Insights from the application of computational neuroimaging to social neuroscience

A recent approach in social neuroscience has been the application of formal computational models for a particular social-cognitive process to neuroimaging data. Here we review preliminary findings from this nascent subfield, focusing on observational learning and strategic interactions. We present evidence consistent with the existence of three distinct learning systems that may contribute to social cognition: an observational-reward-learning system involved in updating expectations of future reward based on observing rewards obtained by others, an action-observational learning system involved in learning about the action tendencies of others, and a third system engaged when it is necessary to learn about the hidden mental-states or traits of another. These three systems appear to map onto distinct neuroanatomical substrates, and depend on unique computational signals

A versatile, refrigerant- and cryogen-free cryofocusing-thermodesorption unit for preconcentration of traces gases in air

We present a compact and versatile cryofocusing– thermodesorption unit, which we developed for quantitative analysis of halogenated trace gases in ambient air. Possible applications include aircraft-based in situ measurements, in situ monitoring and laboratory operation for the analysis of flask samples. Analytes are trapped on adsorptive material cooled by a Stirling cooler to low temperatures (e.g. -80°C) and subsequently desorbed by rapid heating of the adsorptive material (e.g. 200°C). The set-up involves neither the exchange of adsorption tubes nor any further condensation or refocusing steps. No moving parts are used that would require vacuum insulation. This allows for a simple and robust design. Reliable operation is ensured by the Stirling cooler, which neither contains a liquid refrigerant nor requires refilling a cryogen. At the same time, it allows for significantly lower adsorption temperatures compared to commonly used Peltier elements. We use gas chromatography – mass spectrometry (GC–MS) for separation and detection of the preconcentrated analytes after splitless injection. A substance boiling point range of approximately -80 to +150°C and a substance mixing ratio range of less than 1 ppt (pmol mol−1)to more than 500 ppt in preconcentrated sample volumes of 0.1 to 10 L of ambient air is covered, depending on the application and its analytical demands. We present the instrumental design of the preconcentration unit and demonstrate capabilities and performance through the examination of analyte breakthrough during adsorption, repeatability of desorption and analyte residues in blank tests. Examples of application are taken from the analysis of flask samples collected at Mace Head Atmospheric Research Station in Ireland using our laboratory GC–MS instruments and by data obtained during a research flight with our in situ aircraft instrument GhOSTMS (Gas chromatograph for the Observation of Tracers – coupled with a Mass Spectrometer)

Reappraisal of Incentives Ameliorates Choking Under Pressure and Is Correlated with Changes in the Neural Representations of Incentives

It has been observed that the pressure of performing for high stakes can, paradoxically, lead to uncharacteristically poor performance. Here we investigate a novel approach to attenuating such ‘choking under pressure’ by instructing participants performing a demanding motor task that rewards successful performance with a monetary gain, to reappraise this incentive as a monetary loss for unsuccessful performance. We show that when participants applied this simple strategy, choking was significantly reduced. This strategy also influenced participants’ neural and physiological activity. When participants reappraised the incentive as a potential monetary loss, the BOLD representation of the magnitude of the incentive in ventral striatum was attenuated. In addition, individual differences in the degree of attenuation of the neural response to incentive predicted the effectiveness of the reappraisal strategy in reducing choking. Furthermore, participants’ skin conductance changed in proportion to the magnitude of the incentive being played for, and was exaggerated on high incentive trials on which participants failed. Reappraisal of the incentive abolished this exaggerated skin conductance response. This represents the first experimental association of sympathetic arousal with choking. Taken together, these results suggest that reappraisal of the incentive is indeed a promising intervention for attenuating choking under pressure

Influence of appendicular skeletal muscle mass on resting metabolic equivalents in patients with cardiovascular disease: Implications for exercise training and prescription

