroimage 14, 1013-1026
4. Guthrie, D. and Buchwald, J.S. (1991). Significance testing of
difference potentials. Psychophysiology 28, 240-244
5. Nunez, P.L., Silberstein, R.B., Cadusch, P.J., Wijesinghe, R.S.,
Westdorp, A.F., and Srinivasan, R. (1994). A theoretical and
experimental study of high resolution EEG based on surface Laplacians
and cortical imaging. Electroencephalogr. Clin. Neurophysiol. 90,
40-57
Current Biology http://www.current-biology.com
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