Effects of caffeine on reaction time are mediated by attentional rather than motor processes

Background Caffeine has a well-established effect on reaction times (RTs) but the neurocognitive mechanisms underlying this are unclear. Methods In the present study, 15 female participants performed an oddball task after ingesting caffeine or a placebo, and electroencephalographic data were obtained. Single-trial P3b latencies locked to the stimulus and to the response were extracted and mediation models were fitted to the data to test whether caffeine’s effect on RTs was mediated by its effect on either type of P3b latencies. Results Stimulus-locked latencies showed clear evidence of mediation, with approximately a third of the effect of caffeine on RTs running through the processes measured by stimulus-locked latencies. Caffeine did not affect response-locked latencies, so could not mediate the effect. Discussion These findings are consistent with caffeine’s effect on RTs being a result of its effect on perceptual-attentional processes, rather than motor processes. The study is the first to apply mediation analysis to single-trial P3b data and this technique holds promise for mental chronometric studies into the effects of psychopharmacological agents. The R code for performing the single trial analysis and mediation analysis are included as supplementary materials

The RESET project: constructing a European tephra lattice for refined synchronisation of environmental and archaeological events during the last c. 100 ka

This paper introduces the aims and scope of the RESET project (. RESponse of humans to abrupt Environmental Transitions), a programme of research funded by the Natural Environment Research Council (UK) between 2008 and 2013; it also provides the context and rationale for papers included in a special volume of Quaternary Science Reviews that report some of the project's findings. RESET examined the chronological and correlation methods employed to establish causal links between the timing of abrupt environmental transitions (AETs) on the one hand, and of human dispersal and development on the other, with a focus on the Middle and Upper Palaeolithic periods. The period of interest is the Last Glacial cycle and the early Holocene (c. 100-8 ka), during which time a number of pronounced AETs occurred. A long-running topic of debate is the degree to which human history in Europe and the Mediterranean region during the Palaeolithic was shaped by these AETs, but this has proved difficult to assess because of poor dating control. In an attempt to move the science forward, RESET examined the potential that tephra isochrons, and in particular non-visible ash layers (cryptotephras), might offer for synchronising palaeo-records with a greater degree of finesse. New tephrostratigraphical data generated by the project augment previously-established tephra frameworks for the region, and underpin a more evolved tephra 'lattice' that links palaeo-records between Greenland, the European mainland, sub-marine sequences in the Mediterranean and North Africa. The paper also outlines the significance of other contributions to this special volume: collectively, these illustrate how the lattice was constructed, how it links with cognate tephra research in Europe and elsewhere, and how the evidence of tephra isochrons is beginning to challenge long-held views about the impacts of environmental change on humans during the Palaeolithic. © 2015 Elsevier Ltd.RESET was funded through Consortium Grants awarded by the Natural Environment Research Council, UK, to a collaborating team drawn from four institutions: Royal Holloway University of London (grant reference NE/E015905/1), the Natural History Museum, London (NE/E015913/1), Oxford University (NE/E015670/1) and the University of Southampton, including the National Oceanography Centre (NE/01531X/1). The authors also wish to record their deep gratitude to four members of the scientific community who formed a consultative advisory panel during the lifetime of the RESET project: Professor Barbara Wohlfarth (Stockholm University), Professor Jørgen Peder Steffensen (Niels Bohr Institute, Copenhagen), Dr. Martin Street (Romisch-Germanisches Zentralmuseum, Neuwied) and Professor Clive Oppenheimer (Cambridge University). They provided excellent advice at key stages of the work, which we greatly valued. We also thank Jenny Kynaston (Geography Department, Royal Holloway) for construction of several of the figures in this paper, and Debbie Barrett (Elsevier) and Colin Murray Wallace (Editor-in-Chief, QSR) for their considerable assistance in the production of this special volume.Peer Reviewe

Area-level exposures for social epidemiology in Wales

I have created exposure data for small areas in Wales for a number of projects and will store them all here. You are very welcome to use them. If you do, please cite the relevant paper: Social capital by Welsh MSOA: Saville CWN. Estimating ecological social capital using multi-level regression with post-stratification: A spatial analysis of psychiatric admission rates in wales. Health & Place 2019;59:102187. doi:10.1016/j.healthplace.2019.102187 Economic and cultural capital by Welsh MSOA: Saville, CWN. & Mann, R (2022) Cross-level group density interactions on mental health for cultural, but not economic, components of social class. Social Science and Medicine, 296, 114790. https://doi.org/10.1016/j.socscimed.2022.114790 Please contact me on [email protected] with any questions. Thanks! Chri

A comprehensive systematic review and multilevel meta-analysis of the ethnic density effect in psychosis

Background An ethnic density effect in psychosis has been observed whereby the risk of psychosis in minority group individuals is inversely related to the neighbourhood-level proportion of others belonging to the same group. However, there is conflicting evidence over whether this effect differs between minority groups and limited investigation into other moderators. Aims To conduct a comprehensive systematic review and meta-analysis of the ethnic density effect in psychosis and examine moderators. Method Four databases were systematically searched. A narrative review was conducted, and a three-level meta-analysis was performed. The potential moderating effect of crudely and specifically defined minority groups was assessed. Country, time, area size, and whether studies used clinical or non-clinical outcomes were also tested as moderators. Results Thirty-one studies were included in the narrative review and ten in the meta-analysis. A ten percentage-point decrease in own-group density was associated with a 20% increase in psychosis risk [OR=1.20 (CI95%=1.09-1.32), p<0.001]. The pooled effect was moderated by crudely defined minority groups [F6,68=6.86, p<0.001], with the strongest associations observed in Black populations, followed by a White Other sample. Greater heterogeneity was observed when specific minority groups were assessed [F25,49=7.26, p<0.001]. Conclusions This is the first review to provide meta-analytic evidence that the risk of psychosis posed by lower own-group density areas is not equally distributed across minority groups. The most robust associations were observed in Black individuals. Heterogeneity in effect sizes may reflect distinctive social experiences of specific minority groups. Mechanisms are discussed, along with the implications of findings and suggestions for future research

