'Theory Of Mind' And Executive Functions, Brain 
Abstract: There have been recent suggestions that the
amygdala may be involved in the development or mediation of
`theory of mind'. We report a patient, B.M., with early or
congenital left amygdala damage who, by adulthood, had received
the psychiatric diagnoses of schizophrenia and Asperger's
syndrome. We conducted a series of experimental investigations to
determine B.M.'s cognitive functioning. In line with his
diagnoses, B.M. was found to be severely impaired in his ability
to represent mental states. Following this, we conducted a second
series of studies to determine B.M.'s executive functioning. In
the literature, there have been frequent claims that theory of
mind is mediated by general executive functioning. B.M. showed no
indication of executive function impairment, passing 16 tests
assessing his ability to inhibit dominant responses, create and
maintain goal-related behaviours, and temporally sequence
behaviour. The findings are discussed with reference to models
regarding the role of the amygdala in the development of theory of
mind and the degree of dissociation between theory of mind and
executive functioning. We conclude that theory of mind is not
simply a function of more general executive functions, and that
executive functions can develop and function on-line,
independently of theory of mind. Moreover, we conclude that the
amygdala may play some role in the development of the circuitry
mediating theory of mind.
-
Excerpt: A new study has found the strongest evidence
yet that what sets humans apart from other primates may be found
in the brain's frontal lobes, particularly in an area the size of
a "billiard ball" called the right prefrontal cortex.
(…)
Understanding the mental processes of others -- mentalizing
-- is the basis of our socialization and what makes us human. It
gives rise to our capacity to feel empathy, sympathy, understand
humor and when others are being ironic, sarcastic or even
deceptive. It's a "theory of mind" that has been associated with
the frontal lobes, but until now scientists have had difficulty
demonstrating this ability to specific regions of the brain.
What is exciting about this study, according to Dr. Timothy
Shallice of the Institute of Cognitive Neuroscience at University
College London, is that the Rotman study came at this challenge
with two different testing methods and both generated similar
compelling evidence to show that these higher cognitive functions
in humans are "localizable" to a specific region within the
frontal lobes. Dr. Shallice wrote the lead editorial in BRAIN.
Dr. Stuss and his research colleagues tested patients who
had damage to various parts of the frontal lobes, and other areas
of the brain as well. The selective impairment in only some
patients provided the ability to precisely localize those regions
that are necessary when specific mentalizing tasks are performed.
Co-authors on the paper with Dr. Stuss, who is director of The
Rotman Research Institute at Baycrest, were Dr. Gordon Gallup,
Department of Psychology, State University of New York at Albany;
and Dr. Michael Alexander, Memory Disorders Research Centre at
Boston University and Department of Neurology, Harvard University.
"In our study, we've shown that the frontal lobes were the
most critical region for visual perspective taking, and the
inferior medial prefrontal region, particularly for the right, for
detecting deception," says Dr. Stuss. Visual perspective taking is
the ability to empathize or identify with the experience of
another person.
It has long been known that some patients with frontal lobe
damage have significantly changed personalities. What is important
about the study is that it helps families, friends and caregivers
of the patient to appreciate and understand a very important
reason why this occurs. This deficit in mentalizing can affect
social cognition which is important in everyday human
interactions. For example, patients with damage in the specific
frontal area are often less empathetic and sympathetic, and they
miss social cues which lead to inappropriate judgements.
In the study, 32 adults with lesions in frontal and
non-frontal brain regions, most commonly as a result of stroke,
and a control group of 14 healthy adults, underwent two seemingly
very simple tests. Both tasks required participants to guess which
coffee cup a ball was hidden under. Participants sat across a
table from the experimenter and a table curtain was used on some
occasions to conceal which cup the experimenter hid the ball
under. The participant was asked to point to the correct cup.
