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Focusing attention in working and long-term memory through dissociable mechanisms.
We developed an experimental approach to compare how attentional orienting facilitates retrieval from spatial working memory (WM) and long-term memory (LTM), and how selective attention within these two memory types impacts incoming sensory information processing. In three experiments with healthy young adults, retrospective attention cues prioritize an item represented in WM or LTM. Participants then retrieve a memory item or perform a perceptual task. The retrocue is informative for the retrieval task but not for the perceptual task. We show that attentional orienting benefits performance for both WM and LTM, with stronger effects for WM. Eye-tracking reveals significant gaze shifts and microsaccades correlated with attention in WM, but no statistically significant gaze biases were found for LTM. Visual discrimination of unrelated visual stimuli is consistently improved for items matching attended WM locations. Similar effects occur at LTM locations but less consistently. The findings suggest at least partly dissociable attention-orienting processes for different memory types. Although our conclusions are necessarily constrained to the type of WM and LTM representations relevant to our task, they suggest that, under certain conditions, attentional prioritization in LTM can operate independently from WM. Future research should explore whether similar dissociations extend to non-spatial or more complex forms of LTM.
Current and prospective roles of magnetic resonance imaging in mild traumatic brain injury
There is unmet clinical need for biomarkers to predict recovery or the development of long-term sequelae of mild traumatic brain injury, a highly prevalent condition causing a constellation of disabling symptoms. A substantial proportion of patients live with long-lasting sequelae affecting their quality of life and ability to work. At present, symptoms can be assessed through clinical tests; however, there are no imaging or laboratory tests fully reflective of pathophysiology routinely used by clinicians to characterize post-concussive symptoms. Magnetic resonance imaging has potential to link subtle pathophysiological alterations to clinical outcomes. Here, we review the state of the art of MRI research in adults with mild traumatic brain injury and provide recommendations to facilitate transition into clinical practice. Studies utilizing MRI can inform on pathophysiology of mild traumatic brain injury. They suggest presence of early cytotoxic and vasogenic oedema. They also show that mild traumatic brain injury results in cellular injury and microbleeds affecting the integrity of myelin and white matter tracts, all processes that appear to induce delayed vascular reactions and functional changes. Crucially, correlates between MRI parameters and post-concussive symptoms are emerging. Clinical sequences such as T1-weighted MRI, susceptibility-weighted MRI or fluid attenuation inversion recovery could be easily implementable in clinical practice, but are not sufficient, in isolation for prognostication. Diffusion sequences have shown promises and, although in need of analysis standardization, are a research priority. Lastly, arterial spin labelling is emerging as a high-utility research as it could become useful to assess delayed neurovascular response and possible long-term symptoms.
Contributed Talks I: Information integration in early visual processing revealed by Vernier thresholds.
Vernier acuity thresholds represent minimal detectable spatial offset between two closely placed targets. We previously showed that Vernier thresholds for a Poisson-limited ideal observer with access to the cone excitations are determined jointly by duration and contrast through the quantity duration x contrast squared. Here we measured thresholds in 7 human observers for combinations of stimulus contrast (100%, 50%, 25%, and 12.5%) and duration (16.7 ms, 66.7 ms, 266.7 ms and 1066.7 ms), while fixing other stimulus properties (foveal viewing; two achromatic vertical bars; length 10.98 arcmin; width 4.39 arcmin; vertical gap 0.878 arcmin). The combinations of duration and contrast were chosen to form four groups of constant duration x contrast squared. Thresholds were a decreasing function of duration x contrast squared. A one-way between observers ANOVA does not reject the hypothesis threshold duration and contrast are integrated through the quantity duration x contrast squared, but the residuals obtained by predicting threshold within each of the four groups by its mean varied systematically with duration, indicating that duration x contrast squared does not fully summarize the information integration. This difference between ideal and human performance indicates that post-receptoral factors not included in the ideal observer model, such as temporal filtering, affect human performance. These factors will be included in future modeling.
Contributed Talks I: Fixational eye movements and retinal adaptation: optimizing drift to maximize information acquisition.
