Prof. Ivo Schneider (Munchen)
"The philosophical, juridical and mathematical preliminaries of
probability theory"
cimmel eloadas-sorozatot tart
oktober folyaman hetfonkent ( 4.,11.,18.,25.) d.u 4 orakor,
a BME Kozp. epulet (Muegyetem rkp. 3) I.emelet 59-ben,
angol nyelven.
Erdeklodoket szivesen latunk!
BME GTK Filozofia es Tudomanytortenet Tanmszek
--
Laszlo E. Szabo
Department of Theoretical Physics
Department of History and Philosophy of Science
Eotvos University, Budapest
H-1518 Budapest, Pf. 32.
Phone: (36-1)2090-555/6671
Fax: (36-1)372-2509
Home: (36-1)200-7318
http://hps.elte.hu/~leszabo
ELTE TTK Tudomanytortenet es Tudomanyfilozofia Tanszek
Budapest, Pazmany P. setany 1/A
TUDOMANYFILOZOFIA SZEMINARIUM
(http://hps.elte.hu)
________________________________________________
1999. oktober 4. (hetfo)
12:30
6. em. 654. (661 a regi szamozas szerint)
T o m a s z P l a c e k
Department of Philosophy, Jagiellonian University, Cracow
OUTCOMES IN BRANCHING SPACE-TIME (OBST)
-AN ANALYSIS OF BELL'S THEOREM-
The framework of BRANCHING SPACE-TIME (BST; cf. Belnap 1992, SYNTHESE
92, pp. 385--434) has recently been extended to allow for the
introduction of outcomes of events and the analysis of GHZ theorems.
(Kowalski & Placek, forthcoming in BRIT. J. PHIL. SCI. and INT. J.
THEOR. PHYS.)
In BST, space-time and modality are incorporated in the very structure
of the models, which consist of a pair $\langle W, \leq \rangle$, where
$W$ is a non-empty set weakly ordered by $\leq$, which is interpreted as
`causally accessible from.' Maximal upward directed subsets of $W$ are
called `histories,' and proper subsets of histories are called `events.'
Two events are called `space-like separated' if neither causally
precedes the other. `Atomic outcomes' of an event $E$ are those parts of
the event's causal future that split in $E$.
The main result of Kowalski & Placek is that the family of outcomes of
an event forms a Boolean algebra. The paper also proves that in GHZ
setups, there is always a common cause (CC) in the sense of Reichenbach
if directions are held fixed, but that there is no single COMMOM common
cause (cf. Hofer-Szabo et al., forthcoming in BRIT. J. PHIL. SCI.)
accounting for the outcomes of incompatible settings.
For an analysis of Bell's theorem, I assign probabilities to outcomes by
imposing a classical probability measure on the Boolean algebra of the
outcomes of each given event. In the derivation of Bell's theorem, I use
probability measures of the form $p_{L\alpha \cup R\beta}(Lx \cap Ry)$,
$x,y \in \{+,-\}$, where the subscript indicates that the result is an
outcome of the event of measuring the spin projections along directions
$\alpha$ on the left and $\beta$ on the right. Probabilities for single
results on the left or on the right are calculated from these measures,
allowing us to express correlations as $p_{L\alpha \cup R\beta}(Lx \cap
Ry) \neq p_{L\alpha \cup R\beta}(Lx) \times p_{L\alpha \cup
R\beta}(Ry)$.
Since correlations between space-like separated results appear
disturbing, it is natural to look for an explanation in terms of a CC
located in the results' common past. The CC's outcomes divide histories
in such a way that actual runs of a correlation experiment are seen as
belonging to two or more varieties differentiated by hidden factors. You
may think of these hidden factors as restoring the deterministic order.
You may also be more modest and require only that the hidden factors
restore the causal order, i.e., that in each sub-population, the
correlations disappear.
Formally, for space-like separated events $E$ and $F$ with correlated
outcomes $e$ and $f$, respectively, a CC is an event C preceding both
$e$ and $f$, such that for every atomic outcome $\omega_{i}$ of $C$,
$$ p_{E\cup F\cup C}(e \cap f|\omega_{i}) = p_{E\cup F\cup C}(e
|\omega_{i}) \times p_{E \cup F\cup C}(f|\omega_{i})$$,
where $p_{E \cup F \cup C}$ is defined on the enlarged probability
space. Now, for any correlated pair $e,f$, we CAN construct
mathematically an enlarged probability space containing such a CC.
Moreover, for any finite number of correlations we CAN construct a
single large probability space containing a set of distinct CCs, each CC
taking care of one correlation. However, in the Bell/Clauser-Horne
argument, one wants something more: one postulates a single common CC
accounting for all the correlated outcomes of $L\alpha\cup R\beta$,
$L\alpha\cup R\beta--\prime$, $L\alpha--\prime\cup R\beta$, and
$L\alpha--\prime\cup R\beta--\prime$. Given the standard assumptions of
locality and `no conspiracy,' which in our framework take the form
\begin{equation*}
\begin{split}
& \forall \alpha, \beta, \varphi, x p_{L\alpha \cup R\beta\cup C}(Lx)
= p_{L\alpha \cup R\varphi\cup C}(Lx)\ & \forall \alpha, \beta, \gamma,
y p_{L\alpha \cup R\beta\cup C}(Ry) = p_{L\gamma \cup R\beta\cup
C}(Ry)
\end{split}
\tag{LOCALITY}
\end{equation*}
\begin{equation*}
\forall \alpha, \beta, \gamma, \varphi, i p_{L\alpha \cup R\beta\cup
C}(\omega_i) = p_{L\gamma \cup R\varphi\cup C}(\omega_i),
\tag{NO CONSPIRACY}
\end{equation*}
we derive the Bell/CH inequalities, which are empirically violated.
Thus, there cannot be a common common cause accounting for the Bell/CH
correlations.
--
Laszlo E. Szabo
Department of Theoretical Physics
Department of History and Philosophy of Science
Eotvos University, Budapest
H-1518 Budapest, Pf. 32.
