23 research outputs found

    Filling the void - enriching the feature space of successful stopping

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    The ability to inhibit behavior is crucial for adaptation in a fast changing environment and is commonly studied with the stop signal task. Current EEG research mainly focuses on the N200 and P300 ERPs and corresponding activity in the theta and delta frequency range, thereby leaving us with a limited understanding of the mechanisms of response inhibition. Here, 15 functional networks were estimated from time-frequency transformed EEG recorded during processing of a visual stop signal task. Cortical sources underlying these functional networks were reconstructed, and a total of 45 features, each representing spectrally and temporally coherent activity, were extracted to train a classifier to differentiate between go and stop trials. A classification accuracy of 85.55% for go and 83.85% for stop trials was achieved. Features capturing fronto-central delta- and theta activity, parieto-occipital alpha, fronto-central as well as right frontal beta activity were highly discriminating between trial-types. However, only a single network, comprising a feature defined by oscillatory activity below 12 Hz, was associated with a generator in the opercular region of the right inferior frontal cortex and showed the expected associations with behavioral inhibition performance. This study pioneers by providing a detailed ranking of neural features regarding their information content for stop and go differentiation at the single-trial level, and may further be the first to identify a scalp EEG marker of the inhibitory control network. This analysis allows for the characterization of the temporal dynamics of response inhibition by matching electrophysiological phenomena to cortical generators and behavioral inhibition performanc

    Molnupiravir Plus Usual Care Versus Usual Care Alone as Early Treatment for Adults with COVID-19 at Increased Risk of Adverse Outcomes (PANORAMIC): Preliminary Analysis from the United Kingdom Randomised, Controlled Open-Label, Platform Adaptive Trial

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    Background: The safety, effectiveness and cost-effectiveness of molnupiravir, an oral antiviral medication for SARS-CoV-2, in patients in the community who are multiply-vaccinated and at increased risk of morbidity and mortality from COVID-19, has not been established. We aimed to determine whether molnupiravir added to usual care reduced hospital admissions/deaths among people at higher risk from COVID-19, and here report our preliminary analyses. Methods: Participants in this UK multicentre, open-label, adaptive, multi-arm, platform, randomised controlled trial were aged ≥50, or ≥18 years with comorbidities, and unwell ≤5 days with confirmed COVID-19 in the community, and were randomised to usual care or usual care plus molnupiravir (800mg twice daily for 5 days). The primary outcome measure was all-cause hospitalisation/death within 28 days, analysed using Bayesian models. The main secondary outcome measure was time to first self-reported recovery. A sub-set of participants in each group were assessed for the virology primary outcome measure of day seven SARS-CoV-2 viral load. Trial registration: ISRCTN30448031 Findings: Between December 8, 2021 and April 27, 2022, 25783 participants were randomised to molnupiravir plus usual care (n=12821) or usual care alone (n=12962). Mean (range) age of participants was 56·6 years (18 to 99), 58·6% were female, and 99% had at least one dose of a SARS-CoV-2 vaccine. The median duration of symptoms prior to randomisation was two days (IQR 1 – 3), the median number of days from symptom onset to starting to take the medication was three days (IQR 3 – 4), 87% (11109/11997) received their medication within five days of symptom onset, and 95·4% (n=11857) of participants randomised to molnupiravir reported taking molnupiravir for five days. Primary outcome measure data were available in 25000 (97%) participants and included in this analysis. 103/12516 (0·8%) hospitalisations/deaths occurred in the molnupiravir group versus 96/12484 (0·8%) in usual care alone with a posterior probability of superiority of 0·34 (adjusted odds ratio 1·061 (95% Bayesian credible interval [BCI]) 0·80 to 1·40). Estimates were similar for all subgroups. The observed median (IQR) time-to-first-recovery from randomisation was 9 (5–23) days in molnupiravir and 15 (7–not reached) days in usual care. There was an estimated benefit of 4·2 (95% BCI: 3·8 – 4·6) days in time-to-first-recovery (TTR) giving a posterior probability of superiority of >0·999 (estimated median TTR 10·3 [10·2 – 10·6] days vs 14·5 [14·2 – 14·9] days respectively; hazard ratio [95% BCI], 1·36 [1·3–1·4] days), which met the pre-specified superiority threshold. On day 7, SARS-CoV-2 virus was below detection levels in 7/34 (21%) of the molnupiravir group, versus 1/39 (3%) in the usual care group (p=0.039), and mean viral load was lower in the molnupiravir group compared with those receiving usual care [(SD) of log10(viral load) 3·82 (1·40) in the molnupiravir group and 4.93 (1·38) in the usual care group, (P<0·001)]. 59 (0·4%) participants experienced serious adverse events in the molnupiravir group and 52 (0·4%) in usual care. Interpretation: In this preliminary analysis, we found that molnupiravir did not reduce already low hospitalisations/deaths among higher risk, vaccinated adults with COVID-19 in the community, but resulted in faster time to recovery, and reduced viral detection and load. Funding: This project is funded by the NIHR (NIHR135366). The views expressed are those of the authors and not necessarily those of the NIHR or the Department of Health and Social Care

