Top-Down Attentional Processes Modulate the Coding of Atypical Biological Motion Kinematics in the Absence of Motor Signals

The acquisition of sensorimotor parameters that control goal-directed motor behaviors occurs by observing another person in the absence of efferent and afferent motor signals. This is observational practice. During such observation, biological motion properties associated with the observed person are coded into a representation that controls motor learning. Understanding the underlying processes, specifically associated with coding biological motion, has theoretical and practical significance. Here, we examined the following questions. Experiment 1: Are the underlying velocity characteristics associated with observed biological motion kinematics imitated? Experiment 2: Is attention involved in imitating biological motion kinematics? Experiment 3: Can selective attention modulate how biological motion kinematics are imitated/represented? To this end, participants practiced by observing a model performing a movement sequence that contained typical or atypical biological motion kinematics. The differences in kinematics were designed to dissociate the movement constraints of the task and the anatomical constraints of the observer. This way, we examined whether novel motor behaviors are acquired by adopting prototypical movements or coding biological motion. The kinematic analyses indicated the timing and spatial position of peak velocity were represented. Using a dual-task protocol, we attenuated the coding of biological motion kinematics (Experiment 2) and augmented coding using a selective attention protocol (Experiment 3). Findings indicated that velocity characteristics of biological motion kinematics are coded during observational practice, most likely through bottom-up sensorimotor processes. By modulating motion coding using 2 attentional protocols, we showed that bottom-up processes are influenced by input modulation, which is consistent with top-down control during observational practice

Impression or expression? The influence of self-monitoring on the social modulation of motor contagion

Social primes (pro-social, anti-social) can modulate mimicry behaviour. To date, these social modulation effects have been explained by the primed incentive to affiliate with another (Social Top-Down Response Modulation; STORM) and the primed active-self-concept leading to behaviour that is either consistent or inconsistent with the prime-construct (Active-Self account). The present study was designed to explore the explanatory power for each of these accounts, and thereby gain a greater understanding of how social modulation unfolds. To do this, we assessed social modulation of motor contagion in individuals high or low in self-monitoring. It was reasoned that high self-monitors would modulate mimicry according to the primed social incentive, whereas low self-monitors would modulate according to the primed active-self-concept. Participants were primed with a pro-social and anti-social cue in the first-person and third-person perspective. Next, they completed an interpersonal observation-execution task featuring the simultaneous observation and execution of arm movements that were either congruent or incongruent to each other. Results showed increased incongruent movement deviation (motor contagion) for the anti-social compared to the pro-social prime in the high self-monitors only. Findings support the STORM account of mimicry by showing observers modulate behaviour based on the social incentive underpinning an interpersonal exchange

Top-down and bottom-up processes during observation: Implications for motor learning

Neurophysiological and behavioural research has linked observational practice to a 2 mirroring mechanism encompassing the action-observation network (AON). Although the 3 original findings indicate that biological stimuli alone activate the AON, recent evidence 4 has shown sensitivity to non-biological stimuli. Thus, the AON is suggested to be 5 influenced by interacting bottom-up and top-down processes. In this review, we describe 6 the multi-functional properties of the AON, and discuss the implications for observational 7 practice and subsequent motor learning

Osteoarthritis as an Enhanceropathy: Gene Regulation in Complex Musculoskeletal Disease

\ua9 The Author(s) 2024.Purpose of Review: Osteoarthritis is a complex and highly polygenic disease. Over 100 reported osteoarthritis risk variants fall in non-coding regions of the genome, ostensibly conferring functional effects through the disruption of regulatory elements impacting target gene expression. In this review, we summarise the progress that has advanced our knowledge of gene enhancers both within the field of osteoarthritis and more broadly in complex diseases. Recent Findings: Advances in technologies such as ATAC-seq have facilitated our understanding of chromatin states in specific cell types, bolstering the interpretation of GWAS and the identification of effector genes. Their application to osteoarthritis research has revealed enhancers as the principal regulatory element driving disease-associated changes in gene expression. However, tissue-specific effects in gene regulatory mechanisms can contribute added complexity to biological interpretation. Summary: Understanding gene enhancers and their altered activity in specific cell and tissue types is the key to unlocking the genetic complexity of osteoarthritis. The use of single-cell technologies in osteoarthritis research is still in its infancy. However, such tools offer great promise in improving our functional interpretation of osteoarthritis GWAS and the identification of druggable targets. Large-scale collaborative efforts will be imperative to understand tissue and cell-type specific molecular mechanisms underlying enhancer function in disease

