Default mode network connectivity during task execution.

Initially described as task-induced deactivations during goal-directed paradigms of high attentional load, the unresolved functionality of default mode regions has long been assumed to interfere with task performance. However, recent evidence suggests a potential default mode network involvement in fulfilling cognitive demands. We tested this hypothesis in a finger opposition paradigm with task and fixation periods which we compared with an independent resting state scan using functional magnetic resonance imaging and a comprehensive analysis pipeline including activation, functional connectivity, behavioural and graph theoretical assessments. The results indicate task specific changes in the default mode network topography. Behaviourally, we show that increased connectivity of the posterior cingulate cortex with the left superior frontal gyrus predicts faster reaction times. Moreover, interactive and dynamic reconfiguration of the default mode network regions' functional connections illustrates their involvement with the task at hand with higher-level global parallel processing power, yet preserved small-world architecture in comparison with rest. These findings demonstrate that the default mode network does not disengage during this paradigm, but instead may be involved in task relevant processing.The Evelyn Trust (RUAG/018) provided the required funding for this research. Additionally, D Vatansever is funded by the Yousef Jameel Academic Program administered via the Cambridge Commonwealth, European and International Trust; DK Menon is supported by funding from the NIHR Cambridge Biomedical Centre (RCZB/004), and an NIHRSenior Investigator Award (RCZB/014), and EA Stamatakis is funded by the Stephen Erskine Fellowship Queens' College Cambridge. We would also like to thank Sanja Abbott for programming the stimulus delivery, Dr. Guy Williams and Victoria Lupson and the rest of the staff in the Wolfson Brain Imaging Centre (WBIC) at Addenbrooke's Hospital for their assistance in scanning. Last but not least, we thank all the participants for their contribution to this study.This is the final version of the article. It was first available from Elsevier via http://dx.doi.org/10.1016/j.neuroimage.2015.07.05

Human rights-based approaches to mental health: A review of programs

The incidence of human rights violations in mental health care across nations has been described as a “global emergency” and an “unresolved global crisis.” The relationship between mental health and human rights is complex and bidirectional. Human rights violations can negatively impact mental health. Conversely, respecting human rights can improve mental health. This article reviews cases where an explicitly human rights-based approach was used in mental health care settings. Although the included studies did not exhibit a high level of methodological rigor, the qualitative information obtained was considered useful and informative for future studies. All studies reviewed suggest that human-rights based approaches can lead to clinical improvements at relatively low costs. Human rights-based approaches should be utilized for legal and moral reasons, since human rights are fundamental pillars of justice and civilization. The fact that such approaches can contribute to positive therapeutic outcomes and, potentially, cost savings, is additional reason for their implementation. However, the small sample size and lack of controlled, quantitative measures limit the strength of conclusions drawn from included studies. More objective, high quality research is needed to ascertain the true extent of benefits to service users and providers.This is the final version of the article. It first appeared from Harvard University Press

The impact of COVID-19 social isolation on aspects of emotional and social cognition

The present study aimed to examine the impact of COVID-19 social isolation upon aspects of emotional and social cognitive function. We predicted that greater impairments in emotional and social cognition would be observed in people who experienced more disruption to their usual social connectivity during COVID-19 social isolation. Healthy volunteers (N = 92) without prior mental health problems completed assessments online in their own homes during the most stringent period of the first COVID-19 "lockdown" in the UK (March - May 2020). Measures included two questionnaires probing levels of social isolation, anxiety levels, as well as five neuropsychological tasks assessing emotional and social cognition. Reduced positive bias in emotion recognition was related to reduced contact with friends, household size and communication method during social isolation. In addition, reduced positive bias for attention to emotional faces was related to frequency of contact with friends during social isolation. Greater cooperative behaviour in an ultimatum game was associated with more frequent contact with both friends and family during social isolation. The present study provides important insights into the detrimental effects of subjective and objective social isolation upon affective cognitive processes

Cognition as a treatment target in depression

Cognitive dysfunction in depression is associated with poorer clinical outcomes and impaired psychosocial functioning. However, most treatments for depression do not specifically target cognition. Neurocognitive deficits such as memory and concentration problems tend to persist after mood symptoms recover. Improving cognition in depression requires a better understanding of brain systems implicated in depression. A comprehensive approach is warranted for refined methods of assessing and treating cognitive dysfunction in depression

Is objective and accurate cognitive assessment across the menstrual cycle possible? A feasibility study