    Molnupiravir plus usual care versus usual care alone as early treatment for adults with COVID-19 at increased risk of adverse outcomes (PANORAMIC): an open-label, platform-adaptive randomised controlled trial

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    Background: The safety, effectiveness, and cost-effectiveness of molnupiravir, an oral antiviral medication for SARS-CoV-2, has not been established in vaccinated patients in the community at increased risk of morbidity and mortality from COVID-19. We aimed to establish whether the addition of molnupiravir to usual care reduced hospital admissions and deaths associated with COVID-19 in this population. Methods: PANORAMIC was a UK-based, national, multicentre, open-label, multigroup, prospective, platform adaptive randomised controlled trial. Eligible participants were aged 50 years or older—or aged 18 years or older with relevant comorbidities—and had been unwell with confirmed COVID-19 for 5 days or fewer in the community. Participants were randomly assigned (1:1) to receive 800 mg molnupiravir twice daily for 5 days plus usual care or usual care only. A secure, web-based system (Spinnaker) was used for randomisation, which was stratified by age (&lt;50 years vs ≥50 years) and vaccination status (yes vs no). COVID-19 outcomes were tracked via a self-completed online daily diary for 28 days after randomisation. The primary outcome was all-cause hospitalisation or death within 28 days of randomisation, which was analysed using Bayesian models in all eligible participants who were randomly assigned. This trial is registered with ISRCTN, number 30448031. Findings: Between Dec 8, 2021, and April 27, 2022, 26 411 participants were randomly assigned, 12 821 to molnupiravir plus usual care, 12 962 to usual care alone, and 628 to other treatment groups (which will be reported separately). 12 529 participants from the molnupiravir plus usual care group, and 12 525 from the usual care group were included in the primary analysis population. The mean age of the population was 56·6 years (SD 12·6), and 24 290 (94%) of 25 708 participants had had at least three doses of a SARS-CoV-2 vaccine. Hospitalisations or deaths were recorded in 105 (1%) of 12 529 participants in the molnupiravir plus usual care group versus 98 (1%) of 12 525 in the usual care group (adjusted odds ratio 1·06 [95% Bayesian credible interval 0·81–1·41]; probability of superiority 0·33). There was no evidence of treatment interaction between subgroups. Serious adverse events were recorded for 50 (0·4%) of 12 774 participants in the molnupiravir plus usual care group and for 45 (0·3%) of 12 934 in the usual care group. None of these events were judged to be related to molnupiravir. Interpretation: Molnupiravir did not reduce the frequency of COVID-19-associated hospitalisations or death among high-risk vaccinated adults in the community

    Molnupiravir plus usual care versus usual care alone as early treatment for adults with COVID-19 at increased risk of adverse outcomes (PANORAMIC): an open-label, platform-adaptive randomised controlled trial