The Frontal Lobes Are Necessary For 'Theory Of Mind', Brain
Abstract: Patients with limited focal frontal and
nonfrontal lesions were tested for visual perspective taking
and detecting deception. Frontal lobe lesions impaired the
ability to infer mental states in others, with dissociation of
performance within the frontal lobes. Lesions throughout the
frontal lobe, with some suggestion of a more important role for
the right frontal lobe, were associated with impaired visual
perspective taking. Medial frontal lesions, particularly right
ventral, impaired detection of deception. The former may
require cognitive processes of the lateral and superior medial
frontal regions, the latter affective connections of the
ventral medial frontal with amygdala and other limbic
regions.
Time Scales In Motor Learning And Development, Psychological Review
Abstract: A theoretical framework based on the concepts and
tools of nonlinear dynamical systems is advanced to account for
both the persistent and transitory changes traditionally shown for
the learning and development of motor skills. The multiple time
scales of change in task outcome over time are interpreted as
originating from the system's trajectory on an evolving attractor
landscape. Different bifurcations between attractor organizations
and transient phenomena can lead to exponential, power law, or
S-shaped learning curves. This unified dynamical account of the
functions and time scales in motor learning and development offers
several new hypotheses for future research on the nature of change
in learning theory. Reprint requests can be sent to Gottfried
Mayer-Kress
Superior Auditory Spatial Tuning In Conductors, Nature
Excerpts: Thomas Münte of the University of Magdeburg,
Germany, and colleagues compared conductors' sonic accuracy with
that of classical pianists and non-musicians, all of whom had on
average more than 15 years of professional experience.
Münte's team found that conductors can focus their hearing
more sharply even than other professional musicians.
(…)
Münte's team sat subjects before an array of six
speakers, three in front of the subject, and three off to one
side. Through these were played bursts of pink
noise(…).
Find That Tune, Nature
Excerpts: Seven classical-music conductors (mean age, 45
yr; mean conducting experience, 19 yr; minimum, 6 yr), seven
pianists (mean age, 43 yr; mean professional playing
experience, 16 yr; minimum, 7 yr) and seven non-musicians (mean
age, 43 yr) were tested in a paradigm used originally to
demonstrate superior sound localization in congenitally blind
subjects(…)
From magnetoencephalographic recordings, the attention
effect is known to arise in the secondary auditory cortex, an
area also implicated from functional imaging.
-
Excerpt: They displayed some of their most adroit
manoeuvring in dramatic 'dogfights', in which one bat pursued
another. "The scope of echo processing needed to guide bats
through these high-speed aerial dogfights … is a positive
embarrassment for most current thinking about auditory coding of
echoes," say the researchers.
An understanding of how bats perform these feats could
produce technological spin-offs for sonar navigation and detection
equipment, Simmons' group suggests. Already bats' broad-band
(many-frequency) sonar system is emulated in mine-sweeping
technology.
-
Abstract: Infrared cameras and ultrasonic microphones
were used to record big brown bats (Eptesicus fuscus) flying in
natural conditions at night while they hunted for insects. As
expected, bats avoided obstacles while flying through
vegetation and intercepted flying prey in the open. But bats
also appeared to capture insects near and possibly on the
ground and near or in vegetation, flew low over water to drink,
and pursued each other in aerial "dogfights." In less than a
minute, the same bat often used echolocation for several
different tasks, showing a wider repertoire of sonar-guided
behavior than revealed by previous observations limited to
seeing bats flying against the evening sky or being
photographed in fixed fields-of-view.
- Versatility
Of Biosonar In The Big Brown Bat, Eptesicus
fuscus,
Simmons, J. A., Eastman, K. M., Horowitz, S.
S., O'Farrell, M. J. & Lee, D. N., Acoustics
Research Letters Online 2(1), 43-48
(2001).