Phone: (36-1)2090-555/6671
Fax: (36-1)372-2509
Home: (36-1)200-7318
http://hps.elte.hu/~leszabo
Csaba Pleh
Cognitive Science Group
Department of Psychology
Attila Jozsef University, Szeged
Petofi sgt 30-34, 6722 Hungary
Phone: (36)(62) 454000, extension 3273
Home: Budakeszi Zichy P. u. 4 2092 Hungary, (36)(23) 453932 or 933
Editor, Hungarian Review of Psychology
---------- Forwarded message ----------
Date: Tue, 28 Sep 1999 10:51:47 -0400
From: Cynthia Bradford <cindy(a)cns.bu.edu>
To: cindy(a)cns.bu.edu
Subject: ICCNS 2000
Resent-Date: Tue, 28 Sep 99 18:55:19 +100
Resent-From: PLEH(a)izabell.elte.hu
Resent-To: pleh(a)sol.cc.u-szeged.hu
Enclosed below is a conference announcement. If
you would prefer not to receive further emails
of this type from us, please email me back and
your name will be removed from our mailing list.
Please accept our apologies in advance if you had
asked to be removed from this mailing list at an
earlier time. There was some miscommunication with
our previous computer systems manager, but please
be assured that you will be removed this time, should
you make such a request.
Sincerely,
Cynthia Bradford
Department Administrator
email: cindy(a)cns.bu.edu
***** CALL FOR PAPERS *****
FOURTH INTERNATIONAL CONFERENCE ON COGNITIVE AND NEURAL SYSTEMS
Tutorials: May 24, 2000
Meeting: May 25-27, 2000
Boston University
677 Beacon Street
Boston, Massachusetts 02215
http://cns-web.bu.edu/meetings/
Sponsored by Boston University's
Center for Adaptive Systems
and
Department of Cognitive and Neural Systems
This interdisciplinary conference has drawn about 300 people from around
the world each time that it has been offered. Last year's conference was
attended by scientists from 30 countries. The conference is structured to
facilitate intense communication between its participants, both in the
formal sessions and during its other activities. As during previous years,
the millennium conference will focus on solutions to the fundamental
questions:
How Does the Brain Control Behavior?
How Can Technology Emulate Biological Intelligence?
The conference will include invited tutorials and lectures, and
contributed lectures and posters by experts on the biology and
technology of how the brain and other intelligent systems adapt to a
changing world. The conference is aimed at researchers and students of
computational neuroscience, connectionist cognitive science,
artificial neural networks, neuromorphic engineering, and artificial
intelligence.
A single oral or poster session enables all presented work to be
highly visible.
Abstract submissions encourage submissions of the latest results.
Costs are kept at a minimum without compromising the quality of
meeting handouts and social events.
CALL FOR ABSTRACTS
Session Topics:
* vision * spatial mapping and navigation
* object recognition * neural circuit models
* image understanding * neural system models
* audition * mathematics of neural systems
* speech and language * robotics
* unsupervised learning * hybrid systems (fuzzy, evolutionary, digital)
* supervised learning * neuromorphic VLSI
* reinforcement and emotion * industrial applications
* sensory-motor control * cognition, planning, and attention
* other
Contributed abstracts must be received, in English, by January 28,
2000. Notification of acceptance will be provided by email by February
29, 2000. A meeting registration fee of $50 for regular attendees and
$35 for students must accompany each Abstract. See Registration
Information for details. The fee will be returned if the Abstract is
not accepted for presentation and publication in the meeting
proceedings. Registration fees of accepted abstracts will be returned
on request only until April 14, 2000.
Each Abstract should fit on one 8.5" x 11" white page with 1" margins
on all sides, single-column format, single-spaced, Times Roman or
similar font of 10 points or larger, printed on one side of the page
only. Fax submissions will not be accepted. Abstract title, author
name(s), affiliation(s), mailing, and email address(es) should begin
each Abstract. An accompanying cover letter should include: Full title
of Abstract; corresponding author and presenting author name, address,
telephone, fax, and email address; and a first and second choice from
among the topics above, including whether it is biological (B) or
technological (T) work. Example: first choice: vision (T); second
choice: neural system models (B). (Talks will be 15 minutes
long. Posters will be up for a full day. Overhead, slide, and VCR
facilities will be available for talks.) Abstracts which do not meet
these requirements or which are submitted with insufficient funds will
be returned. Accepted Abstracts will be printed in the conference
proceedings volume. No longer paper will be required. The original and
3 copies of each Abstract should be sent to: Cynthia Bradford, Boston
University, Department of Cognitive and Neural Systems, 677 Beacon
Street, Boston, MA 02215.
REGISTRATION INFORMATION: Early registration is recommended. To
register, please fill out the registration form below. Student
registrations must be accompanied by a letter of verification from a
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an Abstract or if paying by check, mail to the address above. If
paying by credit card, mail as above, or fax to (617) 353-7755, or
email to cindy(a)cns.bu.edu. The registration fee will help to pay for a
reception, 6 coffee breaks, and the meeting proceedings.
STUDENT FELLOWSHIPS: Fellowships for PhD candidates and postdoctoral
fellows may be available to cover meeting travel and living costs.
This will be confirmed one way or the other, and broadly advertised if
confirmed, before the deadline to apply for fellowship support, which
will be January 28, 2000. Applicants will be notified by email by
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including name; mailing address; email address; current student status;
faculty or PhD research advisor's name, address, and email address;
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articles. A letter from the listed faculty or PhD advisor on official
institutional stationery should accompany the application and summarize
how the candidate may benefit from the meeting. Students who also submit
an Abstract need to include the registration fee with their Abstract.
Fellowship checks will be distributed after the meeting.
REGISTRATION FORM
Fourth International Conference on Cognitive and Neural Systems
Department of Cognitive and Neural Systems
Boston University
677 Beacon Street
Boston, Massachusetts 02215
Tutorials: May 24, 2000
Meeting: May 25-27, 2000
FAX: (617) 353-7755
http://cns-web.bu.edu/meetings/
(Please Type or Print)
Mr/Ms/Dr/Prof: _____________________________________________________
Name: ______________________________________________________________
Affiliation: _______________________________________________________
Address: ___________________________________________________________
City, State, Postal Code: __________________________________________
Phone and Fax: _____________________________________________________
Email: _____________________________________________________________
The conference registration fee includes the meeting program,
reception, two coffee breaks each day, and meeting proceedings.
