3,131 research outputs found
The oculomotor resonance effect in spatial-numerical mapping.
We investigated automatic Spatial-Numerical Association of Response Codes (SNARC) effect in auditory number processing. Two experiments continually measured spatial characteristics of ocular drift at central fixation during and after auditory number presentation. Consistent with the notion of a spatially oriented mental number line, we found spontaneous magnitude-dependent gaze adjustments, both with and without a concurrent saccadic task. This fixation adjustment (1) had a small-number/left-lateralized bias and (2) it was biphasic as it emerged for a short time around the point of lexical access and it received later robust representation around following number onset. This pattern suggests a two-step mechanism of sensorimotor mapping between numbers and space - a first-pass bottom-up activation followed by a top-down and more robust horizontal SNARC. Our results inform theories of number processing as well as simulation-based approaches to cognition by identifying the characteristics of an oculomotor resonance phenomenon
Ocular drift along the mental number line.
We examined the spontaneous association between numbers and space by documenting attention deployment and the time course of associated spatial-numerical mapping with and without overt oculomotor responses. In Experiment 1, participants maintained central fixation while listening to number names. In Experiment 2, they made horizontal target-direct saccades following auditory number presentation. In both experiments, we continuously measured spontaneous ocular drift in horizontal space during and after number presentation. Experiment 2 also measured visual-probe-directed saccades following number presentation. Reliable ocular drift congruent with a horizontal mental number line emerged during and after number presentation in both experiments. Our results provide new evidence for the implicit and automatic nature of the oculomotor resonance effect associated with the horizontal spatial-numerical mapping mechanism
Jet Trimming
Initial state radiation, multiple interactions, and event pileup can
contaminate jets and degrade event reconstruction. Here we introduce a
procedure, jet trimming, designed to mitigate these sources of contamination in
jets initiated by light partons. This procedure is complimentary to existing
methods developed for boosted heavy particles. We find that jet trimming can
achieve significant improvements in event reconstruction, especially at high
energy/luminosity hadron colliders like the LHC.Comment: 20 pages, 11 figures, 3 tables - Minor changes to text/figure
Attention deployment during memorizing and executing complex instructions.
We investigated the mental rehearsal of complex action instructions by recording spontaneous eye movements of healthy adults as they looked at objects on a monitor. Participants heard consecutive instructions, each of the form "move [object] to [location]". Instructions were only to be executed after a go signal, by manipulating all objects successively with a mouse. Participants re-inspected previously mentioned objects already while listening to further instructions. This rehearsal behavior broke down after 4 instructions, coincident with participants' instruction span, as determined from subsequent execution accuracy. These results suggest that spontaneous eye movements while listening to instructions predict their successful execution
Identifying Boosted Objects with N-subjettiness
We introduce a new jet shape -- N-subjettiness -- designed to identify
boosted hadronically-decaying objects like electroweak bosons and top quarks.
Combined with a jet invariant mass cut, N-subjettiness is an effective
discriminating variable for tagging boosted objects and rejecting the
background of QCD jets with large invariant mass. In efficiency studies of
boosted W bosons and top quarks, we find tagging efficiencies of 30% are
achievable with fake rates of 1%. We also consider the discovery potential for
new heavy resonances that decay to pairs of boosted objects, and find
significant improvements are possible using N-subjettiness. In this way,
N-subjettiness combines the advantages of jet shapes with the discriminating
power seen in previous jet substructure algorithms.Comment: 26 pages, 26 figures, 2 tables; v2: references added; v3: discussion
of results extende
The mass area of jets
We introduce a new characteristic of jets called mass area. It is defined so
as to measure the susceptibility of the jet's mass to contamination from soft
background. The mass area is a close relative of the recently introduced
catchment area of jets. We define it also in two variants: passive and active.
As a preparatory step, we generalise the results for passive and active areas
of two-particle jets to the case where the two constituent particles have
arbitrary transverse momenta. As a main part of our study, we use the mass area
to analyse a range of modern jet algorithms acting on simple one and
two-particle systems. We find a whole variety of behaviours of passive and
active mass areas depending on the algorithm, relative hardness of particles or
their separation. We also study mass areas of jets from Monte Carlo simulations
as well as give an example of how the concept of mass area can be used to
correct jets for contamination from pileup. Our results show that the
information provided by the mass area can be very useful in a range of
jet-based analyses.Comment: 36 pages, 12 figures; v2: improved quality of two plots, added entry
in acknowledgments, nicer form of formulae in appendix A; v3: added section
with MC study and pileup correction, version accepted by JHE
Genetic improvement of wheat for dry environments - a trait based approach
Item does not contain fulltext23 januari 201
The gravitino coupling to broken gauge theories applied to the MSSM
We consider gravitino couplings in theories with broken gauge symmetries. In
particular, we compute the single gravitino production cross section in W+ W-
fusion processes. Despite recent claims to the contrary, we show that this
process is always subdominant to gluon fusion processes in the high energy
limit. The full calculation is performed numerically; however, we give analytic
expressions for the cross section in the supersymmetric and electroweak limits.
We also confirm these results with the use of the effective theory of goldstino
interactions.Comment: 26 pages, 4 figure
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