The physiological expression of inducible nitric oxide synthase (iNOS) in the human colon

Inducible nitric oxide synthase (iNOS) is expressed in the colonic epithelium in both inflammatory bowel disease and colorectal cancer. Nitric oxide (NO), the product of this enzyme, has been implicated in the pathogenesis of both conditions. However, there are conflicting data on whether iNOS is expressed in the normal, uninflamed human colon. To evaluate the expression of iNOS in histologically normal, non-inflamed human colonic mucosa. Reverse transcription polymerase chain reaction (RT-PCR), immunoblotting, and immunohistochemistry were used to investigate the expression of iNOS in 17 histologically normal specimens obtained at colectomy performed for colorectal neoplasia. In addition, 16 endoscopic mucosal biopsies, taken from normal individuals, were also evaluated. Eleven surgical specimens and 16 endoscopic biopsies from patients with refractory ulcerative colitis were used as inflammatory controls. All types of specimens expressed iNOS mRNA. Immunoblotting revealed a protein of approximately 130 kDa consistent with iNOS in mucosal extracts of 77% of normal individuals, and 85% of diseased controls. Immunolabelling localised this protein to the surface epithelium in most of the normal specimens and also to the crypt epithelium and inflammatory cells in the diseased controls. These findings provide evidence that iNOS is often expressed in the surface epithelium of non-inflamed human colon, suggesting that it is induced by local luminal factors, such as bacterial lipopolysaccharide (endotoxin). The resultant NO produced at this site might act as an oxidative barrier, reducing bacterial translocation and providing a means of defence against pathogenic microorganisms

A new factor in UK students’ university attainment: The relative age effect reversal?

Purpose – The purpose of this paper is to study relative age effects (RAEs) in a selected sample of university students. The majority of education systems across the globe adopt age-related cut-off points for eligibility. This strategy has received criticism for (dis)advantaging those older children born closer to the “cut-off” date for entry into an academic year and for promoting the existence of RAEs. To date, there are only two studies which have examined the relative age phenomenon in a university setting specifically. Design/methodology/approach – Data of student records from the years 2006-2009 were analysed. Specifically this included date of birth, The Universities and Colleges Admissions Service (UCAS) entry points, gender, grade point averages and final year degree classification. Findings – Analysis of data collected from 460 university students revealed a significant RAE reversal. Specifically, relatively younger students achieved significantly higher first-class honours degrees than relatively older students (p < 0.01). Research limitations/implications – Limitations include the following: the sample was modest and restricted to only 460 students located within one of the universities five faculties. Recent RAE studies in education have recruited thousands of students; therefore, these findings may not be totally representative of the broader UK university population. Originality/value – This is only the second UK-based study to examine RAEs from a university perspective. The findings highlight an interesting and new insight into the RAE phenomenon and one that warrants further scientific attention

Behaviourism, Constructivism and Sports Coaching Pedagogy: A Conversational Narrative in the Facilitation of Player Learning

To develop our understanding about how learning theory can help to make sense of and inform the facilita- tion of player learning, this article presents a fictitious discussion, which takes place following a postgraduate sports coaching lecture on learning theories, pedagogy and practice. Following the lecture, Coach Educator (CE) joins two group members for a coffee to listen to their thoughts, experiences, and coaching practices in relation to pertinent player learning theory. Behaviourist Coach (BC) discusses his approach to coaching and how he has come to coach in this way; and his practices that conform to behaviourist learning theory. When BC has finished sharing his views and practices, CE then invites the other student to contribute to the discussion. Constructivist Coach (CC) recognises that his philosophical beliefs about the facilitation of player learning are vastly different to those of BC. As such, CC decides to share his approach to coaching, which aligns itself with constructivist learning theory. It is hoped that this dialogue will not only further theorise the facilitation of player learning, but do so in a way that helps coaching practitioners make the connection between learning theory and coaching practice

A paleolimnological reconstruction of mid and late holocene climate change in South Georgia

