309 research outputs found
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
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
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/kgâ1/minâ1. This expression of resting energy expenditure has been incorporated within physical activity position statements and guidelines. However, a number of factors â including age, sex, body mass (fat-free mass), cardiometabolic health and CRF â 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
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 âspeed-datingâ 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
A versatile, refrigerant- and cryogen-free cryofocusing-thermodesorption unit for preconcentration of traces gases in air
We present a compact and versatile
cryofocusingâthermodesorption 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.
â80âŻÂ°C) and subsequently desorbed by rapid heating of the
adsorptive material (e.g. +200âŻÂ°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 â mass spectrometry (GCâMS) for separation and detection
of the preconcentrated analytes after splitless injection. A substance
boiling point range of approximately â80 to +150âŻÂ°C and a
substance mixing ratio range of less than 1âŻppt (pmolâŻmol<sup>â1</sup>) to more
than 500âŻppt in preconcentrated sample volumes of 0.1 to 10âŻL 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 GCâMS instruments and by
data obtained during a research flight with our in situ aircraft instrument
GhOST-MS (Gas chromatograph for the Observation of Tracers â coupled with a Mass
Spectrometer)
A versatile, refrigerant- and cryogen-free cryofocusing-thermodesorption unit for preconcentration of traces gases in air
We present a compact and versatile cryofocusingâ 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 â mass spectrometry (GCâMS) 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 molâ1)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 GCâMS instruments and by data obtained during a research flight with our in situ aircraft instrument GhOSTMS (Gas chromatograph for the Observation of Tracers â 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 âchoking under pressureâ 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 participantsâ 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, participantsâ 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
The Neural Representation of Unexpected Uncertainty during Value-Based Decision Making
Uncertainty is an inherent property of the environment
and a central feature of models of decision-making
and learning. Theoretical propositions suggest
that one form, unexpected uncertainty, may be
used to rapidly adapt to changes in the environment,
while being influenced by two other forms: risk and
estimation uncertainty. While previous studies have
reported neural representations of estimation uncertainty
and risk, relatively little is known about unexpected
uncertainty. Here, participants performed
a decision-making task while undergoing functional
magnetic resonance imaging (fMRI), which, in combination
with a Bayesian model-based analysis,
enabled us to separately examine each form of uncertainty
examined. We found representations of unexpected
uncertainty in multiple cortical areas, as
well as the noradrenergic brainstem nucleus locus
coeruleus. Other unique cortical regions were found
to encode risk, estimation uncertainty, and learning
rate. Collectively, these findings support theoretical
models in which several formally separable uncertainty
computations determine the speed of learning
Provision of dietary education in UK-based cardiac rehabilitation: a cross-sectional survey conducted in conjunction with the British Association for Cardiovascular Prevention and Rehabilitation.
Dietary education is a core component of cardiac rehabilitation (CR). It is unknown how or what dietary education is delivered across the United Kingdom (UK). We aimed to characterise practitioners who deliver dietary education in UK CR and determine the format and content of the education sessions. A 54-item survey was approved by the British Association for Cardiovascular Prevention and Rehabilitation (BACPR) committee and circulated between July and October 2021 via two emails to the BACPR mailing list and on social media. Practitioners providing dietary education within CR programmes were eligible to respond. Survey questions encompassed: practitioner job title and qualifications, resources, and the format, content and individual tailoring of diet education. Forty-nine different centres responded. Nurses (65.1%) and dietitians (55.3%) frequently provided dietary education. Practitioners had no nutrition-related qualifications in 46.9% of services. Most services used credible resources to support their education, and 24.5% used BACPR core competencies. CR programmes were mostly community-based (40.8%), lasting 8-weeks (range: 2-25) and included 2 (range: 1-7) diet sessions. Dietary history was assessed at the start (79.6%) and followed-up (83.7%) by most centres; barriers to completing assessment were insufficient time, staffing, or other priorities. Services mainly focused on the Mediterranean diet whilst topics such as malnutrition and protein intake were lower priority topics. Service improvement should focus on increasing qualifications of practitioners, standardisation of dietary assessment, and improvement in protein and malnutrition screening and assessment
Neural Mechanisms Underlying Human Consensus Decision-Making
Consensus building in a group is a hallmark of animal societies, yet little is known about its underlying computational and neural mechanisms. Here, we applied a computational framework to behavioral and fMRI data from human participants performing a consensus decision-making task with up to five other participants. We found that participants reached consensus decisions through integrating their own preferences with information about the majority group membersâ prior choices, as well as inferences about how much each option was stuck to by the other people. These distinct decision variables were separately encoded in distinct brain areasâthe ventromedial prefrontal cortex, posterior superior temporal sulcus/temporoparietal junction, and intraparietal sulcusâand were integrated in the dorsal anterior cingulate cortex. Our findings provide support for a theoretical account in which collective decisions are made through integrating multiple types of inference about oneself, others, and environments, processed in distinct brain modules
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