343 research outputs found
A habituation account of change detection in same/different judgments
We investigated the basis of change detection in a short-term priming task. In two experiments, participants were asked to indicate whether or not a target word was the same as a previously presented cue. Data from an experiment measuring magnetoencephalography failed to find different patterns for âsameâ and âdifferentâ responses, consistent with the claim that both arise from a common neural source, with response magnitude defining the difference between immediate novelty versus familiarity. In a behavioral experiment, we tested and confirmed the predictions of a habituation account of these judgments by comparing conditions in which the target, the cue, or neither was primed by its presentation in the previous trial. As predicted, cue-primed trials had faster response times, and target-primed trials had slower response times relative to the neither-primed baseline. These results were obtained irrespective of response repetition and stimulusâresponse contingencies. The behavioral and brain activity data support the view that detection of change drives performance in these tasks and that the underlying mechanism is neuronal habituation
The Relation Between the Surface Brightness and the Diameter for Galactic Supernova Remnants
In this work, we have constructed a relation between the surface brightness
() and diameter (D) of Galactic C- and S-type supernova remnants
(SNRs). In order to calibrate the -D dependence, we have carefully
examined some intrinsic (e.g. explosion energy) and extrinsic (e.g. density of
the ambient medium) properties of the remnants and, taking into account also
the distance values given in the literature, we have adopted distances for some
of the SNRs which have relatively more reliable distance values. These
calibrator SNRs are all C- and S-type SNRs, i.e. F-type SNRs (and S-type SNR
Cas A which has an exceptionally high surface brightness) are excluded. The
Sigma-D relation has 2 slopes with a turning point at D=36.5 pc: (at 1
GHz)=8.4 D
WmHzster (for
WmHzster and D36.5 pc) and (at 1
GHz)=2.7 10 D
WmHzster (for
WmHzster and D36.5 pc). We discussed the theoretical
basis for the -D dependence and particularly the reasons for the change
in slope of the relation were stated. Added to this, we have shown the
dependence between the radio luminosity and the diameter which seems to have a
slope close to zero up to about D=36.5 pc. We have also adopted distance and
diameter values for all of the observed Galactic SNRs by examining all the
available distance values presented in the literature together with the
distances found from our -D relation.Comment: 45 pages, 2 figures, accepted for publication in Astronomical and
Astrophysical Transaction
The Local Bubble, Local Fluff, and Heliosphere
The properties of the Local Bubble, Local Fluff complex of nearby
interstellar clouds, and the heliosphere are mutually constrained by data and
theory. Observations and models of the diffuse radiation field, interstellar
ionization, pick-up ion and anomalous cosmic-ray populations, and interstellar
dust link the physics of these regions. The differences between the
one-asymmetric-superbubble and two-superbubble views of the Local Bubble are
discussed.Comment: 10 pages, 2 figure
Recall termination in free recall
Although much is known about the dynamics of memory search in the free recall task, relatively little is known about the factors related to recall termination. Reanalyzing individual trial data from 14 prior studies (1,079 participants in 28,015 trials) and defining termination as occurring when a final response is followed by a long nonresponse interval, we observed that termination probability increased throughout the recall period and that retrieval was more likely to terminate following an error than following a correct response. Among errors, termination probability was higher following prior-list intrusions and repetitions than following extralist intrusions. To verify that this pattern of results can be seen in a single study, we report a new experiment in which 80 participants contributed recall data from a total of 9,122 trials. This experiment replicated the pattern observed in the aggregate analysis of the prior studies
Entanglements of faith: Discourses, practices of care and homeless people in an Italian City of Saints
