Reevaluating evaluative conditioning: A nonassociative explanation of conditioning effects in the visual evaluative conditioning paradigm

In 2 studies, the authors investigated whether evaluative conditioning (EC) is an associative phenomenon. Experiment 1 compared a standard EC paradigm with nonpaired and no-treatment control conditions. EC effects were obtained only when the conditioned stimulus (CS) and unconditioned stimulus (UCS) were rated as perceptually similar. However, similar EC effects were obtained in both control groups. An earlier failure to obtain EC effects was reanalyzed in Experiment 2. Conditioning-like effects were found when comparing a CS with the most perceptually similar UCSs used in the procedure but not when analyzing a CS rating with respect to the UCS with which it was paired during conditioning. The implications are that EC effects found in many studies are not due to associative learning and that the special characteristics of EC (conditioning without awareness and resistance to extinction) are probably nonassociative artifacts of the EC paradigm

The effect of facial feedback on the evaluation of statements describing everyday situations and the role of awareness

According to theories of embodiment enacting a smile or a frown can positively or negatively influence one’s evaluations, even without awareness of one’s facial activity. While some previous studies found evidence for facial feedback effects, recent replication attempts could not confirm these findings. Are our decisions throughout the day amenable to the state of our facial muscles? We tested the effect of smiling and frowning on the evaluation of emotional sentences describing everyday situations. While most previous studies based their assessment of awareness on verbal debriefing interviews without explicitly defined criteria, we employed a written debriefing questionnaire in order to avoid potential bias when identifying participants’ awareness. Our results indicate that smiling/frowning increased/decreased sentence ratings only for participants aware of their expressions. This emphasizes the importance of more rigorous awareness tests in facial feedback studies. Our results support the view that facial feedback cannot necessarily influence us without conscious mediation

Particle abundance in a thermal plasma: quantum kinetics vs. Boltzmann equation

We study the abundance of a particle species in a thermalized plasma by introducing a quantum kinetic description based on the non-equilibrium effective action. A stochastic interpretation of quantum kinetics in terms of a Langevin equation emerges naturally. We consider a particle species that is stable in the vacuum and interacts with \emph{heavier} particles that constitute a thermal bath in equilibrium and define of a fully renormalized single particle distribution function. The distribution function thermalizes on a time scale determined by the \emph{quasiparticle} relaxation rate. The equilibrium distribution function depends on the full spectral density and features off-shell contributions to the particle abundance. A model of a bosonic field $\Phi$ in interaction with two \emph{heavier} bosonic fields is studied. We find substantial departures from the Bose-Einstein result both in the high temperature and the low temperature but high momentum region. In the latter the abundance is exponentially suppressed but larger than the Bose-Einstein result. We obtain the Boltzmann equation in renormalized perturbation theory and highlight the origin of the differences. We argue that the corrections to the abundance of cold dark matter candidates are observationally negligible and that recombination erases any possible spectral distortions of the CMB. However we expect that the enhancement at high temperature may be important for baryogenesis.Comment: 39 pages, 11 figures. Clarifying remarks. To appear in Physical Review

The effect of worrying on intolerance of uncertainty and positive and negative beliefs about worry

Background and Objectives: The effect of a worry manipulation on the clinical constructs intolerance of uncertainty (IU), negative beliefs about the consequences of worry (NCOW), positive beliefs about the consequences of worry (PCOW), in addition to the emotions anxiety and sadness, was examined. Methods: A non-clinical sample was split into two groups, a worry group (n = 29), who were asked to generate 20 potential worries about a hypothetical scenario, and a control group (n = 28), who were asked to generate 2 potential worries about the same scenario. Subsequently, participants were asked to complete measures of IU, NCOW, PCOW, sadness and anxiety. Results: The worry group scored significantly higher than the control group on measures of IU, NCOW and PCOW but not on measures of sadness and anxiety. Limitations: Possible limitations of the current study include the use of a student sample and the use of a hypothetical worry scenario. Conclusions: The results suggest that engaging in worry can increase scores on measures of the beliefs and thought patterns often used to causally explain worry. The results are in line with recent research showing bidirectionality between anxiety related symptoms and their associated clinical constructs, and are consistent with an approach which sees anxiety symptoms as part of an evolved integrated threat management system that alerts the individual to threats to goals or challenges, and coordinates cognitive, behavioral, and affective reactions to enable effective responding to these threats and challenges

Recovering high-quality FODs from a reduced number of diffusion-weighted images using a model-driven deep learning architecture

Fibre orientation distribution (FOD) reconstruction using deep learning has the potential to produce accurate FODs from a reduced number of diffusion-weighted images (DWIs), decreasing total imaging time. Diffusion acquisition invariant representations of the DWI signals are typically used as input to these methods to ensure that they can be applied flexibly to data with different b-vectors and b-values; however, this means the network cannot condition its output directly on the DWI signal. In this work, we propose a spherical deconvolution network, a model-driven deep learning FOD reconstruction architecture, that ensures intermediate and output FODs produced by the network are consistent with the input DWI signals. Furthermore, we implement a fixel classification penalty within our loss function, encouraging the network to produce FODs that can subsequently be segmented into the correct number of fixels and improve downstream fixel-based analysis. Our results show that the model-based deep learning architecture achieves competitive performance compared to a state-of-the-art FOD super-resolution network, FOD-Net. Moreover, we show that the fixel classification penalty can be tuned to offer improved performance with respect to metrics that rely on accurately segmented of FODs. Our code is publicly available at https://github.com/Jbartlett6/SDNet .Comment: 10 pages, 7 figures, This work has been submitted to the IEEE for possible publication. Copyright may be transferred without notice, after which this version may no longer be accessibl

Podoconiosis in East and West Gojam Zones, Northern Ethiopia

Background: Podoconiosis is a neglected tropical disease (NTD) that is prevalent in red clay soil-covered highlands of tropical Africa, Central and South America, and northern India. It is estimated that up to one million cases exist in Ethiopia. This study aimed to estimate the prevalence of podoconiosis in East and West Gojam Zones of Amhara Region in northern Ethiopia. Methodology/Principal Findings: A cross-sectional household survey was conducted in Debre Eliyas and Dembecha woredas (districts) in East and West Gojam Zones, respectively. The survey covered all 17,553 households in 20 kebeles (administrative subunits) randomly selected from the two woredas. A detailed structured interview was conducted on 1,704 cases of podoconiosis identified in the survey. Results: The prevalence of podoconiosis in the population aged 15 years and above was found to be 3.3% (95% CI, 3.2% to 3.6%). 87% of cases were in the economically active age group (15–64 years). On average, patients sought treatment five years after the start of the leg swelling. Most subjects had second (42.7%) or third (36.1%) clinical stage disease, 97.9% had mossy lesions, and 53% had open wounds. On average, patients had five episodes of acute adenolymphangitis (ALA) per year and spent a total of 90 days per year with ALA. The median age of first use of shoes and socks were 22 and 23 years, respectively. More men than women owned more than one pair of shoes (61.1% vs. 50.5%; x2 = 11.6 p = 0.001). At the time of interview, 23.6% of the respondents were barefoot, of whom about two-thirds were women. Conclusions: This study showed high prevalence of podoconiosis and associated morbidities such as ALA, mossy lesions and open wounds in northern Ethiopia. Predominance of cases at early clinical stage of podoconiosis indicates the potential for reversing the swelling and calls for disease prevention interventions