Fixational eye movements (FEMs) are small, fluctuating eye motions when fixating on a target. Given our visual system is evolved, we may ask why FEMs are beneficial and whether they are optimal. A possible reason for FEMs is overcoming retinal adaptation (fading perception of a fixed image). We present a simple model system allowing theoretical investigation of FEM influence on information about an external stimulus. The model incorporates temporal stimulus modulation, retinal image motion due to the drift component of FEMs, blurring due to optics and receptor size, uniform sampling by the receptor array, adaptation via a bandpass temporal filter, and added noise. We investigate how elements of the model mediate the information transmitted, via: i) mutual information between visual system response and external stimulus, ii) direct estimation of stimulus from the system response, and iii) contrast threshold for signal detection. For all these we find a common quantity that must be maximized. For each spatial frequency this quantity is a summed power transmitted due to stimulus temporal modulation and phase shifts from FEMs, when passed through the temporal filter. We demonstrate that the information transmitted can be increased by adding local persistence to an underlying diffusive process. We also quantify the contribution of FEMs to signal detection for targets of different size and duration; such predictions provide a qualitative account of human psychophysical performance.
Poster Session: The effect of fixational eye-movements on the temporal summation at detection threshold: A simulation study.
We explored how fixational eye movements (FEMs) affect threshold temporal summation of increment pulses using realistic simulations of early visual processing. Using the Image Systems Engineering Toolbox for Biology, we assessed performance in a spatial 2AFC increment detection task, where the observer identified whether a stimulus appeared on the left or right. The signal-known-exactly ideal observer was trained on the noise-free photocurrent output of the cone mosaic for both stimulus alternatives, with performance calculated using noisy instances of photocurrents, given FEMs knowledge. The stimuli, modelled as 0.24x2.2 arcmin increments of 543 nm light presented via an AOSLO, included both a single 2 ms flash and pairs of flashes separated by interstimulus intervals (ISI) of 17 ms, 33 ms, 100 ms, or 300 ms. Detection thresholds, defined as the stimulus contrast corresponding to 75% correct, were assessed with and without FEMs. Without FEMs, thresholds for detecting two flashes separated by 17-100 ms slightly increased with ISI but remained lower than those for a single flash. With FEMs, the modelled differences between single- and two-flash thresholds were less pronounced, suggesting that, at the level of photocurrent signals, FEMs reduce the benefits of temporal summation for detection. Future work will quantify this reduction by simulating FEMs with varying velocities and explore if adding a temporal adaptation stage improves effect of FEMs' on performance.
A cognitive map for value-guided choice in the ventromedial prefrontal cortex.
The prefrontal cortex (PFC) is crucial for economic decision-making. However, how PFC value representations facilitate flexible decisions remains unknown. We reframe economic decision-making as a navigation process through a cognitive map of choice values. We found rhesus macaques represented choices as navigation trajectories in a value space using a grid-like code. This occurred in ventromedial PFC (vmPFC) local field potential theta frequency across two datasets. vmPFC neurons deployed the same grid-like code and encoded chosen value. However, both signals depended on theta phase: occurring on theta troughs but on separate theta cycles. Finally, we found sharp-wave ripples-a key signature of planning and flexible behavior-in vmPFC. Thus, vmPFC utilizes cognitive map-based computations to organize and compare values, suggesting an alternative architecture for economic choice in PFC.
Thermal constraints on Middle Pleistocene hominin brain evolution and cognition
High latitude habitats are subject to thermally-driven energetic constraints that make their occupation challenging. This is likely to have had a particularly significant impact on energy-expensive tissue like the brain, especially during periods of lower global temperatures during the Mid-Pleistocene Ice Ages. I analyse data on endocranial volumes for archaic humans (Homo heidelbergensis, H. neanderthalensis and allies) to show (1) that cranial volumes were typically smaller at high latitudes than in the tropics and (2) that they declined during cold phases and increased during warm phases of the Middle Pleistocene Ice Ages. Within this broad pattern, there is a significant uplift in cranial volumes after 400 ka that seems to coincide with widespread presence of hearths at high latitudes, suggesting that hominin populations might have gained at least partial release from this constraint through cultural control over fire. While this might pinpoint the time at which hominins first began to cook on a regular basis, fire offers other important benefits (notably warmth and extending the length of the working day) that might have played an equally important role in buffering populations against thermal stresses. The larger brain sizes that this made possible have implications for social cognitive capacities like mentalising, that in turn have implications for language skills, cultural behaviour and social group size.
Multimodal population study reveals the neurobiological underpinnings of chronotype.
