Is action understanding an automatic process? Both cognitive and perceptual processing are required for the identification of actions and intentions.

The ability to identify others' actions and intentions, "action understanding," is crucial for successful social interaction. Under direct accounts, action understanding takes place without the involvement of inferential processes, a claim that has yet to be tested using behavioural measures. Using a dual-task paradigm, the present study aimed to establish whether the identification of others' actions and intentions depends on automatic or inferential processing, by manipulating working memory load during performance of a task designed to target the identification of actions and intentions. Experiment 1 tested a novel action understanding task targeting action identification and intention identification. This task was then combined with two working memory manipulations (cognitive: Experiment 2; perceptual: Experiment 3) to determine whether action identification and intention identification are disrupted by concurrent cognitive or perceptual load. Both action identification and intention identification were impaired by concurrent cognitive and perceptual processing, indicating that action understanding requires additional perceptual and cognitive resources. These findings contradict a direct account of action understanding.

Mirror neuron brain regions contribute to identifying actions, but not intentions.

Previous studies have struggled to determine the relationship between mirror neuron brain regions and two distinct "action understanding" processes: identifying actions and identifying the intentions underlying those actions. This may be because the identification of intentions from others' actions requires an initial action identification process. Disruptive transcranial magnetic stimulation was administered to left inferior frontal gyrus (lIFG) during a novel cognitive task to determine which of these "action understanding" processes is subserved by mirror neuron brain regions. Participants identified either the actions performed by observed hand actions or the intentions underlying those actions. The extent to which intention identification was disrupted by lIFG (vs. control site) stimulation was dependent on the level of disruption to action identification. We subsequently performed functional magnetic resonance imaging during the same task. During action identification, responses were widespread within mirror neuron areas including lIFG and inferior parietal lobule. However, no independent responses were found in mirror neuron brain regions during intention identification. Instead, responses occurred in brain regions associated with two distinct mentalizing localizer tasks. This supports an account in which mirror neuron brain regions are involved in an initial action identification process, but the subsequent identification of intentions requires additional processing in mentalizing brain regions.

The future of orthopaedic surgical education: Where do we go now?

INTRODUCTION: COVID-19 will undoubtedly change the future landscape of medical and surgical education. The economic and environmental advantages of virtual learning are clear, while access to a wider range of resources and subject specialists makes the adoption of virtual learning within surgical education an attractive prospect. AIMS: This literature review aims to evaluate evidence on the effectiveness of virtual education in orthopaedics and how we might implement positive changes to educational practice in the future, as a result of lessons learned during the COVID-19 pandemic. METHODOLOGY: We performed a review of the literature reporting on efficacy of learning outcomes achieved as a result of virtual education within orthopaedic surgery. Electronic searches were performed using NICE healthcare databases from the date of inception to March 2021. Relevant studies were identified, data extracted, and qualitative synthesis performed. RESULTS: 14 manuscripts with a total of 1548 participants (orthopaedic trainees or medical students) were included for analysis. Nine studies (n = 1109) selected compared e-learning to conventional learning material (control group). All nine studies reported significantly higher outcome scores for e-learning participants compared to control participants (p < 0.001 to p < 0.05). The remaining studies compared blended e-learning approaches or evaluated pre/post intervention improvements in learning outcomes. All studies demonstrated a significant improvement in learning outcomes (p < 0.0001 to p < 0.01). The majority of studies (64%) used a blended approach. No studies were identified reporting efficacy of webinars or videoconferencing within orthopaedic education. CONCLUSION: A blended approach, combining virtual teaching, face-to-face instruction and distance learning tools, based on the evidence we have provided, would improve the quality of knowledge reception and retention, and learner satisfaction. However, in order to be successful, it is vital that these educational programmes are designed with the needs of the learner in mind, and an awareness of best practice for virtual teaching and learning.

Conceptualizing and testing action understanding.

