psych4 |
An
Example of a "Learning Process" Journal (using the 2 colored
box format) |
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November
9, 2003 |
Book: The Number Sense by Stanislas Debaene
Source: Oxford University Press 1997
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I completed reading The Number Sense yesterday.
Here are the remaining notes. |
Yellow highlighted passages: Chap. 5 Small
Heads for Big Calculations
- "While children easily acquire number syntax, learning
to calculate can be an ordeal. ... Why is mental calculation
so difficult?" [p. 118]
- "An innate sense of approximate numerical quantities may
well be embedded in our genes; but when faced with exact
symbolic calculation, we lack proper resources." [p. 119]
- "By their fourth year, children have mastered the basics
of how to count. ... The origins of this precocious competence
remain poorly understood." [p. 120]
- "Reciting words in a fixed order is probably a natural
outcome of the human faculty for language. As to the principle
of one-to-one correspondence, it is actually widespread in
the animal kingdom. ... The counting algorithm stands at
the intersection of these two elementary abilities of the
human brain - word recitation and exhaustive search." [p.
120]
- "Though children rapidly grasp the how to of counting,
however, they seem to initially ignore the why. ... children
do not appreciate the meaning of counting until the end of
their fourth year." [p. 121]
- "Remember that right from birth, way before they start
to count, children have an internal accumulator that informs
them of the approximate number of things that surround them.
... Suppose the child is playing with two dolls ... the child
has learned that the word 'two' applies to this quantity
[subitizing plus vocabulary, just like learning when to use
the word dog], so that he can say 'two dolls' without having
to count. Now suppose that for no particular reason, he decides
to 'play the counting game' with the dolls, and recites the
words 'one two.' He will be surprised to discover that the
last number of the count, 'two', is the very word that can
apply to the entire set. After ten or twenty such occasions,
he may soundly infer that whenever one counts, the last word
arrived at has a special status. ... Counting, which was
only an entertaining word game, suddenly acquires a special
meaning: Counting is the best way of saying how many!" [p.
121]
- "With the help of counting, most children find ways of
adding and subtracting numbers without requiring any explicit
teaching." [p. 122]
- "Calculation abilities do not emerge in an immutable
order. Each child behaves like a cook's apprentice who tries
a random recipe, evaluates the quality of the result, and
decides whether or not to proceed in this direction." [p.
121]
- "During the preschool years ... Children suddenly shift
from an intuitive understanding of numerical quantities,
supported
by simple
counting strategies,
to a rote learning of arithmetic. ... this major turn coincides
with the first serious difficulties that children encounter
in mathematics." [p. 126]
- "What makes the multiplication table so much harder to
retain, even after years of training? The answer lies in
the particular structure of the addition and multiplication
tables."
[p. 127]
- "If our brain fails to retain arithmetic facts, that
is because the organization of human memory, unlike that
of a computer, is associative: It weaves multiple links among
disparate data, Associative links permit the reconstruction
of memories on the basis of fragmented information." [p.
127]
- "Associative memory is a strength as well as a weakness.
It is a strength when it enables us, starting from a vague
reminiscence, to unwind a whole ball of memories that once
seemed lost. ... It is a strength again when it permits us
to take advantage of analogies and allows us to apply knowledge
acquired under other circumstances to a novel situation.
Associative memory is a weakness, however, in domains such
as the multiplication table where the various pieces of knowledge
must be kept form interfering with each other at all costs.
... But when trying to retrieve the result of 7x6, we court
disaster by activating our knowledge of 7+6 or of 7x5. ...
our brain evolved for millions of years in an environment
where the advantages of associative memory largely compensated
for its drawbacks." [p. 128]
- "In order to calculate fast, the brain is forced to ignore
the meaning of the computations it performs." [p. 132]
- "Clearly, the human brain ... has not evolved for the purpose
of formal calculation." [p. 134]
- "We cannot hope to alter the architecture of our brain,
but we can perhaps adapt our teaching methods to the constraints
of our biology. Since arithmetic tables and calculation algorithms
are, in a way, counter natural, I believe that we should
seriously ponder the necessity of inculcating them in our
children."
[p. 134]
- "I am convince that by releasing children from the tedious
and mechanical constraints on calculation, the calculator
can help them to concentrate on meaning." [p. 135]
- "Electronic calculators, as well as mathematical software
for children, hold the promise of initiating them to the
beauty of mathematics: a role that teachers, all too occupied
in teaching the mechanics of calculation, often do not accomplish."
[p. 136]
- "Yet it should be acknowledged that today the vast
majority of adults never perform a multidigit calculation
without resorting to electronics. Whether we like it or not,
division and subtraction algorithms are endangered species
quickly disappearing from our everyday lives - except in
schools, where we still tolerate their quiet oppression." [p.
136]
- "In China, children are explicitly taught to reorder multiplications
by placing the smallest digit first. This elementary trick,
which avoids relearning 9x6 when one already knows 6x9, cuts
the amount of information to be learned by almost one half."