The tutorial registration fee includes tutorial notes and two
coffee breaks.
CHECK ONE:
( ) $75 Conference plus Tutorial (Regular)
( ) $50 Conference plus Tutorial (Student)
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METHOD OF PAYMENT (please fax or mail):
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Richardson: HYPERSTRUCTURE IN BRAIN AND COGNITION
http://www.cogsci.soton.ac.uk/cgi/psyc/newpsy?10.031
The target whose abstract appears below has just appeared in
PSYCOLOQUY, a refereed journal of Open Peer Commentary sponsored by
the American Psychological Association. Qualified professional
biobehavioral, neural or cognitive scientists are hereby invited to
submit Open Peer Commentary on it. Please email or see websites for
Instructions if you are not familiar with format or acceptance
criteria for PSYCOLOQUY commentaries (all submissions are
refereed).
To link to the full text of this article:
http://www.cogsci.soton.ac.uk/cgi/psyc/newpsy?10.031
To submit articles and commentaries or to seek information:
EMAIL: psyc(a)pucc.princeton.edu
URL: http://www.princeton.edu/~harnad/psyc.htmlhttp://www.cogsci.soton.ac.uk/psyc
-----------------------------------------------------------------------
psycoloquy.99.10.031.hyperstructure.richardson Thu Sep 23 1999
ISSN 1055-0143 (71 pars, 60 refs, 6 figs, 1 table, 1389 lines)
PSYCOLOQUY is sponsored by the American Psychological Association (APA)
Copyright 1999 Ken Richardson
HYPERSTRUCTURE IN BRAIN AND COGNITION
Target Article on Hyperstructure
Ken Richardson
Centre for Human Development & Learning
The Open University
Walton Hall
Milton Keynes MK7 6AA
United Kingdom
k.richardson(a)open.ac.uk
ABSTRACT: This target article tries to identify the informational
content of experience underlying object percepts and concepts in
complex, changeable environments, in a way which can be related to
higher cerebral functions. In complex environments, repetitive
experience of feature- and object-images in static, canonical form
is rare, and this remains a problem in current theories of
conceptual representation. The only reliable information available
in natural experience consists of nested covariations or
'hyperstructures'. These need to be registered in a
representational system. Such representational hyperstructures can
have novel emergent structures and evolution into 'higher'
forms of representation, such as object concepts and event- and
social-schemas. Together, these can provide high levels of
predictability. A sketch of a model of hyperstructural functions in
object perception and conception is presented. Some comparisons
with related views in the literature of the recent decades are
made, and some empirical evidence is briefly reviewed.
KEYWORDS: complexity, covariation, features, hypernetwork,
hyperstructure, object concepts, receptive field, representation
http://www.cogsci.soton.ac.uk/cgi/psyc/newpsy?10.031
ELTE TTK Tudomanytortenet es Tudomanyfilozofia Tanszek
Budapest, Pazmany P. setany 1/A
TUDOMANYFILOZOFIA SZEMINARIUM
(http://hps.elte.hu/~leszabo/szeminar/folap.htm)
________________________________________________
1999. Szeptember 27. (hetfo !)
12:30
6. em. 661.
B a r r y L o e w e r
Rutgers University
Collegium Budapest
PROBABILITY AND DETERMINISM
Although probability is essential to the formulation (and evaluation) of
scientific theories and although a great deal is known about how to
employ probabilistic concepts, there is still philosophical controversy
concerning the nature of probability. Some hold that only probability
concerns only degrees of belief (either subjective or constrained by
"objective" rules) while others hold that it concerns mind-independent
features of reality. The latter view divides among those who hold that
it concerns only frequencies (actual or hypothetical) and those who hold
that it concerns a "causal propensity." The nature of probability is
especially puzzling when the underlying dynamics is completely
deterministic as in classical mechanics and Bohm's version of quantum
mechanics. Some claim that when the dynamics is deterministic then all
objective probabilities are 1 or 0. But this seems at odd with the
scientific practice. In my talk I will review some of the main ideas
concerning the nature of probability and also an idea suggested by David
Lewis. According to Lewis probability concerns an objective feature of
reality that supervenes on the totality of propositions not concerning
chance. Whether or not Lewis' account is correct for dynamical chances I
argue that it provides a good account of chance statements when the
dynamics are deterministic.
--
Laszlo E. Szabo
Department of Theoretical Physics
Department of History and Philosophy of Science
Eotvos University, Budapest
H-1518 Budapest, Pf. 32.
Phone: (36-1)2090-555/6671
Fax: (36-1)372-2509
Home: (36-1)200-7318
http://hps.elte.hu/~leszabo
M e g h i v o
Az alkotok es az XTV meghivja ont az
EMBER VAGY ORDOG - KI VOLT LAKATOS IMRE?
c. film vetitesere a Taban moziba (1016 Bp. Krisztina krt. 87-89.)
A vetites ideje: 1999. szeptember 22. (szerda) 18 ora
Rendezte: MEREI ANNA
--
Laszlo E. Szabo
Department of Theoretical Physics
Department of History and Philosophy of Science
Eotvos University, Budapest
H-1518 Budapest, Pf. 32.
Phone: (36-1)2090-555/6671
Fax: (36-1)372-2509
Home: (36-1)200-7318
http://hps.elte.hu/~leszabo
PSYCOLOQUY CALL FOR BOOK REVIEWERS
Below is the Precis of "The Neuropsychological Theories of Lashley
and Hebb" by Jack Orbach (427 lines). This book has been selected
for multiple review in PSYCOLOQUY. If you wish to submit a formal
book review please write to psyc(a)pucc.princeton.edu indicating what
expertise you would bring to bear on reviewing the book if you were
selected to review it.
(If you have never reviewed for PSYCOLOQUY or Behavioral & Brain
Sciences before, it would be helpful if you could also append a
copy of your CV to your inquiry.) If you are selected as one of the
reviewers and do not have a copy of the book, you will be sent a
copy of the book directly by the publisher (please let us know if
you have a copy already). Reviews may also be submitted without
invitation, but all reviews will be refereed. The author will reply
to all accepted reviews.