The term 'action understanding' has been defined in several ways since it was first proposed to describe the psychological process subserved by mirror neurons. Here we outline and critique these definitions of 'action understanding' in order to evaluate the claim that mirror neurons perform such a process. We delineate three distinct definitions of 'action understanding', each involving a distinct psychological process. Action identification comprises using the specific configurations of body parts in observed actions to identify those actions, whereas goal identification and intention identification involve generalising across different observed actions to identify the immediate goal of, or the hidden mental state motivating, the actions. This paper discusses the benefits and drawbacks of using these definitions to describe the process purportedly performed by mirror neurons. We then examine each definition in relation to the mirror neuron literature. We conclude that although there is some evidence consistent with the suggestion that mirror neurons contribute to action identification, there is little evidence to support the claim that they contribute to goal or intention identification.

Adrenaline activation of the carotid body: Key to CO2 and pH homeostasis in hypoglycaemia and potential pathological implications in cardiovascular disease.

Ventilatory and neuroendocrine counter-regulatory responses during hypoglycaemia are essential in order to maintain glycolysis and prevent rises in PaCO2 leading to systemic acidosis. The mammalian carotid body has emerged as an important driver of hyperpnoea and glucoregulation in hypoglycaemia. However, the adequate stimulus for CB stimulation in hypoglycaemia has remained controversial for over a decade. The recent finding that adrenaline is a physiological activator of CB in hypoglycaemia raises the intriguing possibility that CB stimulation and hyperpnoea may be necessary to maintain pH in other adrenaline-related hypermetabolic states such as exercise. This review will therefore focus on 1) The important functional contribution of the CB in the counter-regulatory and ventilatory response to hypoglycaemia, 2) the proposed mechanisms that cause CB stimulation in hypoglycaemia including hormonal activation by adrenaline and direct low glucose sensing and 3) the possible pathological consequences of repetitive CB activation by adrenaline that could potentially be targeted to reduce CB-mediated cardiovascular disease.

A Network Analysis of the Links Between Chronic Pain Symptoms and Affective Disorder Symptoms.

BACKGROUND: A range of psychological constructs, including perceived pain, self-efficacy, and pain avoidance, have been proposed to account for the comorbidity of chronic pain and affective disorder symptoms. Despite the likely inter-relation among these constructs, few studies have explored these predictors simultaneously. As such, the relative contributions of these psychological influences remain an open question. PURPOSE: The present study uses a novel, network model approach to help to identify the key psychological contributors to the pain-affective disorder link. METHOD: A cross-sectional design was implemented. The sample comprised 169 individuals with chronic pain (Mage 49.82; range 22-80 years; 58% female) admitted to a metropolitan chronic pain clinic in Victoria, Australia. Participants completed self-report measures of anxiety, depressive, and pain symptoms, pain self-efficacy, fear avoidance beliefs, perceived control, and pain-related disability. RESULTS: Network analysis identified self-efficacy, fear avoidance, and perceived disability as key constructs in the relationship between pain and affective disorder symptoms, albeit in different ways. While self-efficacy appeared to have direct links to other constructs in the network model, fear avoidance and perceived disability seemed to function more as mediators, linking other constructs in the model. Perceived control and anxiety were found to be less influential in the model. CONCLUSIONS: Present findings identify self-efficacy, fear avoidance, and perceived disability as plausible candidate variables to target to disrupt the link between pain experience and affective disorder symptoms. However, further testing with longitudinal designs is needed to confirm this.

Sensorimotor training alters action understanding.

The discovery of 'mirror' neurons stimulated intense interest in the role of motor processes in social interaction. A popular assumption is that observation-related motor activation, exemplified by mirror neurons' matching properties, evolved to subserve the 'understanding' of others' actions. Alternatively, such motor activation may result from sensorimotor learning. Sensorimotor training alters observation-related motor activation, but studies demonstrating training-dependent changes in motor activation have not addressed the functional role of such activation. We therefore tested whether sensorimotor learning alters action understanding. Participants completed an action understanding task, judging the weight of boxes lifted by another person, before and after 'counter-mirror' sensorimotor training. During this training they lifted heavy boxes while observing light boxes being lifted, and vice-versa. Compared to a control group, this training significantly reduced participants' action understanding ability. Performance on a duration judgement task was unaffected by training. These data suggest the ability to understand others' actions results from sensorimotor learning.