The rapid shifts in society have altered human behavioural patterns, with increased evening activities, increased screen time and changed sleep schedules. As an explicit manifestation of circadian rhythms, chronotype is closely intertwined with physical and mental health. Night owls often exhibit unhealthier lifestyle habits, are more susceptible to mood disorders and have poorer physical fitness compared with early risers. Although individual differences in chronotype yield varying consequences, their neurobiological underpinnings remain elusive. Here we conducted a pattern-learning analysis with three brain-imaging modalities (grey matter volume, white-matter integrity and functional connectivity) and capitalized on 976 phenotypes in 27,030 UK Biobank participants. The resulting multilevel analysis reveals convergence on the basal ganglia, limbic system, hippocampus and cerebellum. The pattern derived from modelling actigraphy wearables data of daily movement further highlighted these key brain features. Overall, our population-level study comprehensively investigates chronotype, emphasizing its close connections with habit formation, reward processing and emotional regulation.
The fNIRS glossary project: a consensus-based resource for functional near-infrared spectroscopy terminology.
SIGNIFICANCE: A shared understanding of terminology is essential for clear scientific communication and minimizing misconceptions. This is particularly challenging in rapidly expanding, interdisciplinary domains that utilize functional near-infrared spectroscopy (fNIRS), where researchers come from diverse backgrounds and apply their expertise in fields such as engineering, neuroscience, and psychology. AIM: The fNIRS Glossary Project was established to develop a community-sourced glossary covering key fNIRS terms, including those related to the continuous-wave (CW), frequency-domain (FD), and time-domain (TD) NIRS techniques. APPROACH: The glossary was collaboratively developed by a diverse group of 76 fNIRS researchers, representing a wide range of career stages (from PhD students to experts) and disciplines. This collaborative process, structured across five phases, ensured the glossary's depth and comprehensiveness. RESULTS: The glossary features over 300 terms categorized into six key domains: analysis, experimental design, hardware, neuroscience, mathematics, and physics. It also includes abbreviations, symbols, synonyms, references, alternative definitions, and figures where relevant. CONCLUSIONS: The fNIRS glossary provides a community-sourced resource that facilitates education and effective scientific communication within the fNIRS community and related fields. By lowering barriers to learning and engaging with fNIRS, the glossary is poised to benefit a broad spectrum of researchers, including those with limited access to educational resources.
Effects of the Incredible Years parenting program on sibling conduct problems: A latent transition analysis
Background: Behavioral parenting programs are a primary strategy used to reduce children's conduct problems. Although behavior problems in siblings may co-occur, behavioral parenting program trials typically report outcomes for one child per family (the index child), with potential program effects on any non-targeted sibling largely neglected. This study examined co-occurring patterns of index child and non-targeted sibling conduct problems, and how parental participation in the Incredible Years (IY) program changes these patterns. Methods: We used individual participant data pooled across three randomized trials of the IY parenting program in England, Wales, and Ireland, with data for the index child and one non-targeted sibling (N = 240 families, 480 children; index child: M age = 4.73, SD = 1.44, range 2–9 years, 62% male; non-targeted sibling: M age = 5.94 years, SD = 3.15, range 6 months−15 years, 49% male). We used latent transition analysis to identify latent classes at both baseline and posttest based on families' combinations of index child and non-targeted sibling conduct problems. Results: We identified two classes with distinct patterns of co-occurring sibling dyad conduct problems: one with moderate clinical levels of index child conduct problems and non-clinical levels for the non-targeted sibling; and one with severe clinical levels for both children. In terms of the effects of IY, most intervention families maintained their patterns of sibling dyad conduct problems, but with lower levels across classes. Most intervention families reported improvements predominantly for the index child. However, a minority of families with severe baseline levels of conduct problems in both children moved to a class with non-clinical levels for both children. Conclusions: For most families, IY had limited effects on non-targeted sibling disruptive behavior. However, IY may reduce co-occurring sibling conduct problems for a small number of families with initially severe levels in both children.