Full Psycoloquy book review instructions at:
http://www.princeton.edu/~harnad/psyc.htmlhttp://www.cogsci.soton.ac.uk/psycoloquy/
Relevant excerpts:
Psycoloquy reviews are of the book not the Precis. Length should be
about 200 lines [c. 1800 words], with a short abstract (about 50
words), an indexable title, and reviewer's full name and
institutional address, email and Home Page URL. All references that
are electronically accessible should also have URLs.
AUTHOR'S RATIONALE FOR SOLICITING COMMENTARY
My rationale for seeking open peer commentary is primarily that the
book says some things about both Lashley and Hebb that some peers
might find controversial and startling if not downright outrageous.
To get these views out in the open may be of pedagogical value not
only to to me but to the neuropsychological community at large.
Obviously, I don't believe that my arguments are wrong or weak. But
the feedback I get might conceivably persuade me to rethink the
matter.
psycoloquy.99.10.029.lashley-hebb.1.orbach Sat Sep 18 1999
ISSN 1055-0143 (16 paragraphs, 16 references, 427 lines)
PSYCOLOQUY is sponsored by the American Psychological Association (APA)
Copyright 1999 Jack Orbach
Precis of:
THE NEUROPSYCHOLOGICAL THEORIES OF LASHLEY AND HEBB
Precis of Orbach on Lashley-Hebb
[University Press of America, 1998 xiv, 395 pp. ISBN: 0-761-81165-6]
Jack Orbach
Department of Psychology
Queens College
Flushing, NY
U.S.A.
jorbach(a)worldnet.att.net
ABSTRACT: Beginning in the 1920s, K. S. Lashley startled
psychologists with his theories of the memory trace within the
cerebral cortex. Using terms such as terms mass action,
equipotentiality, and sensory/motor equivalence, Lashley presented
evidence that the engram is widely distributed in the brain, and
that unactivated synapses, like activated ones, seem to show
evidence of learning. His research and nativistic theories made him
world famous by 1929, when he was just 39. He spent his
professional career searching for a mechanism for the reduplication
of the engram. While his contemporaries tried to specify the locus
of the engram in the brain, Lashley found it everywhere. He liked
to quip that the problem is not to find where the trace is located,
but where it is not. Lashley's student, D. O. Hebb, published his
empiricistic theories in 1949, in "The Organization of Behavior,"
and the monograph created a sensation. Hebb used Lorente de No's
reverberatory circuit to provide a mechanism to maintain activity
in the cerebral cortex after the stimulus terminated, the so-called
central autonomous process. This led him to the cell assembly, a
complex reverberatory circuit that could be assembled by
experience. Changes in resistance at the synapse with learning came
to be called the Hebb synapse. That monograph was highly praised
for the breadth of its treatment. The present book documents how
Lashley anticipated Hebb's introduction of the reverberatory
circuit by some 12 years. Lashley's Vanuxem Lectures of 1952 are
printed for the first time, together with nine of his previously
published theoretical papers. Lashley's and Hebb's theories are
reviewed and reevaluated fifty years after publication of Hebb's
monograph, and a systematic effort is made to compare and contrast
the views of teacher and student.
KEYWORDS: cell assembly, central autonomous process, engram,
equipotentiality, Hebb, Hebbian learning, Lashley, localization,
memory trace, nativism, reverberatory circuit, Vanuxem Lectures
1. Part 1 of the book opens with a summary of Lashley's last public
lecture given at the University of Rochester in 1957, one year before
his death and eight years after the publication of Hebb's monograph. In
this lecture, Lashley was still consumed with the notion of irradiating
waves of excitation in the cerebral cortex, a notion he developed in
detail in 1942. In citing theories of stimulus equivalence, Lashley
wrote 'That of Hebb is most in accord with conditioned reflex theory.
He assumes that multiple paths are developed by learning. Such learning
is ruled out by a mass of evidence for innate discriminations and
equivalencies.' In this unpublished address, Lashley cited Hebb's
empiricistic theory for the first and only time. He never cited the
monograph itself in the literature.
2. An early chapter entitled 'Setting the Stage' offers another look at
Lashley's early critique of the native Watsonian connectionism of his
day. Lashley's early efforts to revise and revitalize
neuropsychological theory are reviewed. The problem, Lashley suggested
in the 1920s, was the omission of the brain from the Watsonian S-R
formula. And when a model of cortical function was finally introduced,
using the analogy of the telephone switchboard, it was based on the
idea of linear reflex activity in the spinal cord, as suggested by
Dewey, leaving no room for psychological categories that require
sustained activity in the brain such as thought, memory, emotion,
motivation, selective attention and the like. And then, along came
Pavlov who undercut all contemporary speculations of psychologists with
his physiological theories of conditioned reflexes and brain function.
It was at this point that Lashley burst upon the scene.
3. Hebb must have experienced an epiphany when he was introduced to the
reverberatory circuit of Lorente de N. He realized that this anatomical
curiosity provided him with a mechanism for the autonomous central
process that he developed so masterfully in the 1949 monograph. Hebb's
revelation involving the reverberatory circuit was especially important
for it gave neurological meaning to the earlier proposals of central
motive state of Morgan and central excitatory mechanism of Beach as
well as the putative reduplicated memory trace of Lashley. However,
Lashley had already appropriated the reverberatory circuit for
neuropsychological theory in 1937, some 12 years before Hebb's
monograph was published and some three years before its presentation by
Hilgard and Marquis in their Conditioning and Learning of 1940. This is
documented with excerpts from Lashley's papers published in 1937, 1938,
1941, 1942 and 1949. The latter two papers are republished in their
entirety in this volume.