Transcriptomic profiling of adaptive responses to ocean acidification.

Some populations of marine organisms appear to have inherent tolerance or the capacity for acclimation to stressful environmental conditions, including those associated with climate change. Sydney rock oysters from the B2 breeding line exhibit resilience to ocean acidification (OA) at the physiological level. To understand the molecular basis of this physiological resilience, we analysed the gill transcriptome of B2 oysters that had been exposed to near-future projected ocean pH over two consecutive generations. Our results suggest that the distinctive performance of B2 oysters in the face of OA is mediated by the selective expression of genes involved in multiple cellular processes. Subsequent high-throughput qPCR revealed that some of these transcriptional changes are exclusive to B2 oysters and so may be associated with their resilience to OA. The intracellular processes mediated by the differentially abundant genes primarily involve control of the cell cycle and maintenance of cellular homeostasis. These changes may enable B2 oysters to prevent apoptosis resulting from oxidative damage or to alleviate the effects of apoptosis through regulation of the cell cycle. Comparative analysis of the OA conditioning effects across sequential generations supported the contention that B2 and wild-type oysters have different trajectories of changing gene expression and responding to OA. Our findings reveal the broad set of molecular processes underlying transgenerational conditioning and potential resilience to OA in a marine calcifier. Identifying the mechanisms of stress resilience can uncover the intracellular basis for these organisms to survive and thrive in a rapidly changing ocean.

Contrasting impacts of ocean acidification and warming on the molecular responses of CO2-resilient oysters.

BACKGROUND: This study characterises the molecular processes altered by both elevated CO2 and increasing temperature in oysters. Differences in resilience of marine organisms against the environmental stressors associated with climate change will have significant implications for the sustainability of coastal ecosystems worldwide. Some evidence suggests that climate change resilience can differ between populations within a species. B2 oysters represent a unique genetic resource because of their capacity to better withstand the impacts of elevated CO2 at the physiological level, compared to non-selected oysters from the same species (Saccostrea glomerata). Here, we used proteomic and transcriptomic analysis of gill tissue to evaluate whether the differential response of B2 oysters to elevated CO2 also extends to increased temperature. RESULTS: Substantial and distinctive effects on protein concentrations and gene expression were evident among B2 oysters responding to elevated CO2 or elevated temperature. The combination of both stressors also altered oyster gill proteomes and gene expression. However, the impacts of elevated CO2 and temperature were not additive or synergistic, and may be antagonistic. CONCLUSIONS: The data suggest that the simultaneous exposure of CO2-resilient oysters to near-future projected ocean pH and temperature results in complex changes in molecular processes in order to prevent stress-induced cellular damage. The differential response of B2 oysters to the combined stressors also indicates that the addition of thermal stress may impair the resilience of these oysters to decreased pH. Overall, this study reveals the intracellular mechanisms that might enable marine calcifiers to endure the emergent, adverse seawater conditions resulting from climate change.

Rapid transcriptional acclimation following transgenerational exposure of oysters to ocean acidification.

Marine organisms need to adapt in order to cope with the adverse effects of ocean acidification and warming. Transgenerational exposure to CO2 stress has been shown to enhance resilience to ocean acidification in offspring from a number of species. However, the molecular basis underlying such adaptive responses is currently unknown. Here, we compared the transcriptional profiles of two genetically distinct oyster breeding lines following transgenerational exposure to elevated CO2 in order to explore the molecular basis of acclimation or adaptation to ocean acidification in these organisms. The expression of key target genes associated with antioxidant defence, metabolism and the cytoskeleton was assessed in oysters exposed to elevated CO2 over three consecutive generations. This set of target genes was chosen specifically to test whether altered responsiveness of intracellular stress mechanisms contributes to the differential acclimation of oyster populations to climate stressors. Transgenerational exposure to elevated CO2 resulted in changes to both basal and inducible expression of those key target genes (e.g. ecSOD, catalase and peroxiredoxin 6), particularly in oysters derived from the disease-resistant, fast-growing B2 line. Exposure to CO2 stress over consecutive generations produced opposite and less evident effects on transcription in a second population that was derived from wild-type (nonselected) oysters. The analysis of key target genes revealed that the acute responses of oysters to CO2 stress appear to be affected by population-specific genetic and/or phenotypic traits and by the CO2 conditions to which their parents had been exposed. This supports the contention that the capacity for heritable change in response to ocean acidification varies between oyster breeding lines and is mediated by parental conditioning.