Picking Out Odors, Science
The sense of smell is one of our most fundamental senses. The
representation of an odor is a fundamental challenge to
understanding how our brain works. Early work on rabbits by
Walter Freeman who observed spatio-temporal
pattern dynamics representing odors in the olfactory bulb could be
confirmed and generalized for zebra fish brains:
Odor representations in the olfactory bulb are not
stationary but change while the stimulus is present. Friedrich and
Laurent (p. 889
; see the Perspective by Yoshihara
et al.) recorded from mitral cells in the olfactory
bulb of the zebra fish. Responses of these neurons to odors became
progressively transformed during the time course of stimulus
presentation. This transformation was not due to sharpening of
individual mitral-cell tuning profiles. Instead, odor
representation appeared to become more evenly distributed at later
times during stimulation. Temporal patterning reduced the
similarity between ensemble activities and made each odor
representation more specific over time. These data provide an
important step in our understanding of how olfaction differs from
other sensory modalities.
Excerpt: A sense of smell (olfaction) is an essential
feature of most animal species, from insects and fish to mammals.
An enormous number of odorant molecules are recognized by odorant
receptors expressed on the surface of sensory neurons in the
olfactory epithelium (1). Each neuron carries only one type of
odorant receptor, and this receptor is activated by a range of
odorants with similar structures. The axons of olfactory neurons
send odor information encoded as electrical impulses to the
olfactory bulb.
Odor Representation By Slow Temporal Patterning Of Mitral Cell Activity, Science
Abstract: Mitral cells (MCs) in the olfactory bulb (OB)
respond to odors with slow temporal firing patterns. The
representation of each odor by activity patterns across the MC
population thus changes continuously throughout a stimulus, in
an odor-specific manner. In the zebrafish OB, we found that
this distributed temporal patterning progressively reduced the
similarity between ensemble representations of related odors,
thereby making each odor's representation more specific over
time. The tuning of individual MCs was not sharpened during
this process. (…)
-
Excerpt: Spatial pattern formation is the primary task of
the olfactory receptor layer, and pattern classification and
interpretation are the primary tasks of the central olfactory
system. The parallel distributed nonlinear feedback model that
is described here, operating in the chaotic domain, has been
shown to perform pattern classification of industrial data
(Davis and Eichenbaum 1991; Yao, et al. 1991). It can learn a
new class of inputs in one or a few trials lasting 200 msec of
simulated time, and it is virtually immune to background noise.
The most useful application for this biologically inspired
system may be to provide an interface between the real world
and finite state automata, in the way that the sensory cortices
interface between the environment and the limbic
system.
-
Abstract: OBJECTIVE: The authors examined the relationship
between treatment with clozapine and rates of arrest of psychotic
outpatients with criminal histories. METHOD: Patients who had been
given a DSM-IV psychotic diagnosis were selected from an urban
outpatient clinic database. Background checks performed on 360
patients identified 165 (45.8%) with positive criminal histories
in Massachusetts. The authors reviewed the charts of these
patients to determine several variables, including whether and
when they had received clozapine. A Poisson regression model was
used to regress arrest rates against the variables of age, sex,
onset of illness, birth cohort, and clozapine treatment. Risk
ratios (i.e., percent change in arrest rates) were then calculated
by computing the exponential of the Poisson regression
coefficients. RESULTS: The 165 patients included in the analysis
had a total of 1,126 arrests. The mean number of arrests was 6.8.
Differences were found between the 65 patients who received
clozapine and the 100 patients who did not in number of arrests,
sex, and onset of illness. The regression revealed significantly
higher arrest rate estimates associated with more recent birth
cohort (4.8%) and with onset of illness (64.6%) and lower arrest
rate estimates associated with higher levels of education (11.6%),
receiving clozapine (32.6%), and receiving clozapine during
specific periods of time (68.9%). CONCLUSIONS: Clozapine's effect
on arrest rates in this group of patients is large enough to
warrant further investigation. The data indicate that clozapine
may reduce recidivism in subjects with criminal histories who are
in need of antipsychotic medication.
Simulation Sizes Up Web Structure, TRN News
Excerpt: With every hyperlink added to a Web page the shape
of the World Wide Web changes, but the problem of determining that
shape is trickier than just estimating the number of links and
mapping where they go.