4. The next chapter deals with the learning theory that synaptic
resistance is reduced by the passage of the nerve impulse. Lashley's
1924 assault on this theory is reviewed in detail. (This 1924 paper is
also reprinted in this volume.) In Lashley's own words, 'Among the many
unsubstantiated beliefs concerning the physiology of the learning
process, none is more widely prevalent than the doctrine that the
passage of the nerve impulse through the synapse somehow reduces
synaptic resistance and leads to the fixation of a new habit . . . but
no direct evidence for synaptic resistance has ever been obtained. The
hypothesis is not based upon neurological data but is merely a
restatement of the observed fact that increased efficiency follows
repeated performance . . . Familiar learning curves are obviously an
expression of these successive integrations and we have no knowledge of
the conditions prevailing in formation of a new simple neural
integration. (On the other hand,) the instantaneous character of
simpler associations in man . . . suggests that . . . a single
performance serves to fix the habit. Even if this were the case for
every simple reintegration within the nervous system, we should still
get the appearance of gradual improvement through practice because of
the formation of many simple associations . . . The fact of gradual
improvement in complex functions cannot therefore be taken as evidence
for a gradual wearing down of synaptic resistance by repeated passage
of the nerve impulse' (Lashley, 1924). The reemergence of this theory
in Hebb's monograph as a neuropsychological postulate is documented and
evaluated. In the fourth edition of Hebb's Textbook (1994), Donderi
refers to the postulate as Hebb's rule. Today, it is frequently
referred to as the Hebb synapse.
5. Next, 'Lashley's Memory Mechanisms', considers:
i. Lashley's view that the memory trace is reduplicated in the
cerebral cortex and the implications of that view on the
interpretation of cerebral localization. In 1952, Lashley wrote 'I
have never been able by any operation on the brain to destroy a
specific memory' even when the memory is elicited by electrical
stimulation of the part of the cerebral cortex that is subsequently
removed.
ii. Lashley's early introduction of the reverberatory circuit in
neuropsychological theory is documented. It is important to note
that Lashley never abandoned the principle of synaptic transmission
in favor of a cortical field theory, as had been alleged by Hebb
and others. This claim is fully documented.
iii. Lashley assumed throughout his career that memory is a unitary
function. He was of course aware of the distinction between long
and short term memory but he never referred to the modern
distinction between storage and retrieval. Nor did he ever consider
associative and working memory as distinct forms of memory when he
searched for the engram in the cerebral cortex.
iv. Lashley's position on the continuity-discontinuity debate is
reviewed as well as his championing the concept of instinct at a
time when the concept was falling into disfavor in America. In
1950, Lashley championed the European ethologists' views of fixed
action patterns though he himself preferred the term instinct. His
article on instinct in the Encyclopaedia Britannica of 1956 is
especially noteworthy.
6. The next chapter, entitled 'Issues of Priority, Opinion and
Criticism', includes:
i. a reconsideration of Lashley's obsession with theoretical
criticism in his later years, as alleged by Hebb.
ii. an interpretation of the meaning of Lashley's refusal of Hebb's
offer to coauthor the 1949 volume with him.
iii. the history of the reverberatory circuit in the psychological
literature, and questions of priority as far as the integration of
the reverberatory circuit into neuropsychological theory is
concerned.
iv. the fact that Lashley failed to acknowledge data and theory
that were unfavorable to his views, during his search for the
engram. This is documented.
v. Lashley's opinion of Hebb's theories was never known because
Lashley hardly ever spoke of them. But Lashley's 1947 review of
Hebb's manuscript-in-progress is revealing in this regard.
Revealing as well is Lashley's letter of congratulations to Hebb
after publication of his 1949 monograph.
Finally, the personal relationship of Lashley, the teacher, and Hebb,
the student, is delineated.
7. The next chapter, titled 'Hebb's The Organization of Behavior 50
Years After Publication', offers a contemporary view of Hebb's enduring
contributions to neuropsychological theory. Hebb bolstered his theories
with the following facts:
i. adults seem to be able to sustain brain injury with fewer
permanent consequences than can infants and children;
ii. learning in children is much more difficult compared to similar
learning in adults.
Hebb further argued that:
iii. distinctions should be made between primitive unity,
non-sensory figure and identity in perception;
iv. stimulus equivalence and generalization are learned in early
life;
v. the ratio of association cortex to sensory cortex should be
considered in phylogenetic development;
vi. the evidence of post-tetanic potentiation supports the
importance of the Hebb synapse in learning (this phenomenon was
described after the 1949 monograph was published but it found its
way into Hebb's later writings);
vii. there is a distinction between intelligence A (innate
potential) and intelligence B (achievement);
viii. following Tolman, Hebb introduced a new way of thinking about
neuropsychological problems in his 1960 presidential address to
APA. That discourse is today named cognitive psychology;
ix. later research on the stabilized retinal image supported cell
assembly theory.
8. The Left and Right Cerebral Hemispheres reviews the case of Alex, a
nine year old boy whose left hemisphere was removed for the relief of
intractable epileptic seizures. Though he never learned to speak before
surgery, Alex began to show remarkable gains in speech and language and
in cognitive skills in general. Alex's postoperative achievements
challenge the widely held view, shared by Hebb, that early childhood is
a particularly critical period for the acquisition of cognitive skills.
It must be concluded that clearly articulated, well-structured, and
appropriate language can be acquired for the first time as late as nine
years of age with the right hemisphere alone. Hebb and Lashley did no
live to see this case. My guess is that Hebb would have had great
difficulty in explaining Alex's achievements, but Lashley would have
chuckled and muttered in so many words, 'You see, not only do you have
reduplication of the memory trace within a hemisphere but also between
hemispheres.'
9. The next chapter is entitled, 'A Comparison of Lashley and Hebb on
the Concepts of Attention and Stimulus Generalization'. On the concept
of attention, Lashley took off from his observations of attempted
solutions in rats during the learning of the maze. It was Spence's
concession on this matter that persuaded Lashley that he had bested the
neo-behaviorists on the continuity-discontinuity debate. In the 1942
paper (reprinted in this volume), Lashley argued that a pattern of
excitation in the cortex in the form of a reverberatory circuit may
form a relatively stable and permanent foundation, modifying the
effects of later stimulation, as attention determines the selection of
stimuli. These ideas precede Hebb's formulation of the central
autonomous process by some seven years. And then in the Vanuxem
Lectures of 1952, Lashley went way beyond Hebb when he introduced the
ideas of a priming or pre-setting of circuits based upon the spacing of
the end-feet on the post-synaptic cell. Hebb was by far the more
accomplished writer and so, with the publication of his monograph in
1949, he captured the attention of the neuropsychological community
with ideas that did not differ substantially from Lashley's.