The metabolic equivalent (MET) is a widely used physiological concept for quantifying levels of habitual physical activity and cardiorespiratory fitness (CRF). The MET conveys the oxygen consumption requirements of physical activities as multiples of the resting or basal metabolic rate (RMR). It may also be used to prescribe workloads for exercise training in patient groups, including those attending cardiac rehabilitation. One MET is considered to be equivalent to the oxygen consumed per kilogram of body mass at rest (while sitting) and, due to practical issues with direct metabolic cart measurements, it is conventionally approximated as 3.5 ml/kg–1/min–1. This expression of resting energy expenditure has been incorporated within physical activity position statements and guidelines. However, a number of factors – including age, sex, body mass (fat-free mass), cardiometabolic health and CRF – influence the RMR, which might limit the broad applicability of the conventional 1 MET at a population level. Widely prescribed cardiac drugs (i.e. beta blockers) have also been cited to influence the RMR, with some inconsistent findings in men. We aimed to evaluate the potential limitations of using the estimated MET in a cohort of patients with coronary heart disease (CHD), in whom we recently reported a positive association between skeletal muscle mass and peak oxygen uptake (O2peak). We hypothesized that patients with a lower skeletal muscle mass would also have a lower RMR, determined by resting respiratory gas analysis, and this would affect the accuracy of the aerobic exercise prescription based on METs

Anterior Insula Activity Reflects the Effects of Intentionality on the Anticipation of Aversive Stimulation

If someone causes you harm, your affective reaction to that person might be profoundly influenced by your inferences about the intentionality of their actions. In the present study, we aimed to understand how affective responses to a biologically salient aversive outcome administered by others are modulated by the extent to which a given individual is judged to have deliberately or inadvertently delivered the outcome. Using fMRI, we examined how neural responses to anticipation and receipt of an aversive stimulus are modulated by this fundamental social judgment. We found that affective evaluations about an individual whose actions led to either noxious or neutral consequences for the subject did indeed depend on the perceived intentions of that individual. At the neural level, activity in the anterior insula correlated with the interaction between perceived intentionality and anticipated outcome valence, suggesting that this region reflects the influence of mental state attribution on aversive expectations

A versatile, refrigerant- and cryogen-free cryofocusing-thermodesorption unit for preconcentration of traces gases in air

We present a compact and versatile cryofocusing–thermodesorption unit, which we developed for quantitative analysis of halogenated trace gases in ambient air. Possible applications include aircraft-based in situ measurements, in situ monitoring and laboratory operation for the analysis of flask samples. Analytes are trapped on adsorptive material cooled by a Stirling cooler to low temperatures (e.g. −80 °C) and subsequently desorbed by rapid heating of the adsorptive material (e.g. +200 °C). The set-up involves neither the exchange of adsorption tubes nor any further condensation or refocusing steps. No moving parts are used that would require vacuum insulation. This allows for a simple and robust design. Reliable operation is ensured by the Stirling cooler, which neither contains a liquid refrigerant nor requires refilling a cryogen. At the same time, it allows for significantly lower adsorption temperatures compared to commonly used Peltier elements. We use gas chromatography – mass spectrometry (GC–MS) for separation and detection of the preconcentrated analytes after splitless injection. A substance boiling point range of approximately −80 to +150 °C and a substance mixing ratio range of less than 1 ppt (pmol mol⁻¹) to more than 500 ppt in preconcentrated sample volumes of 0.1 to 10 L of ambient air is covered, depending on the application and its analytical demands. We present the instrumental design of the preconcentration unit and demonstrate capabilities and performance through the examination of analyte breakthrough during adsorption, repeatability of desorption and analyte residues in blank tests. Examples of application are taken from the analysis of flask samples collected at Mace Head Atmospheric Research Station in Ireland using our laboratory GC–MS instruments and by data obtained during a research flight with our in situ aircraft instrument GhOST-MS (Gas chromatograph for the Observation of Tracers – coupled with a Mass Spectrometer)

Dorsomedial Prefrontal Cortex Mediates Rapid Evaluations Predicting the Outcome of Romantic Interactions