Adrenaline release evokes hyperpnoea and an increase in ventilatory CO2 sensitivity during hypoglycaemia: a role for the carotid body.

KEY POINTS: Hypoglycaemia is counteracted by release of hormones and an increase in ventilation and CO2 sensitivity to restore blood glucose levels and prevent a fall in blood pH. The full counter-regulatory response and an appropriate increase in ventilation is dependent on carotid body stimulation. We show that the hypoglycaemia-induced increase in ventilation and CO2 sensitivity is abolished by preventing adrenaline release or blocking its receptors. Physiological levels of adrenaline mimicked the effect of hypoglycaemia on ventilation and CO2 sensitivity. These results suggest that adrenaline, rather than low glucose, is an adequate stimulus for the carotid body-mediated changes in ventilation and CO2 sensitivity during hypoglycaemia to prevent a serious acidosis in poorly controlled diabetes. ABSTRACT: Hypoglycaemia in vivo induces a counter-regulatory response that involves the release of hormones to restore blood glucose levels. Concomitantly, hypoglycaemia evokes a carotid body-mediated hyperpnoea that maintains arterial CO2 levels and prevents respiratory acidosis in the face of increased metabolism. It is unclear whether the carotid body is directly stimulated by low glucose or by a counter-regulatory hormone such as adrenaline. Minute ventilation was recorded during infusion of insulin-induced hypoglycaemia (8-17 mIU kg(-1)  min(-1) ) in Alfaxan-anaesthetised male Wistar rats. Hypoglycaemia significantly augmented minute ventilation (123 ± 4 to 143 ± 7 ml min(-1) ) and CO2 sensitivity (3.3 ± 0.3 to 4.4 ± 0.4 ml min(-1)  mmHg(-1) ). These effects were abolished by either ß-adrenoreceptor blockade with propranolol or adrenalectomy. In this hypermetabolic, hypoglycaemic state, propranolol stimulated a rise in P aC O2, suggestive of a ventilation-metabolism mismatch. Infusion of adrenaline (1 µg kg(-1)  min(-1) ) increased minute ventilation (145 ± 4 to 173 ± 5 ml min(-1) ) without altering P aC O2 or pH and enhanced ventilatory CO2 sensitivity (3.4 ± 0.4 to 5.1 ± 0.8 ml min(-1)  mmHg(-1) ). These effects were attenuated by either resection of the carotid sinus nerve or propranolol. Physiological concentrations of adrenaline increased the CO2 sensitivity of freshly dissociated carotid body type I cells in vitro. These findings suggest that adrenaline release can account for the ventilatory hyperpnoea observed during hypoglycaemia by an augmented carotid body and whole body ventilatory CO2 sensitivity.

Do Pain-related Beliefs Influence Adherence to Multidisciplinary Rehabilitation?: A Systematic Review.

OBJECTIVES: To understand how pain-related cognitions predict and influence treatment retention and adherence during and after a multidisciplinary rehabilitation program. METHODS: Electronic databases including Medline, CINAHL, PsycINFO, Academic Search Complete, and Scopus were used to search 3 combinations of key words: chronic pain, beliefs, and treatment adherence. RESULTS: The search strategy yielded 591 results, with an additional 12 studies identified through reference screening. Eighty-one full-text papers were assessed for eligibility and 10 papers met the inclusion and exclusion criteria for this review. The pain-related beliefs that have been measured in relation to treatment adherence include: pain-specific self-efficacy, perceived disability, catastrophizing, control beliefs, fear-avoidance beliefs, perceived benefits and barriers, and other less commonly measured beliefs. The most common pain-related belief investigated in relation to treatment adherence was pain-related self-efficacy. Findings for the pain-related beliefs investigated among the studies were mixed. Collectively, all of the aforementioned pain-related beliefs, excluding control beliefs, were found to influence treatment adherence behaviors. DISCUSSION: The findings suggest that treatment adherence is determined by a combination of pain-related beliefs either supporting or inhibiting chronic pain patients' ability to adhere to treatment recommendations over time. In the studies reviewed, self-efficacy appears to be the most commonly researched predictor of treatment adherence, its effects also influencing other pain-related beliefs. More refined and standardized methodologies, consistent descriptions of pain-related beliefs, and methods of measurement will improve our understanding of adherence behaviors.