The survivability of dialectical behaviour therapy programmes: a mixed methods analysis of barriers and facilitators to implementation within UK healthcare settings

Abstract Background Dialectical Behaviour Therapy (DBT) is an evidence-based intervention that has been included in the National Institute of Health and Care Excellence guidelines as a recommended treatment for Borderline Personality Disorder in the UK. However, implementing and sustaining evidence-based treatments in routine practice can be difficult to achieve. This study compared the survival of early and late adopters of DBT as well as teams trained via different training modes (on-site versus off-site), and explored factors that aided or hindered implementation of DBT into routine healthcare settings. Methods A mixed-method approach was used. Kaplan-Meier survival analyses were conducted to quantify and compare survivability as a measure of sustainability between early and late implementers and those trained on- and off-site. An online questionnaire based on the Consolidated Framework for Implementation Research was used to explore barriers and facilitators in implementation. A quantitative content analysis of survey responses was carried out. Results Early implementers were significantly less likely to survive than late implementers, although, the effect size was small. DBT teams trained off-site were significantly more likely to survive. The effect size for this difference was large.  An unequal amount of censored data between groups in both analyses means that findings should be considered tentative. Practitioner turnover and financing were the most frequently cited barriers to implementation. Individual characteristics of practitioners and quality of the evidence base were the most commonly reported facilitators to implementation. Conclusions A number of common barriers and facilitators to successful implementation of DBT were found among DBT programmes. Location of DBT training may mediate programme survival

Identification of neuromotor deficits common to autism spectrum disorder and attention deficit/hyperactivity disorder, and imitation deficits specific to autism spectrum disorder

Deficits in motor and imitation abilities are a core finding in autism spectrum disorders (ASD), but impaired motor functions are also found in attention deficit/hyperactivity disorder (ADHD). Given recent theorising about potential aetiological overlap between the two disorders, the present study aimed to assess difficulties in motor performance and imitation of facial movements and meaningless gestures in a sample of 24 ADHD patients, 22 patients with ASD, and 20 typically developing children, matched for age (6-13 years) and similar in IQ (> 80). Furthermore, we explored the impact of comorbid ADHD symptoms on motor and imitation performance in the ASD sample and the interrelationships between the two groups of variables in the clinical groups separately. The results show motor dysfunction was common to both disorders, but imitation deficits were specific to ASD. Together with the pattern of interrelated motor and imitation abilities, which we found exclusively in the ASD group, our findings suggest complex phenotypic, and possibly aetiological, relationships between the two neurodevelopmental conditions

A neural analogue of the worst performance rule: Insights from single-trial event-related potentials

The worst performance rule is the tendency for participants' slowest reaction times to correlate more with psychometric intelligence than their faster reaction times. Reaction times, however, are influenced by the duration of multiple perceptual, attentional, and motor sub-processes, and it is unclear whether the same pattern exists in these sub-processes as well. We used single-trial event-related potentials to identify whether a worst performance rule pattern could be found in stimulus and response-locked P3b latency distributions and scores on a test of non-verbal psychometric intelligence. Fifty participants carried out a set of working memory oddball tasks, while electroencephalographic data were collected, and the British Version of the Intelligence Structure Test, in a separate session. Single-trial P3b latencies were identified in stimulus and response-locked data and a novel quantile bootstrapping method was used to identify which quantiles of the P3b latency distributions correlated most with test scores. In stimulus-locked data, correlations between quantile mean and test scores became more negative with increasing quantile, showing clear evidence of a worst performance rule pattern. In response-locked data, low scorers showed more extreme latencies in both tails of the distribution. However we did not observe a worst performance rule in behavioural data. These data suggest that psychometric intelligence is also associated with response-related processes, which may also contribute to the association between psychometric intelligence and reaction time variability. (C) 2015 Elsevier Inc. All rights reserved

ADHD Traits in German School-Aged Children: Validation of the German Strengths and Weaknesses of ADHS Symptoms and Normal Behavior (SWAN-DE) Scale

Objective: The Strengths and Weaknesses of ADHS-Symptoms and Normal Behavior (SWAN) Scale has been developed to support the dimensional assessment of ADHD symptoms by capturing variance on both poles of the ADHD continuum. The present study provides the first validation of the German version of SWAN (SWAN-DE). Method: Based on a sample of N-1 = 343 children from the general population and N-2 = 62 children with ADHD, both aged between 8 and 18 years, normality, internal consistency, test-retest reliability, and different validity indices were examined. Results: SWAN was characterized by normally distributed scores, good to excellent reliability, and factorial validity. It showed high diagnostic utility in discriminating between patients with ADHD and healthy controls and significant correlations to related clinical scales and neuropsychological constructs, such as intra-subject variability. Conclusion: The present study reveals the excellent psychometric properties of SWAN-DE, which can now be usefully applied in the German-speaking countries as well as in cross-national studies