1,931 research outputs found

    Goal-driven attentional capture by appetitive and aversive smoking-related cues in nicotine dependent smokers

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    BACKGROUND: Conventionally, involuntary attentional capture by tobacco cues in smokers are seen as an implicit bias, operating independently of current search goals. Prominent attention research, however, has suggested that search goals can induce an involuntary attentional capture. In the current investigation, we tested whether appetitive and aversive smoking images affected attention through such a mechanism and whether there were group differences based on nicotine dependence. METHODS: We instructed non-smokers (NS), occasional smokers (OS; low dependence), and nicotine-dependent smokers (NDS; moderate-high dependence), to hold search goals for either an aversive or appetitive smoking category, or a category of non-smoking images. These images were presented in a stream of briefly appearing filler images, while task-irrelevant distractors were presented outside the stream. Distractors could be aversive or appetitive smoking images or a category of non-smoking images. Therefore, in some conditions, the distractors matched the current category being searched for, while in others it was incongruent. RESULTS: Task-irrelevant smoking distractors reduced target detection, compared to the non-smoking distractors, only when they were congruent with the specific category being searched for. There was no effect of either aversive or appetitive smoking distractors on performance when participants were searching for the non-smoking targets. Distractor interference did not differ between smokers and non-smokers. CONCLUSIONS: The results support a goal-driven mechanism underpinning involuntary attentional capture by smoking cues. These findings can be used to inform models of addiction and attention, and the display of health warnings. KEYWORDS

    Testing a goal-driven account of involuntary attentional capture by threat

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    Attention has long been characterised within prominent models as reflecting a competition between goal-driven and stimulus-driven processes. It remains unclear, however, how involuntary attentional capture by affective stimuli, such as threat-laden content, fits into such models. While such effects were traditionally held to reflect stimulus-driven processes, recent research has increasingly implicated a critical role of goal-driven processes. Here we test an alternative goal-driven account of involuntary attentional capture by threat, using an experimental manipulation of goal-driven attention. To this end we combined the classic ‘contingent capture’ and ‘emotion-induced blink’ (EIB) paradigms in an RSVP task with both positive or threatening target search goals. Across six experiments, positive and threat distractors were presented in peripheral, parafoveal, and central locations. Across all distractor locations, we found that involuntary attentional capture by irrelevant threatening distractors could be induced via the adoption of a search goal for a threatening category; adopting a goal for a positive category conversely led to capture only by positive stimuli. Our findings provide direct experimental evidence for a causal role of voluntary goals in involuntary capture by irrelevant threat stimuli, and hence demonstrate the plausibility of a top-down account of this phenomenon. We discuss the implications of these findings in relation to current cognitive models of attention and clinical disorders

    An 11.6 Micron Keck Search For Exozodiacal Dust

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    We have begun an observational program to search nearby stars for dust disks that are analogous to the disk of zodiacal dust that fills the interior of our solar system. We imaged six nearby main-sequence stars with the Keck telescope at 11.6 microns, correcting for atmosphere-induced wavefront aberrations and deconvolving the point spread function via classical speckle analysis. We compare our data to a simple model of the zodiacal dust in our own system based on COBE/DIRBE observations and place upper limits on the density of exozodiacal dust in these systems.Comment: 10 pages, figure1, figure2, figure3, and figures 4a-

    A First Principles Theory of Nuclear Magnetic Resonance J-Coupling in solid-state systems

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    A method to calculate NMR J-coupling constants from first principles in extended systems is presented. It is based on density functional theory and is formulated within a planewave-pseudopotential framework. The all-electron properties are recovered using the projector augmented wave approach. The method is validated by comparison with existing quantum chemical calculations of solution-state systems and with experimental data. The approach has been applied to verify measured J-coupling in a silicophosphate structure, Si5O(PO4)6Comment: 9 page

    The quick and the dead: when reaction beats intention

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    Everyday behaviour involves a trade-off between planned actions and reaction to environmental events.Evidence from neurophysiology, neurology and functional brain imaging suggests different neural bases for the control of different movement types. Here we develop a behavioural paradigm to test movement dynamics for intentional versus reaction movements and provide evidence for a ‘reactive advantage’ in movement execution, whereby the same action is executed faster in reaction to an opponent. We placed pairs of participants in competition with each other to make a series of button presses. Within subject analysis of movement times revealed a 10 per cent benefit for reactive actions. This was maintained when opponents performed dissimilar actions, and when participants competed against a computer, suggesting that the effect is not related to facilitation produced by action observation. Rather, faster ballistic movements may be a general property of reactive motor control, potentially providing a useful means of promoting survival