Improving older people’s experiences and safety at transitions of care: the PACT mixed-methods study including RCT
Background Transitions from hospital to home are a risky time for older people (aged 75 years and older). Unplanned and often avoidable hospital re-admissions are therefore high in this group. This research aimed to understand if increased involvement of older people in their care in hospital would improve the safety and experience of care transitions. Objectives In six work packages we set out to: understand patient and carer involvement in and experience of care transitions explore staff experiences of delivering good transitional care develop and validate a new measure (the Partners at Care Transitions Measure) to assess patient experience and safety during care transitions create a theory and logic model to inform the co-designed transitions intervention followed by a formative evaluation test the feasibility of delivering a trial to evaluate the intervention evaluate the clinical- and cost-effectiveness of the transitions intervention with a parallel process evaluation. Design Qualitative methods (1 and 2), literature reviewing, Delphi techniques and validation testing (3), co-design (4), cluster feasibility trial (5) and cluster randomised controlled trial (6). Settings National Health Service acute hospital trusts, general practices, patients and carer homes across the north of England, United Kingdom. Participants Patients aged 75 years and older and their caregivers. National Health Service staff working in acute National Health Service trusts on wards delivering the intervention. Intervention ‘Your Care Needs You’ intervention to support patient and carer involvement in hospital care in preparation for returning home. This comprised fixed components: a booklet, an advice sheet for managing at home and a film; and flexible components: ongoing staff involvement of patients through multiple approaches. Implementation included a nominated lead, staff training and posters. Main outcome measures Primary outcome was unplanned 30-day hospital re-admissions. Secondary outcomes included: unplanned 60- and 90-day hospital re-admissions; quality of transition; health-related quality of life (EuroQol-5 Dimensions, five-level version); and self-reported healthcare resource use. Data sources National Health Service Secondary Use Services data and Hospital Episodes data for work package 2 and routinely recorded National Health Service acute trust hospital data on re-admissions for work packages 5 and 6. Review methods Systematic narrative review for preparatory work on patient involvement; narrative meta review of transitions interventions; scoping review of transitions measures. Results Work package 1: Six themes relating to patient experience of care transitions. Patient involvement in hospital care found to be challenging ‘work’ that was often invisible to staff. Work package 2: National Health Service staff reported that high-quality care transitions were facilitated primarily through trust and strong relationships. Work package 3: A measure of quality and safety of care transitions (Partners at Care Transitions Measure) developed and validated with good internal reliability and internal consistency. Work package 4: An intervention called ‘Your Care Needs You’ that required revisions to support implementation. Work package 5: Primary outcome data were collected for 90% of participants. Follow-up questionnaire response rates were lower than anticipated (75% vs. 85%). Information on the acceptability, usability and implementation of the intervention informed iterations to the intervention and implementation package. Work package 6: 4947 participants from 39 hospital wards took part in the main trial. Six hundred and thirteen participants from 35 wards took part in the nested cohort. No differences were observed in the primary outcome of unplanned re-admission (Y/N) at 30 days post discharge [17% experienced re-admission within 30 days in the ‘Your Care Needs You’ group, 18% in care-as-usual, odds ratio: (0.93; 95% confidence interval, 0.78 to 1.10; p = 0.372)], and also at 60 and 90 days post discharge but all results were in favour of the intervention with a reduction in total re-admissions of 13% over 90 days [incidence rate ratio: 0.87 (0.76 to 0.99), p = 0.039]. There was a statistically significant reduction in Partners at Care Transitions Measure safety concerns at 30 days post discharge. The intervention is likely to be cost-effective. Limitations The main trial was conducted during the COVID-19 pandemic which exacerbated staffing challenges and limited opportunities to enhance and support implementation of the intervention. Participant recruitment to the nested study was challenging, resulting in fewer patients than planned and a less diverse sample than that included in the primary cohort. Therefore, while our primary cohort is representative of the patients in the hospital during the trial period, the nested cohort may suffer from some bias. Conclusions The ‘Your Care Needs You’ intervention offers a way to support staff and patients/families to facilitate greater involvement in care. This research demonstrates that increased involvement in hospital care has the potential to improve safety at transitions. Finding ways to support staff to encourage better patient involvement could lead to even more benefits being realised. Future work Hospitals could consider involving volunteers in supporting greater patient and family involvement. There was some indication that the component of the intervention most favoured was the patient advice for discharge. Trial registration This trial is registered as Current Controlled Trials ISRCTN51154948 (WP5) and ISRCTN17062524 (WP6). Funding This award was funded by the National Institute for Health and Care Research (NIHR) Programme Grants for Applied Research programme (NIHR award ref: RP-PG-1214-20017) and is published in full in Programme Grants for Applied Research; Vol. 13, No. 4. See the NIHR Funding and Awards website for further award information.
Dynamic modulation of confidence based on the metacognitive skills of collaborators.