10. However, on the matter of stimulus generalization their positions
were radically different. Lashley's position is nativistic stimulus
generalization, if it exists at all, is built into the organism. His
conception derived from his critique of the neo-Pavlovian view of a
gradient in stimulus similarity underlying stimulus generalization. His
discontinuity position on learning led him to write in 1946 'Stimulus
generalization is generalization only in the sense of failure to note
distinguishing charateristics of the stimulus or to associate them with
the conditioned reaction. A definite attribute of the stimulus is
abstracted and forms the basis of reaction; other attributes are either
not sensed or are disregarded. So long as the effective attribute is
present, the reaction is elicited as an all-or-none function of that
attribute. Other characteristics of the stimulus may be radically
changed without affecting the reaction' (Lashley and Wade, 1946). The
neo-Pavlovian gradient of similarity on a stimulus continuum is an
artifact of inattention. Such a stimulus generalization is
generalization by default.
11. Hebb's concept of stimulus generalization was developed in
connection with his delineation of the formation of the cell assembly
underlying the perception of a triangle. Hebb's contribution was to
perceptual theory. He proposed the startling idea that a simple figure
like an outline triangle is not perceived as a whole, innately, as
alleged by the gestaltists. He went on to show how the elements of line
and angle become integrated into a unified perception of a triangle. To
persuade the skeptical reader, Hebb introduced the idea of perceptual
identity, something that has to be learned. He then proposed a
mechanism involving neural fractionation and recruitment. Fractionation
eliminates the variable cells that are excited extramacularly. Macular
excitation, which is due to ocular fixation, remains constant despite
the variable angular size of the stimulus object.
12. In short, stimulus generalization emerges secondarily from the slow
development of each complex concept. And yet, there is some doubt
regarding the universality of stimulus generalization according to
Hebb. His theory cannot always predict stimulus generalization from the
learning of a simple discrimination. Take for example the learning to
discriminate a vertical from a horizontal line. In this case, the
stimuli belong to the category of primitive unity for which, unlike the
triangle, no learning is required, according to Hebb, to build a
unified percept. Nevertheless, our best guess is that, empirically,
after the initial learning to discriminate the two lines, the organism
would show stimulus generalization to a vertical rectangle vs. a
horizontal rectangle and even to a vertical row of circles vs. a
horizontal row of circles. Since there is no initial learning to build
a unified perception of the vertical and horizontal lines, it is
difficult to see how Hebb would derive the empirical data of stimulus
generalization in this case.
13. A late chapter of commentary is entitled, 'Lashley's Enduring
Legacy to Neuropsychological Theory'. A contemporary perspective is
offered in reviewing the concepts of vicarious functioning,
equipotentiality, reduplicated memory trace, the reverberatory
circuit. Lashley's lesson that synapses inactive during learning can
show the effects of learning is emphasized. Lashley's lesson was never
acknowledged by Hebb or any of his students. Lashley derided the use of
wiring diagrams in neuropsychological theory especially those derived
from computer technology. Neurons are live metabolizing cells, he
argued, not inert paths like copper wires. They interact at synapses,
which are not solder joints like soldered copper wires. The synaptic
contacts are variable. Furthermore, synaptic contacts may be excitatory
and/or inhibitory. Soldered wires are always excitatory and fixed. Both
are pathways to be sure but the differences between neurons and copper
wires far outnumber their similarities. Thus brain organization cannot
be modelled by circuit diagrams representing inert pathways.
14. An epilogue presents a number of personal vignettes of both Lashley
and Hebb. Lashley's career was reviewed earlier in some detail in
Orbach (1982). The most disturbing part of this story has to do with
Lashley's racism, as alleged by Weidman (1996). I would not have raised
this matter in a scholarly volume concerned with Lashley's
contributions to neuropsychological theory were it not for Weidman's
allegation that Lashley's racist attitudes influenced his theoretical
views. But, did these odious attitudes of Lashley affect his science? I
can attest to Lashley's anti-African-American attitudes, but I can find
no evidence that Lashley's racism colored his theories. A lifelong
student of genetics, Lashley had an abiding interest in the concept of
instinct and in the genetics of behavior in general. These facts must
have eluded Weidman. Both Hebb and Lashley were honored many times
during their lifetimes. It is especially noteworthy that Hebb was
appointed Chancellor of McGill University, and that he was nominated,
in 1965, for the Nobel Prize.
15. During his freshman year, at the age of 16, Lashley studied general
zoology and comparative anatomy with Albert M. Reese at the University
of West Virginia. Reese appointed him departmental assistant, at a
salary of $0.25 per hour. One of the new assistant's first tasks was to
sort out various materials in the basement. The result of this
assignment can best be expressed in Lashley's own words: 'Among them I
found a beautiful Golgi series of the frog brain. I took these to Reese
and proposed that I draw all of the connections between the cells. Then
we would know how the frog worked (sic!). It was a shock to learn that
the Golgi method does not stain all cells, but I think almost ever
since I have been trying to trace those connections' (Beach in Orbach,
1982). Only later did Lashley realize that functional variables such as
spatial and temporal summation, excitatory and inhibitory states, and
micro-movements of elements influencing synaptic contact need not be
represented microscopically. The lesson is that neurons are not inert
and static, like soldered wires. They are live metabolizing cells with
synaptic contacts that vary. If Lashley were alive today, there is no
doubt that he would continue to scold modern neuroscientists who still
have not become aware of the importance of this fact.
16. Part 2 of the book consists of nine of Lashley's major theoretical
papers reprinted in their entirety. These are listed in the References
below. Part 2 also includes Lashley's four Vanuxem Lectures given at
Princeton University in 1952, and published here for the first time. In
these lectures, Lashley referred to the anatomical observations of
Lorente de N and emphasized the neural net as the active neural unit in
the cerebral cortex. He introduced the idea of a neural priming or
presetting, concepts all highly reminiscent of Hebb's theorizing on the
central autonomous process and the cell assembly. The term neural
lattice was coined by Lashley in 1949. This term was discarded by Hebb
in his 1949 monograph in favor of cell assembly.