[p. 136]
- "Lacking any deep understanding of arithmetic principles,
they are at risk of becoming little calculating machines
that compute but do not think." [p. 136]
- "... number knowledge does not rest on a single specialized
brain area, but on vast distributed networks of neurons,
each performing its own simple, automated, and independent
computation." [p. 138]
- "... schooling plays a crucial role not so much because
it teaches children new arithmetic techniques, but also because
it helps them draw links between the mechanics of calculation
and its meaning. A good teacher is an alchemist who gives
a fundamentally modular human brain the semblance of an interactive
network." [p. 139]
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The example from China emphasizes that there
are gains to be made by being aware of other approaches to pedagogy,
as well as to the use of technology.
This is the best chapter in the whole book! |
Yellow highlighted passages: Chap. 6 Geniuses
and Prodigies
- "[while discussing math prodigies] - can psychology
or neurology propose at least an embryo of an explanation for
the extraordinary fertility of this unique mind?" [p. 146]
- "The role of memory in mathematics is easily underestimated.
... Their familiarity with numbers is so refined..." [p. 147]
- "The tight link between mathematical and spatial aptitudes
has often been empirically demonstrated." [p. 150]
- "Great mathematicians' intuitions about numbers and other
mathematical objects do not seem to rely so much on clever
symbol manipulations as on a direct perception of significant
relations." [p. 151]
- "In the mind of the calculating prodigy, each number does
not just light up as a point on a line, but rather as an arithmetical
web with links in every direction." [p. 151]
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Overall this chapter did not have much to
offer, at least on the first reading.
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Yellow highlighted passages: Chap. 7 Losing
Number Sense
- "Cerebral lesions of various origins can have a devastating
and sometimes surprisingly specific impact on arithmetic abilities."
[p. 175]
- "The extreme modularity of the human brain stands out as
the main lesson to be gathered from studies of cerebral pathology."
[p. 177]
- "For most researchers, these models are but provisional
metaphors." [p. 200]
- "Prefrontal areas comprise a multitude of networks." [p.
200]
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Yellow highlighted passages: Chap. 8 The
Computing Brain
- "... many recent experiments in brain imaging are conceived
in a 'neo-phrenological' framework. Their only objective seems
to be the labeling of cerebral areas." [p. 216]
- "We have every reason to think that the brain does not work
this way. Even seemingly simple functions call for the coordination
of a large number of cerebral areas. ... Ten or twenty cerebral
areas are activated when the subject reads words, ponders over
their meaning, imagines a scene, or performs a calculation.
... Only by combining the capacities of several million neurons,
spread out in distributed cortical and subcortical networks,
does the brain attain it s impressive computational power."
[p. 217]
- "If possible, we would want to obtain a new image of
brain activity every hundredth of a second. ... PET scanning
... its excellent spatial resolution is accompanied by a deplorable
temporal resolution. Each image depicts the average blood flow
over a period of at least forty seconds." [p. 221]
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The comment on PET scans certainly undermines
their value in cognitive research.
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Yellow highlighted passages: Chap. 9 What
is a Number?
- "A mathematician is a machine for turning coffee into theorems".
[p. 231]
- "The preceding chapters abound in counterexamples that suggest
that the human brain does not calculate like a 'logical machine'"
[p. 233]
- "The inadequacy of the brain-computer metaphor is almost
comical. In domains in which the computer excels - the faultless
execution of a long series of logical steps - our brain turns
out to be slow and fallible. Conversely, in domains in which
computer science meets its most serious challenges - shape
recognition and attribution of meaning - our brain shines by
its extraordinary speed." [p. 234]
- "In a recent book called Descartes' Error, the neuropsychologist
Antonio Damasio demonstrates how emotions and reason are tightly
linked." [p. 235]
- "If educational psychologists had paid enough attention to
the primacy of intuition over formal axioms in the human mind,
a breakdown without precedent in the history of mathematics
might have been avoided [modern math curriculum]." [p. 241]
- "The child's brain, far from being a sponge, is a structured
organ that acquires facts only insofar as they can be integrated
into its previous knowledge. It is well adapted to the representation
of continuous quantities and to their mental manipulation in
an analogical form." [p. 241]
- "Thus, bombarding the juvenile brain with abstract axioms
is probably useless. A more reasonable strategy for teaching
mathematics would appear to go through a progressive enrichment
of children's intuitions, leaning heavily on their precocious
understanding of quantitative manipulations and of counting.
... Then, little by little, one may introduce them to the power
of symbolic mathematical notation ... but at this stage, great
care should be taken never to divorce such symbolic knowledge
from the child's quantitative intuitions." [p. 241]
- "Numbers, like other mathematical objects, are mental
constructions whose roots are to be found in the adaptation
of the human mind to the regularities of the universe." [p.
252]
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Descartes Error is another of my favorite
books!
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Reminder: each "Learning" session has a new web page.
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