YesOBJECTIVES: Variation in plasma hormone levels influences the neurobiology of brain regions involved in cognition and emotion processing. Fluctuations in hormone levels across the menstrual cycle could therefore alter cognitive performance and wellbeing; reports have provided conflicting results, however. The aim of this study was to assess whether objective assessment of cognitive performance and self-reported wellbeing during the follicular and luteal phases of the menstrual cycle is feasible and investigate the possible reasons for variation in effects previously reported. METHODS: The Cambridge Neuropsychological Test Automated Battery and Edinburgh Postnatal Depression Scale were used to assess the cognitive performance and wellbeing of 12 women. Data were analysed by self-reported and hormone-estimated phases of the menstrual cycle. RESULTS: Recruitment to the study and assessment of cognition and wellbeing was without issue. Plasma hormone and peptide estimation showed substantial individual variation and suggests inaccuracy in self-reported menstrual phase estimation. CONCLUSION: Objective assessment of cognitive performance and self-assessed wellbeing across the menstrual cycle is feasible. Grouping data by hormonal profile rather by self-reported phase estimation may influence phase-mediated results. Future studies should use plasma hormone and peptide profiles to estimate cycle phase and group data for analyses

Working Memory after Traumatic Brain Injury: The Neural Basis of Improved Performance with Methylphenidate

Traumatic brain injury (TBI) often results in cognitive impairments for patients. The aim of this proof of concept study was to establish the nature of abnormalities, in terms of activity and connectivity, in the working memory network of TBI patients and how these relate to compromised behavioral outcomes. Further, this study examined the neural correlates of working memory improvement following the administration of methylphenidate. We report behavioral, functional and structural MRI data from a group of 15 Healthy Controls (HC) and a group of 15 TBI patients, acquired during the execution of the N-back task. The patients were studied on two occasions after the administration of either placebo or 30 mg of methylphenidate. Between group tests revealed a significant difference in performance when HCs were compared to TBI patients on placebo [F$_{(1, 28)}$ = 4.426, p < 0.05, η$_{p}$$^{2}$ = 0.136]. This difference disappeared when the patients took methylphenidate [F$_{(1, 28)}$ = 3.665, p = 0.66]. Patients in the middle range of baseline performance demonstrated the most benefit from methylphenidate. Changes in the TBI patient activation levels in the Left Cerebellum significantly and positively correlated with changes in performance (r = 0.509, df = 13, p = 0.05). Whole-brain connectivity analysis using the Left Cerebellum as a seed revealed widespread negative interactions between the Left Cerebellum and parietal and frontal cortices as well as subcortical areas. Neither the TBI group on methylphenidate nor the HC group demonstrated any significant negative interactions. Our findings indicate that (a) TBI significantly reduces the levels of activation and connectivity strength between key areas of the working memory network and (b) Methylphenidate improves the cognitive outcomes on a working memory task. Therefore, we conclude that methylphenidate may render the working memory network in a TBI group more consistent with that of an intact working memory network.This work was supported by the Evelyn Trust (grant number 06/20). The Evelyn Trust had no role in the conduct of the research for the preparation of the manuscript. DM is supported by the Neuroscience Theme of the NIHR Cambridge Biomedical Research Centre and NIHR Senior Investigator awards, and by Framework Program 7 funding from the European Commission (TBIcare). ES is funded by the Stephen Erskine Fellowship, Queens' College, University of Cambridge, UK

Angular Default Mode Network Connectivity across Working Memory Load

Initially identified during no-task, baseline conditions, it has now been suggested that the default mode network (DMN) engages during a variety of working memory paradigms through its flexible interactions with other large-scale brain networks. Nevertheless, its contribution to whole-brain connectivity dynamics across increasing working memory load has not been explicitly assessed. The aim of our study was to determine which DMN hubs relate to working memory task performance during an fMRI-based $n$-back paradigm with parametric increases in difficulty. Using a voxel-wise metric, termed the intrinsic connectivity contrast (ICC), we found that the bilateral angular gyri (core DMN hubs) displayed the greatest change in global connectivity across three levels of $n$-back task load. Subsequent seed-based functional connectivity analysis revealed that the angular DMN regions robustly interact with other large-scale brain networks, suggesting a potential involvement in the global integration of information. Further support for this hypothesis comes from the significant correlations we found between angular gyri connectivity and reaction times to correct responses. The implication from our study is that the DMN is actively involved during the n-back task and thus plays an important role related to working memory, with its core angular regions contributing to the changes in global brain connectivity in response to increasing environmental demands.Evelyn Trust (RUAG/018), Yousef Jameel Academic Program, National Institute for Health Research Cambridge Biomedical Centre (RCZB/004), National Institute for Health Research (Senior Investigator Award (RCZB/014)), Queens’ College Cambridge (Stephen Erskine Fellowship