Humans frequently make real-world decisions based on rapid evaluations of minimal information; for example, should we talk to an attractive stranger at a party? Little is known, however, about how the brain makes rapid evaluations with real and immediate social consequences. To address this question, we scanned participants with functional magnetic resonance imaging (fMRI) while they viewed photos of individuals that they subsequently met at real-life “speed-dating” events. Neural activity in two areas of dorsomedial prefrontal cortex (DMPFC), paracingulate cortex, and rostromedial prefrontal cortex (RMPFC) was predictive of whether each individual would be ultimately pursued for a romantic relationship or rejected. Activity in these areas was attributable to two distinct components of romantic evaluation: either consensus judgments about physical beauty (paracingulate cortex) or individualized preferences based on a partner's perceived personality (RMPFC). These data identify novel computational roles for these regions of the DMPFC in even very rapid social evaluations. Even a first glance, then, can accurately predict romantic desire, but that glance involves a mix of physical and psychological judgments that depend on specific regions of DMPFC

Re-Evaluation of the UK’s HFC-134a Emissions Inventory Based on Atmospheric Observations

Independent verification of national greenhouse gas inventories is a vital measure for cross-checking the accuracy of emissions data submitted to the United Nations Framework Convention on Climate Change (UNFCCC). We infer annual UK emissions of HFC-134a from 1995 to 2012 using atmospheric observations and an inverse modeling technique, and compare with the UK’s annual UNFCCC submission. By 2010, the inventory is almost twice as large as our estimates, with an “emissions gap” equating to 3.90 (3.20–4.30) Tg CO₂e. We evaluate the RAC (Refrigeration and Air-Conditioning) model, a bottom up model used to quantify UK emissions from refrigeration and air-conditioning sectors. Within mobile air-conditioning (MAC), the largest RAC sector and most significant UK source (59%), we find a number of assumptions that may be considered oversimplistic and conservative; most notably the unit refill rate. Finally, a Bayesian approach is used to estimate probable inventory inputs required for minimization of the emissions discrepancy. Our top-down estimates provide only a weak constraint on inventory model parameters and consequently, we are unable to suggest discrete values. However, a significant revision of the MAC servicing rate, coupled with a reassessment of non-RAC aerosol emissions, are required if the discrepancy between methods is to be reduced

The effect of protein and essential amino acid supplementation on muscle strength and performance in patients with chronic heart failure – A systematic review

Purpose Critically low skeletal muscle mass and strength, observed in 20% of people with chronic heart failure (CHF), reduces functional capacity, quality of life (QoL) and survival. Protein and essential amino acid (EAA) supplementation could be a viable treatment strategy to prevent declines in muscle strength and performance, and subsequently improve QoL and survival. This systematic review (PROSPERO: CRD42018103649) aimed to assess the effect of dietary protein and/or EAA supplementation on muscle strength and performance in people with CHF. Methods Searches of PubMed, MEDLINE and Embase identified studies that reported changes in strength or muscle performance following protein and/or EAA supplementation in patients with CHF. Following PRISMA guidelines and using predefined inclusion/exclusion criteria relating to participants, intervention, control, outcome and study design, two reviewers independently screened titles, abstracts and full manuscripts for eligibility. Risk of bias was assessed using Cochrane Risk of Bias Tool (RCTs) or Mixed Methods Appraisal Tool (cohort studies). Data were extracted for analysis using predefined criteria. Results Five randomised controlled trials (RCT) and one cohort study met our inclusion criteria. All RCTs had a high risk of bias. The methodological quality of the cohort study was moderate. Heterogeneity of extracted data prevented meta-analyses, qualitative synthesis was therefore performed. Data from 167 patients with CHF suggest that protein and/or EAA supplementation does not improve strength, but may increase six-minute walk test distance, muscle mass and QoL. Conclusions The limited quality of the studies makes firm conclusions difficult, however protein and/or EAA supplementation may improve important outcome measures related to sarcopenia. High-quality randomised controlled studies are needed