Meta-analysis of studies using suppression subtractive hybridization and microarrays to investigate the effects of environmental stress on gene transcription in oysters.

Many microarray and suppression subtractive hybridization (SSH) studies have analyzed the effects of environmental stress on gene transcription in marine species. However, there have been no unifying analyses of these data to identify common stress response pathways. To address this shortfall, we conducted a meta-analysis of 14 studies that investigated the effects of different environmental stressors on gene expression in oysters. The stressors tested included chemical contamination, hypoxia and infection, as well as extremes of temperature, pH and turbidity. We found that the expression of over 400 genes in a range of oyster species changed significantly after exposure to environmental stress. A repeating pattern was evident in these transcriptional responses, regardless of the type of stress applied. Many of the genes that responded to environmental stress encoded proteins involved in translation and protein processing (including molecular chaperones), the mitochondrial electron transport chain, anti-oxidant activity and the cytoskeleton. In light of these findings, we put forward a consensus model of sub-cellular stress responses in oysters.

Dose-dependent effects of metals on gene expression in the sydney rock oyster, Saccostrea glomerata.

In the current study, we tested the effects of common environmental contaminants (the metals zinc and lead) on gene expression in Sydney rock oysters (Saccrostrea glomerata). Oysters were exposed to a range of metal concentrations under controlled laboratory conditions. The expression of 14 putative stress response genes was then measured using quantitative, real-time (q) PCR. The expression of all 14 genes was significantly affected (p < 0.05 vs. nonexposed controls) by at least one of the metals, and by at least one dose of metal. For 5 of the 14 target genes (actin, calmodulin, superoxide dismutase, topoisomerase I, and tubulin) the alteration of expression relative to controls was highest at intermediate (rather than high) doses of metals. Such responses may reflect adaptive (acclimation) reactions in gene expression at low to intermediate doses of contaminants, followed by a decline in expression resulting from exposure at higher doses. The data are discussed in terms of the intracellular pathways affected by metal contamination, and the relevance of such gene expression data to environmental biomonitoring.

How images may or may not represent flowers: picture-object correspondence in bumblebees (Bombus impatiens)?

Studies of bee cognition frequently use two-dimensional stimuli referred to as floral patterns, and yet how bees perceive pictorial representations is not known. An investigation of bumblebee (Bombus impatiens) picture-object correspondence was undertaken according to the theory of Fagot et al. (Picture perception in animals. Psychology Press Ltd, East Sussex, pp 295-320, 2000) that pictures and objects may be confused, perceived as independent or equivalent. In three experiments, bumblebees were given discrimination training and unrewarded testing in a radial maze. In the first experiment, preferences between artificial flowers and photographs of those flowers revealed a significant learned preference for the stimulus rewarded during training: no confusion following training. In the second experiment, bees did transfer learning from artificial flowers to photographs: some commonality between an object and photograph was perceived. In the third experiment, bees spontaneously generalized a learned preference for one artificial flower to its silhouette, but only for one of two flowers used in training. No generalization was obtained to drawn images. Some transfer between image and object is exhibited, likely by low-level feature matching, but transfer is poor with degraded images, cautioning against extrapolation of picture-based responding to natural correspondents. Despite evidence that bees exhibit some transfer while retaining discrimination, it is likely that the observed response is due to generalization more akin to confusion than true equivalence. Furthermore, although 2D patterning cues (line, edge and shade) provide discriminable cues for bees between 2D stimuli, it is not here supported that such features are perceived as equivalent to the intended floral structures.

Differential effects of metal contamination on the transcript expression of immune- and stress-response genes in the Sydney Rock oyster, Saccostrea glomerata.