This is the author accepted manuscript. The final version is available from SAGE via http://dx.doi.org/10.1177/0042098013514620This paper investigates how Catholic-inspired services for homeless people are delivered in Turin, Italy. The purpose is to critically interrogate particular faith-based organisationsâ moral discourses on homelessness, and to show how they are enacted through practices of care directed at the homeless subject. The paper contributes to the geographical literature on faith-based organisations addressing its shortcomings â namely the lack of critical and contextual focus on faith-based organisationsâ âlove for the poorâ. To address this point, the paper takes a vitalist perspective on the urban and introduces the notion of the âentanglements of faithâ, which allows an integrated and grounded perspective on faith-based organisationsâ interventions. The outcomes of the work suggest that these faith-based organisations propose standardised services that, producing particular assemblages and affective atmospheres, have deep emotional and relational effects on their recipients. Further lines of research are sketched in the conclusions
Massive Black Hole Binaries as LISA Precursors in the Roman High Latitude Time Domain Survey
With its capacity to observe faint active galactic nuclei
(AGN) out to redshift , Roman is poised to reveal a population of
black holes during an epoch of vigorous galaxy
assembly. By measuring the light curves of a subset of these AGN and looking
for periodicity, Roman can identify several hundred massive black hole binaries
(MBHBs) with 5-12 day orbital periods, which emit copious gravitational
radiation and will inevitably merge on timescales of years. During
the last few months of their merger, such binaries are observable with the
Laser Interferometer Space Antenna (LISA), a joint ESA/NASA gravitational wave
mission set to launch in the mid-2030s. Roman can thus find LISA precursors,
provide uniquely robust constraints on the LISA source population, help
identify the host galaxies of LISA mergers, and unlock the potential of
multi-messenger astrophysics with massive black hole binaries.Comment: White Paper for the Nancy Grace Roman Space Telescope's Core
Community Surveys (https://roman.gsfc.nasa.gov/science/ccs_white_papers.html
Delayed reconfiguration of a non-emotional task set through reactivation of an emotional task set in task switching: an ageing study
In our everyday life, we frequently switch between different tasks, a faculty that changes with age. However, it is still not understood how emotion impacts on age-related changes in task switching. Using faces with emotional and neutral expressions, Experiment 1 investigated younger (nâ=â29; 18â38 years old) and older adultsâ (nâ=â32; 61â80 years old) ability to switch between an emotional and a non-emotional task (i.e. responding to the face's expression vs. age). In Experiment 2, younger and older adults also viewed emotional and neutral faces, but switched between two non-emotional tasks (i.e. responding to the face's age vs. gender). Data from Experiment 1 demonstrated that switching from an emotional to a non-emotional task was slower when the expression of the new face was emotional rather than neutral. This impairment was observed in both age groups. In contrast, Experiment 2 revealed that neither younger nor older adults were affected by block-wise irrelevant emotion when switching between two non-emotional tasks. Overall, the findings suggest that task-irrelevant emotion can impair task switching through reactivation of the competing emotional task set. They also suggest that this effect and the ability to shield task-switching performance from block-wise irrelevant emotion are preserved in ageing
Event Horizon Telescope observations of the jet launching and collimation in Centaurus A
Very-long-baseline interferometry (VLBI) observations of active galactic nuclei at millimetre wavelengths have the power to reveal the launching and initial collimation region of extragalactic radio jets, down to 10â100 gravitational radii (rg ⥠GM/c2) scales in nearby sources1. Centaurus A is the closest radio-loud source to Earth2. It bridges the gap in mass and accretion rate between the supermassive black holes (SMBHs) in Messier 87 and our Galactic Centre. A large southern declination of â43° has, however, prevented VLBI imaging of Centaurus A below a wavelength of 1 cm thus far. Here we show the millimetre VLBI image of the source, which we obtained with the Event Horizon Telescope at 228 GHz. Compared with previous observations3, we image the jet of Centaurus A at a tenfold higher frequency and sixteen times sharper resolution and thereby probe sub-lightday structures. We reveal a highly collimated, asymmetrically edge-brightened jet as well as the fainter counterjet. We find that the source structure of Centaurus A resembles the jet in Messier 87 on ~500 rg scales remarkably well. Furthermore, we identify the location of Centaurus Aâs SMBH with respect to its resolved jet core at a wavelength of 1.3 mm and conclude that the sourceâs event horizon shadow4 should be visible at terahertz frequencies. This location further supports the universal scale invariance of black holes over a wide range of masses5,6
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