In collaborative decision-making contexts, people typically share their metacognitive experience of confidence to convey the degree of certainty in their decisions. To reach collective decisions, collaborators' individual beliefs can be aggregated and weighted according to their respective confidence, thereby enhancing group accuracy beyond individual capabilities. Previous joint decision-making studies have shown that individuals tend to adopt the same scale for communicating their levels of confidence. However, confidence judgments vary not only in terms of metacognitive bias, that is whether individuals tend to report generally low or high confidence, but also in terms of metacognitive accuracy, or how well the confidence judgments align with choice accuracy. In the first two experiments, where the metacognitive accuracy of the collaborator was manipulated and explicitly communicated to participants, individuals increased their average confidence levels as the metacognitive accuracy of the collaborator decreased, while their own metacognitive accuracy remained unaffected. Trial-wise analyses showed that participants differentially adapted their confidence after a collaborator made a wrong group decision, depending on the metacognitive accuracy of the collaborator. In two follow up studies, we showed that both manipulations (i.e. manipulating objective differences in the metacognitive accuracies of the collaborators and explicitly communicating these differences) were necessary for these effects to emerge. Our findings shed light on how collaborative decision-making contexts can dynamically affect metacognitive processes.
On Religious Influence in Bioethics: The Limits of Pluriversalism.
The World Congress of Bioethics held in Qatar in 2024 (WCB 2024) sparked controversy around the role of religion in bioethics, highlighting the need for critical discussions. During the congress, there was a strong push for incorporating religious values into bioethical discourse, raising questions about the validity and implications of such an approach. This paper examines the influence of religious thought on bioethical discussions, and the ongoing debate over the role of religious perspectives in this field. Here, we explore Jecker and colleagues' pluriversal framework, which was proposed at WCB 2024, espousing a bioethical discourse grounded in civility, respect for law, justice, non-domination, and toleration. While the framework aims to embrace the world's cultural and religious diversity, here, we suggest that it struggles with significant ethical inconsistencies, poses challenges for pluralistic dialogue, and may be hard to reconcile with human rights. Through an analysis of Jecker's principles and their application, we discuss the difficulty of integrating conflicting religious views with ethical values and with widely accepted human rights frameworks. We then proceed to examine how and why religions might exert undue influence on bioethics, and we argue for a different future for bioethics.
Practical routes to preregistration: a guide to enhanced transparency and rigour in neuropsychological research
Abstract Preregistration is the act of formally documenting a research plan before collecting (or at least before analysing) the data. It allows those reading a final research report to know which aspects of a study were decided before sight of the data, and which were added later. This enables informed evaluation of the severity with which scientific claims have been tested. We, as the British Neuropsychological Society Open Research Group, conducted a survey to explore awareness and adoption of open research practices within our field. Neuropsychology involves the study of relatively rare or hard-to-access participants, creating practical challenges that, according to our survey, are perceived as barriers to preregistration. We survey the available routes to preregistration, and suggest that the barriers are all surmountable in one way or another. However, there is a tension, in that higher levels of bias control require greater restriction over the flexibility of preregistered studies, but such flexibility is often essential for neuropsychological research. Researchers must therefore consider which route provides the right balance of rigour and pragmatic flexibility to render a preregistered project viable for them. By mapping out the issues and potential solutions, and by signposting relevant resources and publication routes, we hope to facilitate well-reasoned decision-making and empower neuropsychologists to enhance the transparency and rigour of their research. Although we focus neuropsychology, our guidance is applicable to any field that studies hard-to-access human samples, or involves arduous or expensive means of data collection.
The role of virtual wards in maternity in the United Kingdom.
Virtual wards are an initiative which aims to provide hospital care from the comfort of the patient's own home. Monitoring and additional services, such as intravenous drugs and fluids and blood tests can be undertaken through this system. Although virtual wards have been used in the UK since 2005 in specialties such as General Medicine, General Surgery and Paediatrics, their use in maternity has been more limited. This article aims to review their current use in the UK and beyond as well as to discuss some of the advantages and challenges they may pose to a maternity population.
Anxiety and Related Disorders During the Perinatal Period.
Anxiety and anxiety-related disorders are, as a group, the most common mental health conditions and are more common among women compared with among men. It is now evident that these disorders affect one in five pregnant and postpartum people and are more common than depression. For some disorders (e.g., obsessive-compulsive disorder), there is also evidence of an elevated risk for their development and exacerbation during perinatal periods. In this article, we review the literature pertaining to anxiety and anxiety-related disorders during the perinatal period. We also provide information related to pregnancy-specific anxiety and fear of childbirth constructs that exist outside of diagnostic classification but are particularly important in the perinatal context. We review the scope, prevalence, and etiology of these disorders as well as comorbidity, screening, assessment, and treatment. We conclude with an overview of some of the key gaps in knowledge and recommendations for future research.