Large, complex, evolving networks have proven difficult to
model statistically, and the Web is a particularly challenging
case.
A model and simulation that looks at how frequently links
are updated and at the relationship between outgoing and incoming
links promises to give a clearer picture of the Web's underlying
structure.
The model, developed by Slovenian researcher Bosiljka Tadic,
suggests that the shape of the Web is largely determined by how
and how often Web pages are updated, which in turn is determined
by the biases and policies of the people who update the pages. The
research also showed that the underlying structure of the Web is
still maturing.
Measuring IT Value Learning Center, DarwinMag
Excerpts: Measuring the value of IT investments was a
lot easier when the use of computers could be directly tied to
cost savings. For example, by automating bookkeeping, a computer
could eliminate eight bookkeepers from the payrolls. Today,
establishing value for IT is less straightforward, simply because
computing technology is everywhere. IT is no longer expected to
trim costs; it's now expected to enhance revenues and
profitability.
Why is measuring the value of IT so hard?
As IT has permeated organizations, measuring its direct
contribution to the bottom line has become more difficult. This is
because cost savings--primarily in the form of headcount reduction
and productivity improvements--were gains that were achieved early
on in a system's lifecycle. It's fairly easy to calculate the
value of eliminating salaried positions, but how to determine
value from an ability to close the books faster with fewer errors?
Similarly soggy ground surrounds systems that are designed to help
customer retention, improve product development, enhance knowledge
sharing and speed time-to-market. (…)
New Gnutella: Why It'll Be The Music Industry's Next Worst Nightmare, ZDNet
Excerpts: Gnutella is that other music-swapping
technology. The hard-to-use, also-ran to Napster. Well, now Coop
says a new Windows client version called Bearshare has him singing
a new song about Gnutella. And he'll tell you how, as a result,
the days of music swapping have hardly come to an end.
(…)Unlike Napster, Gnutella, which was born last March,
was not an address or a company. You couldn't serve it with legal
papers or picket outside its office. There was no there, there. In
this network of distributed intelligence, all you needed to do was
connect with a host. At that point, you were off to the races,
interacting with other nodes on the oh-so-decentralized Gnutella
universe. It was just so god-awful clunky to use that you had to
be a real glutton for punishment to suffer through the
process.
-
Excerpt: What's missing might turn out to be as
important as what's actually there in uncovering the roots of the
mammalian tree of life.
A team of biologists led by Mark Springer at the University
of California, Riverside and including Ronald DeBry of the
University of Cincinnati report in the Feb. 1 issue of Nature that
an intensive analysis of DNA sequences provides strong support for
a grouping Springer dubs "Afrotheria." The group includes a
variety of placental mammals from elephants to elephant shrews.
And add in aardvarks, manatees, and hyraxes to boot.
"One of the problems with mammal phylogenies is there hasn't
been a lot known," explained DeBry. "We were searching for the
basic outline of the tree of life."
Traditional phylogenies, or evolutionary trees, were based
on fossil evidence and physical similarities. To complicate things
further, there was a huge explosion of mammalian groups right
after dinosaurs went extinct.
"Finding the base of the tree has been difficult," said
DeBry. "There are lots and lots of questions."
Over the last 10 years, DNA studies have confirmed some
patterns proposed by those studying fossil evidence and physical
similarities. Other DNA studies turned up new and unexpected
relationships. The picture quickly got muddier and muddier.
"What we needed was a BIG data set," said DeBry. "Our data
set has six different genes and 8600 base pairs." Two of the genes
are found in mitochondrial DNA. The other four are found in the
chromosomes of the nucleus, including BRCA-1, commonly known as
the breast cancer gene.
Springer, DeBry and the other co-authors report that a
specific deletion of nine base pairs in BRCA-1 is shared by 12
groups of placental mammals. These are the groups Springer puts
together in "Afrotheria."
