1,736 research outputs found
Evolutionary game dynamics of controlled and automatic decision-making
We integrate dual-process theories of human cognition with evolutionary game
theory to study the evolution of automatic and controlled decision-making
processes. We introduce a model where agents who make decisions using either
automatic or controlled processing compete with each other for survival. Agents
using automatic processing act quickly and so are more likely to acquire
resources, but agents using controlled processing are better planners and so
make more effective use of the resources they have. Using the replicator
equation, we characterize the conditions under which automatic or controlled
agents dominate, when coexistence is possible, and when bistability occurs. We
then extend the replicator equation to consider feedback between the state of
the population and the environment. Under conditions where having a greater
proportion of controlled agents either enriches the environment or enhances the
competitive advantage of automatic agents, we find that limit cycles can occur,
leading to persistent oscillations in the population dynamics. Critically,
however, these limit cycles only emerge when feedback occurs on a sufficiently
long time scale. Our results shed light on the connection between evolution and
human cognition, and demonstrate necessary conditions for the rise and fall of
rationality.Comment: 9 pages, 7 figure
Optimal distillation of a GHZ state
We present the optimal local protocol to distill a
Greenberger-Horne-Zeilinger (GHZ) state from a single copy of any pure state of
three qubits.Comment: RevTex, 4 pages, 2 figures. Published version, some references adde
Categorification of persistent homology
We redevelop persistent homology (topological persistence) from a categorical
point of view. The main objects of study are diagrams, indexed by the poset of
real numbers, in some target category. The set of such diagrams has an
interleaving distance, which we show generalizes the previously-studied
bottleneck distance. To illustrate the utility of this approach, we greatly
generalize previous stability results for persistence, extended persistence,
and kernel, image and cokernel persistence. We give a natural construction of a
category of interleavings of these diagrams, and show that if the target
category is abelian, so is this category of interleavings.Comment: 27 pages, v3: minor changes, to appear in Discrete & Computational
Geometr
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The evolution and devolution of cognitive control : the costs of deliberation in a competitive world
Dual-system theories of human cognition, under which fast automatic processes can complement or compete with slower deliberative processes, have not typically been incorporated into larger scale population models used in evolutionary biology, macroeconomics, or sociology. However, doing so may reveal important phenomena at the population level. Here, we introduce a novel model of the evolution of dual-system agents using a resource-consumption paradigm. By simulating agents with the capacity for both automatic and controlled processing, we illustrate how controlled processing may not always be selected over rigid, but rapid, automatic processing. Furthermore, even when controlled processing is advantageous, frequency-dependent effects may exist whereby the spread of control within the population undermines this advantage. As a result, the level of controlled processing in the population can oscillate persistently, or even go extinct in the long run. Our model illustrates how dual-system psychology can be incorporated into population-level evolutionary models, and how such a framework can be used to examine the dynamics of interaction between automatic and controlled processing that transpire over an evolutionary time scale
Bolometric luminosities and infrared properties of carbon stars in the Magellanic Clouds and the Galaxy
Broad band J, H, K photometry and narrow band CO and H_2O indices have been obtained for 89 luminous red stars in the Large Magellanic Cloud (LMC) and 21 in the Small Magellanic Cloud (SMC), chosen largely from the sample of Blanco, McCarthy, and Blanco. Most are known to be carbon stars, and their infrared properties are compared with new observations of 33 galactic carbon stars. The bolometric luminosity distributions of an unbiased sample of Magellanic Cloud carbon stars are compared with those predicted from evolutionary calculations by Renzini and Voli for double shell burning stars undergoing He shell flashes. The observed and theoretical distributions disagree markedly: nearly all the observed stars have lower luminosities than even the faintest
theoretical carbon star.
In addition, we find many fewer than expected high luminosity stars with initial mass greater than 3 M_â. Possible explanations for this include a steep initial mass function for intermediate mass stars, a star formation rate significantly higher in the past than at present, or a neglected physical effect, such as underestimation of the importance of mass loss. Nevertheless, it appears that the hypothesis that He shell flashes lead to a dredge-up of carbon into the envelope, which results in a carbon star, can be maintained, if dredging occurs after fewer shell flashes than are predicted by presently available stellar evolutionary calculations.
The colors and indices of the late M giants in the LMC field are similar to those of late M giants in the Galaxy.