    Not looking for any trouble? Purely affective attentional settings do not induce goal-driven attentional capture

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    It is well established that directing goal-driven attention to a particular stimulus property (e.g. red), or a conceptual category (e.g. toys) can induce powerful involuntary capture by goal-matching stimuli. Here we tested whether broad affective search goals (e.g. for anything threat-related) could similarly induce a generalised capture to an entire matching affective category. Across four experiments, participants were instructed to search for threat-related images in a Rapid Serial Visual Presentation (RSVP) stream, while ignoring threat-related distractors presented in task-irrelevant locations. Across these experiments we found no evidence of goal-driven attentional capture by threat distractors when participants adopted a general ‘threat detection’ goal encompassing multiple sub-categories of threat (Experiments 1a, 1b). This was true even when there was partial overlap between the threat distractors and the search goal (i.e. subset of the targets matched the distractor; Experiment 2). However, when participants adopted a more specific goal for a single sub-category of threat (e.g. fearful faces), robust goal-driven capture occurred by distractors matching this sub-category (Experiment 3). These findings suggest that while affective criteria can be used in the guidance of attention, attentional settings based on affective properties alone may not induce goal-driven attentional capture. We discuss implications for recent goal-driven accounts of affective attentional biases

    Air-Broadening of H2O as a Function of Temperature: 696 - 2163 cm(exp -1)

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    The temperature dependence of air-broadened halfwidths are reported for some 500 transitions in the (000)-(000) and (010)-(000) bands of H2(16)O using gas sample temperatures ranging from 241 to 388 K. These observations were obtained from infrared laboratory spectra recorded at 0.006 to 0.011 cm(exp-1) resolution with the McMath-Pierce Fourier transform spectrometer located at Kitt Peak. The experimental values of the temperature dependence exponents, eta, were grouped into eight subsets and fitted to empirical functions in a semi-global procedure. Overall, the values of eta were found to decrease with increasing rotational quantum number J. The number of measurements (over 2200) and transitions (586) involved exceeds by a large margin that of any other comparable reported study

    The estimated burden of fungal disease in South Africa

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    Publication fees were paid via funding from a grant from Fonds.Peer reviewedPublisher PD

    Angular Diameters of the G Subdwarf μ\mu Cassiopeiae A and the K Dwarfs σ\sigma Draconis and HR 511 from Interferometric Measurements with the CHARA Array

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    Using the longest baselines of the CHARA Array, we have measured the angular diameter of the G5 V subdwarf μ\mu Cas A, the first such determination for a halo population star. We compare this result to new diameters for the higher metallicity K0 V stars, σ\sigma Dra and HR 511, and find that the metal-poor star, μ\mu Cas A, has an effective temperature (Teff=5297±32T_{\rm eff}=5297\pm32 K), radius (R=0.791±0.008RR=0.791\pm0.008 R_{\rm \odot}), and absolute luminosity (L=0.442±0.014LL=0.442\pm0.014 L_{\rm \odot}) comparable to the other two stars with later spectral types. We show that stellar models show a discrepancy in the predicted temperature and radius for μ\mu Cas A, and we discuss these results and how they provide a key to understanding the fundamental relationships for stars with low metallicity.Comment: Accepted for publication in The Astrophysical Journa

    Recognition without identification, erroneous familiarity, and déjà vu

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    Déjà vu is characterized by the recognition of a situation concurrent with the awareness that this recognition is inappropriate. Although forms of déjà vu resolve in favor of the inappropriate recognition and therefore have behavioral consequences, typical déjà vu experiences resolve in favor of the awareness that the sensation of recognition is inappropriate. The resultant lack of behavioral modification associated with typical déjà vu means that clinicians and experimenters rely heavily on self-report when observing the experience. In this review, we focus on recent déjà vu research. We consider issues facing neuropsychological, neuroscientific, and cognitive experimental frameworks attempting to explore and experimentally generate the experience. In doing this, we suggest the need for more experimentation and amore cautious interpretation of research findings, particularly as many techniques being used to explore déjà vu are in the early stages of development.PostprintPeer reviewe
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