In addition, the exhaustive comparison helps to answer a
more recent question: How closely are rabbits and guinea pigs
related to rodents? The results in Nature indicate those groups
should remain together, in contrast to previously published
molecular results.
"Our data show a clearer picture," said DeBry. "The rodents,
including the guinea pig, belong together. And rabbits probably do
go with rodents."
On the other hand, a group known as Archonta should be split
apart according to Springer et al. "The molecular data are really
convincing that this isn't a group," said DeBry. "Bats are
somewhere completely different. They're closer to pigs and cows
than rodents and primates. Micro- and mega-bats go together with
hedgehogs."
If this is starting to sound a bit confusing, the biologists
have a very simple explanation for the divergence and resulting
evolutionary tree. The relationships which evolved closely
parallel the movement of continental land masses during geologic
time.
That's why Springer named one group Afrotheria for its
African origins and another Laurasiatheria after the land mass
which gave rise to North America, Europe and Asia.
"Our results give a really strong division right at the base
of the tree," noted DeBry. "Where did each group originate? One in
the southern hemisphere and the other in the northern hemisphere.
On the classic trees, the northern and southern groups are mixed
up."
Geological evidence supports the phylogenies as well.
Mammals first appeared in the fossil record about the time
continents were splitting apart. This would give the different
groups separate evolutionary histories, which is documented in the
DNA analyses. "The DNA sequences tell us a nice biogeographic
story," said DeBry. "We're not the first to see these
relationships, but the evidence really hammers home the point that
there is a group from Africa that is closely related."
- Biologists
Propose New Grouping for Mammals: Key Deletion Offers
Evidence for
"Afrotheria", U.
Cincinnati , Science
Daily News,
01/02/02
- Parallel
Adaptive Radiations In Two Major Clades Of Placental
Mammals, O
Madsen, M Scally, C J Douady, D J Kao, R W Debry, R
Adkins, H M Amrine, M J Stanhope, W W De Jong & M
S Springer, Nature 409, 610 - 614 (2001)
- Molecular
Phylogenetics And The Origins Of Placental
Mammals, W J
Murphy, E Eizirik, W E Johnson, Y P Zhang, O A Ryder,
& S J O'brien, Nature 409, 614 - 618 (2001)
Is The Genome The Secular Equivalent Of The Soul?, Science
Excerpt: The notion that the genome contains the blueprint
of human nature is akin to an important outlook within Western
metaphysics that interprets all living organisms as having
"souls," which determine their characteristic traits. From this
perspective, the human soul is viewed as encapsulating the human
essence. This convergence of ideas is perhaps not so surprising.
Max Delbrück, a 20th-century pioneer of molecular biology,
noted how the notion of a genetic program (borrowed by molecular
biologists from the fledgling computer sciences) had an uncanny
kinship with the Aristotelian concept of eidos, the organizing
principle inherent in every living thing.
Scale Dependence In Plant Biodiversity, Science
The relation between species richness and area is an
important component of ecological studies. Crawley and Harral
(p.
864 ) provide detailed evidence that the relation
varies with spatial scale, using data on plant species gathered at
different spatial scales in Britain ranging from 0.01 square meter
to 1000 square kilometers. Slopes of the species-area relation
(logarithm of species richness versus logarithm of area) were
steepest at intermediate scales, where the matrix of habitats with
distinct floras tends to maximize richness in any given area. The
shallowest slopes were at the smallest spatial scales, where
individual plants would be expected to interact strongly with each
other, and at the largest scales, where few new habitats are
added.
Excerpt: The relationship between the number of species
and the area sampled is one of the oldest and best-documented
patterns in community ecology. Several theoretical models and
field data from a wide range of plant and animal taxa suggest that
the slope, z, of a graph of the logarithm of species richness
against the logarithm of area is roughly constant, with z 0.25. We
collected replicated and randomized plant data at 11 spatial
scales from 0.01 to 108 square meters in Great Britain which show
that the slope of the log-log plot is not constant, but varies
systematically with spatial scale, and from habitat to habitat at
the same spatial scale.