The narrow band infrared data are interpreted qualitatively in terms of the effects of molecular band absorption, which also strongly influences the infrared broad band colors of carbon stars. The small differences in the color-color relationships of the SMC and LMC samples are consistent with the differences in heavy metal abundance between the LMC, SMC, and Galaxy
Functional Imaging of Decision Conflict
Decision conflict occurs when people feel uncertain as to which option to choose from a set of similarly attractive (or unattractive) options, with many studies demonstrating that this conflict can lead to suboptimal decision making. In this article, we investigate the neurobiological underpinnings of decision conflict, in particular, the involvement of the anterior cingulate cortex (ACC). Previous studies have implicated the ACC in conflict monitoring during perceptual tasks, but there is considerable controversy as to whether the ACC actually indexes conflict related to choice, or merely conflict related to selection of competing motor responses. In a functional magnetic resonance imaging study, we dissociate the decision and response phases of a decision task, and show that the ACC does indeed index conflict at the decision stage. Furthermore, we sho that it does so for a complex decision task, one that requires the integration of beliefs and preferences and not just perceptual judgments
Signatures of multi-TeV scale particles in supersymmetric theories
Supersymmetric particles at the multi-TeV scale will escape direct detection
at planned future colliders. However, such particles induce non-decoupling
corrections in processes involving the accessible superparticles through
violations of the supersymmetric equivalence between gauge boson and gaugino
couplings. In a previous study, we parametrized these violations in terms of
super-oblique parameters and found significant deviations in well-motivated
models. Here, we systematically classify the possible experimental probes of
such deviations, and present detailed investigations of representative
observables available at a future linear collider. In some scenarios, the
option and adjustable beam energy are exploited to achieve high
precision. It is shown that precision measurements are possible for each of the
three coupling relations, leading to significant bounds on the masses and
properties of heavy superparticles and possible exotic sectors.Comment: 37 pages including 17 figures, REVTe
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Neurocognitive therapeutics: from concept to application in the treatment of negative attention bias
There is growing interest in the use of neuroimaging for the direct treatment of mental illness. Here, we present a new framework for such treatment, neurocognitive therapeutics. What distinguishes neurocognitive therapeutics from prior approaches is the use of precise brain-decoding techniques within a real-time feedback system, in order to adapt treatment online and tailor feedback to individualsâ needs. We report an initial feasibility study that uses this framework to alter negative attention bias in a small number of patients experiencing significant mood symptoms. The results are consistent with the promise of neurocognitive therapeutics to improve mood symptoms and alter brain networks mediating attentional control. Future work should focus on optimizing the approach, validating its effectiveness, and expanding the scope of targeted disorders
Super-oblique corrections and non-decoupling of supersymmetry breaking
If supersymmetric partners of the known particles have masses at the
multi-TeV scale, they will not be directly discovered at planned future
colliders and decouple from most observables. However, such superpartners also
induce non-decoupling effects that break the supersymmetric equivalence of
gauge boson couplings and gaugino couplings through supersymmetric
analogues of the oblique corrections. Working within well-motivated theoretical
frameworks, we find that multi-TeV scale supersymmetric particles produce
deviations at the 1-10% level in the ratios . Such effects allow one
to bound the scale of kinematically inaccessible superpartners through
precision measurements of processes involving the accessible superparticles.
Alternatively, if all superpartners are found, significant deviations imply the
existence of highly split exotic supermultiplets.Comment: 18 pages, REVTeX, no figur
Living with the consequences of policy decisions: reactions to student lifestyles in the neighbourhood
A national (UK) policy to expand higher education has changed the demographic composition of communities in many university towns and cities and the social forces operating thereon. As the economy and services adapt, those already resident in such areas may be quite comfortable accommodating the changes. Those who are not may leave (exit/flight) or stay and either âhunker downâ (loyalty) or act to protect what it was they had come to value about the area (voice). The case examined here is that of a part of Leeds where the consequent âstudentificationâ prompted the exit of many residents, thereby making way for further students. Some residents, with strong roots in the area, remained loyal and it is their views, along with those of business people, councillors and others, that are examined in this paper. This study of reactions to student lifestyles was initially prompted by Cohenâs notion of âmoral panicâ that gradually revealed a contestation over the right to determine the character, the soul, of the area. In so doing it considers how, as soft or symbolic power ebbed, attempts were made by local residents to shape a policy response. However, in that arena too, the locus of control is shown to be elusive
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