2,196 research outputs found

    Attention gates visual coding in the human pulvinar.

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    The pulvinar nucleus of the thalamus is suspected to have an important role in visual attention, based on its widespread connectivity with the visual cortex and the fronto-parietal attention network. However, at present, there remain many hypotheses on the pulvinars specific function, with sparse or conflicting evidence for each. Here we characterize how the human pulvinar encodes attended and ignored objects when they appear simultaneously and compete for attentional resources. Using multivoxel pattern analyses on data from two functional magnetic resonance imaging (fMRI) experiments, we show that attention gates both position and orientation information in the pulvinar: attended objects are encoded with high precision, while there is no measurable encoding of ignored objects. These data support a role of the pulvinar in distractor filtering--suppressing information from competing stimuli to isolate behaviourally relevant objects

    Better Ballots

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    Literacy tests to gain access to the polls were banned in the United States in 1965 with the passage of the Voting Rights Act.99 But in November 2008, eight years after an election debacle of historic proportions, millions of voters across the United States will face a literacy test of a different sort after they've stepped into the voting booth. Their intended choices may be recorded only if they can understand instructions written at a high reading level, often using legal and election terminology. And they will only be counted if they successfully navigate ballot designs that are needlessly complicated, where candidates for the same offi ce may be listed on multiple columns or pages, or different contests are inconsistently formatted. As we have tried to demonstrate in this report, ballot design and instructions can have a huge impact on election results. We sampled some of the more "high profi le" ballot design disasters over the last several years; this is not a comprehensive analysis of the cost of poor ballot design on elections and votes counted. But, the examples illustrate how dramatically poor ballot design can affect vote totals -- particularly when a number of design fl aws appear on the same ballot. Not surprisingly, when these mistakes affected many ballots (by appearing on a signifi cant percentage of the ballots in large counties like Los Angeles or Palm Beach, or on most of the ballots in a particular state), tens of thousands -- and sometimes hundreds of thousands -- of votes in a single federal or statewide race have been lost. This does not even include the voters who may have been so confused by a ballot design that they cast their ballot for a candidate for whom they did not intend to vote (for obvious reasons, it is far more diffi cult to determine this than to know when a voter failed to successfully cast a vote at all). Better ballot design will make it far more likely that the preferred candidates of all voters will be declared winners of their contests. Palm Beach County 2000 should have been a wake-up call to legislators, election offi cials, and watchdog groups that ensuring good ballot design is a critical election administration issue that needs to be systematically addressed. Unfortunately, for the last eight years, it has continued to be largely ignored. The predictable result has disproportionately affected low-income and elderly voters, and thrown several important elections into turmoil. The good news is that there is still time before November 2008 to ensure that ballot design fl aws do not throw the results of another closely contested race into doubt, as has happened in several federal and state races in the last decade. And unlike changes to equipment (which, there is no question, could make systems more secure, accessible and usable), improving ballot design and instructions is possible for little or no cost, and a relatively small-scale investment of time

    Constitutional Law - State Action - Racial Discrimination - Taxation - Charitable Deduction - Foundation

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    The United States Court of Appeals for the Second Circuit has held that a private foundation\u27s practice of racial discrimination could be, because of its tax-exempt status and other government contracts, state action sufficient to invoke the prohibitions of the fourteenth amendment. Jackson v. Statler Foundation, 496 F.2d 623 (2d Cir. 1974)

    Differentiating the absolutely continuous invariant measure of an interval map f with respect to f

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    Let the map f:[1,1][1,1]f:[-1,1]\to[-1,1] have a.c.i.m. ρ\rho (absolutely continuous ff-invariant measure with respect to Lebesgue). Let δρ\delta\rho be the change of ρ\rho corresponding to a perturbation X=δff1X=\delta f\circ f^{-1} of ff. Formally we have, for differentiable AA, δρ(A)=n=0ρ(dx)X(x)ddxA(fnx) \delta\rho(A)=\sum_{n=0}^\infty\int\rho(dx) X(x){d\over dx}A(f^nx) but this expression does not converge in general. For ff real-analytic and Markovian in the sense of covering (1,1)(-1,1) mm times, and assuming an {\it analytic expanding} condition, we show that λΨ(λ)=n=0λnρ(dx)X(x)ddxA(fnx)\lambda\mapsto\Psi(\lambda)=\sum_{n=0}^\infty\lambda^n \int\rho(dx) X(x){d\over dx}A(f^nx) is meromorphic in C{\bf C}, and has no pole at λ=1\lambda=1. We can thus formally write δρ(A)=Ψ(1)\delta\rho(A)=\Psi(1).Comment: 10 pages, plain Te
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