REFERENCES:
http://www.wabash.edu/depart/psych/Courses/Psych_81/LASHLEY.HTMhttp://www.archives.mcgill.ca/guide/volume2/gen01.htm#HEBB, DONALD OLDING
http://www.princeton.edu/~harnad/hebb.htmlhttp://www.cogsci.soton.ac.uk/bbs/Archive/bbs.amit.html
Hebb, D. O. (1949) The Organization of Behavior: a Neuropsychological
Theory. New York: Wiley.
Hebb, D. O. and Donderi, D.C. (1994) Textbook of Psychology, fourth
edition, revised. Dubuque, Iowa: Kendall/Hunt Publishing Company.
Hilgard, E. R. and Marquis, D. G. (1940) Conditioning and Learning,
NY: Appleton-Century.
Lashley, K. S. (1924) 'Studies of cerebral function in learning. VI.
The theory that synaptic resistance is reduced by the passage of the
nerve impulse.' Psychol. Rev., 31, 369-375.
Lashley, K. S. (1931) 'Mass action in cerebral function.' Science 73,
245-254.
Lashley, K. S. 'The problem of cerebral organization in vision.' Biol.
Symp, 1942, 7, 301-322.
Lashley, K. S. (1949) 'Persistent problems in the evolution of mind.'
Quart. Rev. Biol., 24, 28-42.
Lashley, K. S. (1950) 'In search of the engram.' In Symp. Soc. Exp.
Biol. No. 4, Cambridge, Eng.,: Cambridge Univ. Press.
Lashley, K. S. (1951) 'The problem of serial order in behavior.' In
Jeffress, L. A. (Ed.) Cerebral mechanisms in behavior, New York,
Wiley.
Lashley, K. S. (1952) Vanuxem Lectures delivered at Princeton
University in Feb. 1952. Untitled.
Lashley, K. S. (1954) 'Dynamic processes in perception.' In Adrian, E.
D. Bremer, F. and Jasper, H. H. (Eds.) Brain Mechanisms and
Consciousness. Illinois, Charles C. Thomas, 422-443.
Lashley, K. S. (1968) 'Cerebral organization and behavior.' In The
Brain and Human Behavior, Proc. Ass. Res. Nerv. Ment. Dis., 36, 1-18.
Lashley, K. S. and Wade, M. (1946) 'The Pavlovian theory of
generalization.' Psychol. Rev., 53, 72-87.
Lashley, K. S., Chow, K.-L, and Semmes, J., (1951) 'An examination of
the electrical field theory of cerebral integration.' Psychol. Rev.,
58, 123-136.
Orbach, J. (1982) Neuropsychology After Lashley: Fifty Years Since the
Publication of Brain Mechanisms and Intelligence. Hillsdale, NJ.:
Lawrence Erlbaum Associates.
Weidman, N. (1996) 'Psychobiology, progressivism, and the
anti-progressive tradition.' J. Hist. Biol, 29, 267-308.
Annak, akit illet:
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hely: ELTE TTK Lagymanyosi Campus
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ELTE University, 1518 Budapest, P.O. Box 32, Hungary
Phone/FAX: (36) 1 372 2924 email: gk(a)hps.elte.hu
http://hps.elte.hu/~gk ftp://hps.elte.hu
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Koch/Gobell/Roid: INDIVIDUAL DIFFERENCES IN COLOR STROOP
The target article below has just appeared in PSYCOLOQUY, a
refereed journal of Open Peer Commentary sponsored by the American
Psychological Association. Qualified professional biobehavioral,
neural or cognitive scientists are hereby invited to submit Open
Peer Commentary on it. Please email or see websites for
Instructions if you are not familiar with format or acceptance
criteria for PSYCOLOQUY commentaries (all submissions are
refereed).
To submit articles and commentaries or to seek information:
EMAIL: psyc(a)pucc.princeton.edu
URL: http://www.princeton.edu/~harnad/psyc.htmlhttp://www.cogsci.soton.ac.uk/psyc
AUTHORS' RATIONALE FOR SOLICITING COMMENTARY: We have found a
pattern of individual differences on the Stroop color-word test
that do not seem to be among those reported previously (MacLeod,
1991). Two separate attempts to identify the source of these
individual differences have failed, although we kept finding the
same patterns of responding. We hope the article will draw
attention to the need to examine individual differences in Stroop
processing and and that the Psycoloquy it elicits will help
identify their basis.
-----------------------------------------------------------------------
psycoloquy.99.10.025.stroop-differences.1.koch Thu Sep 16 1999
ISSN 1055-0143 (27 paragraphs, 29 references, 599 lines)
PSYCOLOQUY is sponsored by the American Psychological Association (APA)
Copyright 1999 Christopher Koch, Joetta Gobell, & Gale H. Roid
EXPLORING INDIVIDUAL DIFFERENCES IN STROOP PROCESSING WITH CLUSTER ANALYSIS
Target Article on Stroop-Differences
Christopher Koch, Joetta Gobell, & Gale H. Roid
Department of Psychology
George Fox University
414 N. Meridian St.
Newberg OR 97132 USA
ckoch(a)georgefox.edu
http://www.georgefox.edu/people/faculty/ckoch/
ABSTRACT: A relatively small number of studies of the Stroop task
has examined individual differences in age, sex, hemispheric
processing, and language. The amount of interference is the primary
dependent measure in most studies, not the factors that contribute
to the interference. In the present target article, cluster
analysis is used to identify groups of participants who respond
similarly on the Stroop task. Integrated color-word Stroop stimuli
were presented for varying durations in the first study.
Significant individual differences were found. A cluster analysis
identified two groups of subjects. One group responded consistently
across durations and conditions while the other responded more
erratically. Potential sources of individual differences were
examined in a second study. 120 subjects were given the Color and
Word Test along with selected subtests of the Stanford Binet
Intelligence Test, age appropriate Wechsler tests, and the Detroit
Tests of Learning Aptitude. Again, cluster analysis found two
groups of subjects. The group with higher scores on visual
reasoning and short-term memory produced more interference.