Environmental contamination by metals is a serious threat to the biological sustainability of coastal ecosystems. Our current understanding of the potential biological effects of metals in these ecosystems is limited. This study tested the transcriptional expression of immune- and stress-response genes in Sydney Rock oysters (Saccostrea glomerata). Oysters were exposed to four metals (cadmium, copper, lead and zinc) commonly associated with anthropogenic pollution in coastal waterways. Seven target genes (superoxide dismutase, ferritin, ficolin, defensin, HSP70, HSP90 and metallothionein) were selected. Quantitative (real-time) PCR analyses of the transcript expression of these genes showed that each of the different metals elicited unique transcriptional profiles. Significant changes in transcription were found for 18 of the 28 combinations tested (4 metals × 7 genes). Of these, 16 reflected down-regulation of gene transcription. HSP90 was the only gene significantly up-regulated by metal contamination (cadmium and zinc only), while defensin expression was significantly down-regulated by exposure to all four metals. This inhibition could have a significant negative effect on the oyster immune system, promoting susceptibility to opportunistic infections and disease.

Proteomic analysis of Sydney Rock oysters (Saccostrea glomerata) exposed to metal contamination in the field.

This study used proteomics to assess the impacts of metal contamination in the field on Sydney Rock oysters. Oysters were transplanted into Lake Macquarie, NSW, for two weeks in both 2009 and 2010. Two-dimensional electrophoresis identified changes in protein expression profiles of oyster haemolymph between control and metal contaminated sites. There were unique protein expression profiles for each field trial. Principal components analysis attributed these differences in oyster proteomes to the different combinations and concentrations of metals and other environmental variables present during the three field trials. Identification of differentially expressed proteins showed that proteins associated with cytoskeletal activity and stress responses were the most commonly affected biological functions in the Sydney Rock oyster. Overall, the data show that proteomics combined with multivariate analysis has the potential to link the effects of contaminants with biological consequences.

Proteomic discovery of biomarkers of metal contamination in Sydney Rock oysters (Saccostrea glomerata).

In the current study we examined the effects of metal contamination on the protein complement of Sydney Rock oysters. Saccostrea glomerata were exposed for 4 days to three environmentally relevant concentrations (100 µg/l, 50 µg/l and 5 µg/l) of cadmium, copper, lead and zinc. Protein abundances in oyster haemolymph from metal-exposed oysters were compared to those from non-exposed controls using two-dimensional electrophoresis to display differentially expressed proteins. Differentially expressed proteins were subsequently identified using tandem mass spectrometry (LC-MS/MS), to assign their putative biological functions. Unique sets of differentially expressed proteins were affected by each metal, in addition to proteins that were affected by more than one metal. The proteins identified included some that are commonly associated with environmental monitoring, such as HSP 70, and other novel proteins not previously considered as candidates for molecular biomonitoring. The most common biological functions of proteins were associated with stress response, cytoskeletal activity and protein synthesis.

A proteomic analysis of the effects of metal contamination on Sydney Rock Oyster (Saccostrea glomerata) haemolymph.

The current study uses proteomics to assess the effects of metal contamination on Sydney Rock oyster haemolymph. Saccostrea glomerata were exposed in aquaria for four days to three environmentally relevant metals (copper, lead or zinc). Oyster haemolymph proteins from metal-exposed oysters were then compared to haemolymph from non-exposed controls using 2-dimensional electrophoresis to identify proteins that differed significantly in intensity. These proteins were then subjected to tandem mass spectrometry so that putative protein identities could be assigned. The data suggest that there are unique protein expression profiles for each metal. Exposure to 100 µg/l of copper, lead or zinc yielded a total of 25 differentially expressed proteins. However, only one of these protein spots exhibited altered intensities in response to all three metals. Eighteen of the 25 spots were significantly affected by just one of the three metals. Differentially expressed proteins were assigned to five different categories of biological function. Proteins affecting shell properties were the most common functional group accounting for 34% of the identified proteins. Cytoskeletal activities and metabolism/stress responses each accounted for a further 25% of the proteins.