South Georgia is located at the barrier between Antarctica and the mid-latitudes which makes it a key location to determine the main drivers of past and present-day climate variability and to assess whether the climate in the South Atlantic was synchronous with Antarctica or South America. Here we performed a sedimentological, high resolution (ITRAX) geochemical, and fossil diatom and pigment analysis of a 5.41 m long, ca. 8000 cal yr BP, sediment core from Fan Lake, Annenkov Island, South Georgia (54°29’0’’S, 37°5’0’’W) in an attempt to separate the influence of Holocene palaeoclimatic variability from changes in catchment stability and glacier activity. While radiocarbon ages of events in the top 250 cm (c. 4 ka) of this core appear to be broadly in line with some other studies on South Georgia, the chronology of the lower half still poses several questions. The main lithological division in the profile is marked by the establishment of finely laminated sedimentation at c. 250 cm (4000 yrs BP) and is also picked out by the diatom and pigment analysis. This change is characterized by a reduction to low stable magnetic susceptibility values and a step-change increase in organic matter, and is most likely related to deglaciation of the lake catchment during the ‘Mid Holocene Hypsithermal’. Although the diatom composition is dominated by a single species (i.e., Cyclotella stelligera), relatively minor, but sometimes significant, fluctuations in other diatom species occur in the top 250 cm (mid-late Holocene). Interestingly, the most remarkable change in the diatom record occurs at c. 100 cm (1000 cal yr BP) and coincides with an increase in general lake productivity. We link these changes to increased catchment disturbance at c. 1000 cal yr BP, which is possibly associated with deglaciation following one of four relatively minor ‘post-cooling events’ during the late Holocene

Water intoxication presenting as maternal and neonatal seizures: a case report.

Introduction We present an unusual case of fitting in the mother and newborn child, and the challenges faced in the management of their hyponatraemia due to water intoxication. Case presentation A previously well 37-year-old, primigravid Caucasian woman presented with features mimicking eclampsia during labour. These included confusion, reduced consciousness and seizures but without a significant history of hypertension, proteinuria or other features of pre-eclampsia. Her serum sodium was noted to be low at 111 mmol/litre as was that of her newborn baby. She needed anti-convulsants with subsequent intubation to stop the fitting and was commenced on a hypertonic saline infusion with frequent monitoring of serum sodium. There is a risk of long-term neurological damage from central pontine myelinolysis if the hyponatraemia is corrected too rapidly. Mother and baby went on to make a full recovery without any long-term neurological complications. Conclusion There is little consensus on the treatment of life-threatening hyponatraemia. Previous articles have outlined several possible management strategies as well as their risks. After literature review, an increase in serum sodium concentration of no more than 8–10 mmol/litre in 24 hours is felt to be safe but can be exceeded with extreme caution if life-threatening symptoms do not resolve. Formulae exist to calculate the amount of sodium needed and how much hypertonic intravenous fluid will be required to allow safer correction. We hypothesise the possible causes of hyponatraemia in this patient and underline its similarity in symptom presentation to eclampsia

The influence of environmental context in interpersonal observation-execution.

Cyclical upper-limb movements involuntarily deviate from a primary movement direction when the actor concurrently observes incongruent biological motion. We examined whether environmental context influences such motor interference during interpersonal observation-execution. Participants executed continuous horizontal arm movements while observing congruent horizontal or incongruent curvilinear biological movements with or without the presence of an object positioned as an obstacle or distractor. When observing a curvilinear movement, an object located within the movement space became an obstacle, and thus, the curvilinear trajectory was essential to reach into horizontal space. When acting as a distractor, or with no object, the curvilinear trajectory was no longer essential. For observing horizontal movements, objects were located at the same relative locations as in the curvilinear movement condition. We found greater involuntary movement deviation when observing curvilinear compared to the horizontal movements. Also, there was an influence of context only when observing horizontal movements, with greater deviation exhibited in the presence of a large obstacle. These findings suggest the influence of environmental context is underpinned by the (mis-)matching of observed and executed actions as incongruent biological motion is primarily coded via bottom-up sensorimotor processes, whilst the congruent condition incorporates surrounding environmental features to modulate the bottom-up sensorimotor processes