KEYWORDS: cluster analysis, individual differences, short-term
memory, Stroop interference, visual reasoning
PSYCOLOQUY CALL FOR BOOK REVIEWERS
Below is the Abstract of the Precis of "The g Factor" by Arthur Jensen.
This book has been selected for multiple review in PSYCOLOQUY. If you
wish to submit a formal book review please write to
psyc(a)pucc.princeton.edu indicating what expertise you would bring to
bear on reviewing the book if you were selected to review it.
(If you have never reviewed for PSYCOLOQUY or Behavioral & Brain
Sciences before, it would be helpful if you could also append a copy of
your CV to your inquiry.) If you are selected as one of the reviewers
and do not have a copy of the book, you will be sent a copy of the book
directly by the publisher (please let us know if you have a copy
already). Reviews may also be submitted without invitation, but all
reviews will be refereed. The author will reply to all accepted
reviews.
The Full Precis of the book is available at these URLs (bot note that
the Reviews are to be of the BOOK, not the Precis: :
http://www.cogsci.soton.ac.uk/cgi/psyc/newpsy?10.023
or
ftp://ftp.princeton.edu/pub/harnad/Psycoloquy/1999.volume.10/
psyc.99.10.023.intelligence-g-factor.1.jensen
Full Psycoloquy book review instructions at:
http://www.princeton.edu/~harnad/psyc.htmlhttp://www.cogsci.soton.ac.uk/psycoloquy/
Relevant excerpts:
Psycoloquy reviews are of the book not the Precis. Length should be
about 200 lines [c. 1800 words], with a short abstract (about 50
words), an indexable title, and reviewer's full name and
institutional address, email and Home Page URL. All references that
are electronically accessible should also have URLs.
AUTHOR'S RATIONALE FOR SOLICITING COMMENTARY
The g factor arises from the empirical fact that scores on a large
variety of independently designed tests of extremely diverse cognitive
abilities all turn out to be positively correlated with one another.
The g factor appears to be a biological property of the brain, highly
correlated with measures of information-processing efficiency, such as
working memory capacity, choice and discrimination reaction times, and
perceptual speed. It is highly heritable and has many biological
correlates, including brain size, evoked potentials, nerve conduction
velocity, and cerebral glucose metabolic rate during cognitive
activity. It remains to investigate and explain its neurobiological
basis. Commentary is invited from psychometricians, statisticians,
geneticists, neuropsychologists, psychophysiologists, cognitive
modellers, evolutionary psychologists and other specialties concerned
with cognitive abilities, their measurement, and their cognitive and
neurobiological basis.
psycoloquy.023.intelligence-g-factor.1.jensen Wed Sep 15 1999
ISSN 1055-0143 (70 paragraphs, 12 references, 905 lines)
PSYCOLOQUY is sponsored by the American Psychological Association (APA)
Copyright 1999 Arthur Jensen
Precis of :
THE G FACTOR: THE SCIENCE OF MENTAL ABILITY
[Praeger, 1998 xiv + 648 pp. ISBN 0-275-96103-6 ISSN 1063-2158]
Arthur R. Jensen
Graduate School of Education
University of California, Berkeley
Nesnejar(a)aol.com
ABSTRACT: The g factor is the highest-order common factor that can
be extracted in a hierarchical factor analysis from a large battery
of diverse tests of various cognitive abilities. It is the most
important psychometric construct in the study of individual
differences in human cognitive abilities. Since its discovery by
Spearman in 1904, the g factor has become so firmly established as
a major psychological construct in terms of psychometric and factor
analytic criteria that further research along these lines is very
unlikely either to disconfirm the construct validity of g or to add
anything essentially new to our understanding of it. In fact, g,
unlike any of the primary, or first-order, factors revealed by
factor analysis, cannot be described in terms of the knowledge
content of cognitive test items, or in terms of skills, or even in
terms of theoretical cognitive processes. It is not essentially a
psychological or behavioral variable, but a biological one, a
property of the brain. But although not itself a cognitive ability,
g is what causes positive correlations among individual differences
in performance, even on cognitive tasks that differ greatly with
respect to sensory motor modality, brain modularity, and learned
cognitive skills and knowledge. The g factor derived from
conventional nonspeeded psychometric tests shows higher
correlations than any other factors independent of g with various
measures of information-processing efficiency, such as working
memory capacity, choice and discrimination reaction times, and
perceptual speed. A test's g loading is the best predictor of its
heritability and its sensitivity to inbreeding depression.
Psychometric g also has more direct biological correlates than any
other independent source of test variance, for example brain size,
brain evoked potentials, nerve conduction velocity, and the brain's
glucose metabolic rate during cognitive activity. The ultimate
arbiter among various "theories of intelligence" must be the
physical properties of the brain itself. The current frontier of g
research is the investigation of the anatomical and physiological
features of the brain that cause g. Research has reached the point
at which the only direction left in which to go is that presaged by
Spearman himself, who wrote that the final understanding of g must
"come from the most profound and detailed direct study of the human
brain in its purely physical and chemical aspects" (1927, p.403).
KEYWORDS: behavior genetics, cognitive modelling, evoked
potentials, evolutionary psychology, factor analysis, g factor,
heritability, individual differences, intelligence, IQ,
neurometrics, psychometrics, psychophyiology, skills, Spearman,
statistics
The Full Precis of the book is available at these URLs (bot note that
the Reviews are to be of the BOOK, not the Precis: :
http://www.cogsci.soton.ac.uk/cgi/psyc/newpsy?10.023
or
ftp://ftp.princeton.edu/pub/harnad/Psycoloquy/1999.volume.10/
psyc.99.10.023.intelligence-g-factor.1.jensen
Full Psycoloquy book review instructions at:
http://www.princeton.edu/~harnad/psyc.htmlhttp://www.cogsci.soton.ac.uk/psycoloquy/
Relevant excerpts:
Psycoloquy reviews are of the book not the Precis. Length should be
about 200 lines [c. 1800 words], with a short abstract (about 50
words), an indexable title, and reviewer's full name and
institutional address, email and Home Page URL. All references that
are electronically accessible should also have URLs.