Links & Snippets
SFI Working Papers
These references can be found in http://www.santafe.edu/sfi/publications/01wplist.html:
- 01-01-001 On the Evolution of
Polygamy: A Theoretical Examination of the Polygamy
Threshold Model , Susan Ptak and Michael
Lachmann
- 01-01-002 The Role of Begging and
Sibling Competition in Foraging Strategies of Nestlings
Miguel A. Rodriguez-Girones, Magnus Enquist, and Michael
Lachmann
- 01-01-003 Social Capital and
Community Governance , Samuel Bowles and Herbert
Gintis
- 01-01-004 Incentive-Enhancing
Preferences: Personality, Behavior, and Earnings ,
Samuel Bowles, Herbert Gintis, and Melissa
Osborne
- 01-01-005 The Inheritance of Economic
Status: Education, Class, and Genetics , Samuel Bowles
and Herbert Gintis
- 01-01-006 Landscapes on Spaces of
Trees , Oliver Bastert, Dan Rockmore, Peter F. Stadler,
and Gottfried Tinhofer
- 01-01-007 Cooperation, Reciprocity
and Punishment in Fifteen Small-scale Societies , Joseph
Henrich, Robert Boyd, Samuel Bowles, Colin Camerer, Ernst
Fehr, Herbert Gintis, and Richard McElreath
Announcements
- The
Evolution of Strong
Reciprocity, Sam
Bowles, Santa Fe Institute, Santa Fe, New Mexico,
01/03/9-11:
- Self-Organized
Complexity in the Physical, Biological and Social
Sciences, Arthur M.
Sackler Colloq. of the Natl. Acad. Sc., 01/03/23-24, Irvine,
CA
- SFI Workshop on The
Internet as a Large-Scale Complex System"
chaired by Kihong Park
(Purdue University) and Walter Willinger (AT&T
Labs-Research), 01/03/29-31
- SFI Workshop on Complexity
- Unifying Themes for the Sciences and New Frontiers for
Mathematics, Max Planck
Institute for Mathematics in the Sciences, Leipzig, Germany,
chaired by Suzanne Dulle, Ellen Goldberg, Juergen Jost,
01/05/14-18
- SFI Workshop on Hierarchies
and Scale, chaired by Craig
Allen, C.S. Holling, Garry Peterson, 01/05/17-19
- SFI Graduate Workshop in
Computational
Economics, chaired by John
Miller and Scott Page, 01/07/15-28
- SFI Complex
Systems Summer School, Santa
Fe, co-directed by Ray Goldstein, Melanie Mitchell, and Lynn
Nadel, 01/06/10-07/07
- SFI Complex
Systems Summer School,
Budapest, co-directed
by Melanie Mitchell and Imre Kondor,
01/07/16-08/10
- SFI Workshop on Poverty
Traps," chaired by Sam
Bowles, 01/07/20-22
- SFI
Summer Workshop: Mathematical Models in Molecular and
Cellular Biology, Lee Segel,
Santa Fe Institute, Santa Fe, New Mexico,
01/07/29-08/10
- 11th
Annual International Conference The Society For Chaos Theory
in Psychology & Life
Sciences, Madison, WI, USA,
01/08/3-6
- SFI Workshop on Economic
Inequality and Economic
Sustainability, chaired by
Sam Bowles, 01/09/21-23
- Interdis.
Appl. of Ideas from Nonext. Stat. Mech. &
Thermodyn., M. Gell-Mann, C.
Tsallis, Santa Fe Institute, Santa Fe, NM,
01/10/1-5
- Workshop on Intergenerational
Inequality, chaired by Sam
Bowles, 01/10/19-21
- Chalmers
University of Technology in
Goteborg, Sweden, offers an
international Master's program in complex adaptive systems
starting in September 2001