    Get PDF
    BackgroundThe safety, effectiveness, and cost-effectiveness of molnupiravir, an oral antiviral medication for SARS-CoV-2, has not been established in vaccinated patients in the community at increased risk of morbidity and mortality from COVID-19. We aimed to establish whether the addition of molnupiravir to usual care reduced hospital admissions and deaths associated with COVID-19 in this population.MethodsPANORAMIC was a UK-based, national, multicentre, open-label, multigroup, prospective, platform adaptive randomised controlled trial. Eligible participants were aged 50 years or older—or aged 18 years or older with relevant comorbidities—and had been unwell with confirmed COVID-19 for 5 days or fewer in the community. Participants were randomly assigned (1:1) to receive 800 mg molnupiravir twice daily for 5 days plus usual care or usual care only. A secure, web-based system (Spinnaker) was used for randomisation, which was stratified by age (<50 years vs ≥50 years) and vaccination status (yes vs no). COVID-19 outcomes were tracked via a self-completed online daily diary for 28 days after randomisation. The primary outcome was all-cause hospitalisation or death within 28 days of randomisation, which was analysed using Bayesian models in all eligible participants who were randomly assigned. This trial is registered with ISRCTN, number 30448031.FindingsBetween Dec 8, 2021, and April 27, 2022, 26 411 participants were randomly assigned, 12 821 to molnupiravir plus usual care, 12 962 to usual care alone, and 628 to other treatment groups (which will be reported separately). 12 529 participants from the molnupiravir plus usual care group, and 12 525 from the usual care group were included in the primary analysis population. The mean age of the population was 56·6 years (SD 12·6), and 24 290 (94%) of 25 708 participants had had at least three doses of a SARS-CoV-2 vaccine. Hospitalisations or deaths were recorded in 105 (1%) of 12 529 participants in the molnupiravir plus usual care group versus 98 (1%) of 12 525 in the usual care group (adjusted odds ratio 1·06 [95% Bayesian credible interval 0·81–1·41]; probability of superiority 0·33). There was no evidence of treatment interaction between subgroups. Serious adverse events were recorded for 50 (0·4%) of 12 774 participants in the molnupiravir plus usual care group and for 45 (0·3%) of 12 934 in the usual care group. None of these events were judged to be related to molnupiravir.InterpretationMolnupiravir did not reduce the frequency of COVID-19-associated hospitalisations or death among high-risk vaccinated adults in the community

    Stimulus-Response Mappings Shape Inhibition Processes: A Combined EEG-fMRI Study of Contextual Stopping

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    <div><p>Humans are rarely faced with one simple task, but are typically confronted with complex stimulus constellations and varying stimulus-relevance in a given situation. Through modifying the prototypical stop-signal task and by combined recording and analysis of electroencephalography (EEG) and functional magnetic resonance imaging (fMRI), we studied the effects of stimulus relevance for the generation of a response or its inhibition. Stimulus response mappings were modified by contextual cues, indicating which of two different stimuli following a go stimulus was relevant for stopping. Overall, response inhibition, that is comparing successful stopping to a stop-signal against go-signal related processes, was associated with increased activity in right inferior and left midfrontal regions, as well as increased EEG delta and theta power; however, stimulus-response conditions in which the most infrequent stop-signal was relevant for inhibition, were associated with decreased activity in regions typically involved in response inhibition, as well as decreased activity in the delta and theta bands as compared to conditions wherein the relevant stop-signal frequency was higher. Behaviorally, this (aforementioned) condition, which demanded inhibition only from the most infrequent stimulus, was also associated with reduced reaction times and lower error rates. This pattern of results does not align with typical stimulus frequency-driven findings and suggests interplay between task relevance and stimulus frequency of the stop-signal. Moreover, with a multimodal EEG-fMRI analysis, we demonstrated significant parameterization for response inhibition with delta, theta and beta time-frequency values, which may be interpreted as reflecting conflict monitoring, evaluative and/or motor processes as suggested by previous work (Huster et al., 2013; Aron, 2011). Further multimodal results suggest a possible neurophysiological and behavioral benefit under conditions whereby the most infrequent stimulus demanded inhibition, indicating that the frequency of the stop-signal interacts with the current stimulus-response contingency. These results demonstrate that response inhibition is prone to influence from other cognitive functions, making it difficult to dissociate real inhibitory capabilities from the influence of moderating mechanisms.</p></div

    EEG-informed fMRI Results.

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    <p>Results from time-frequency EEG-informed fMRI analyses reveal overlapping effects across frequency bands for response inhibition, especially within the left MFG and to a lesser extent the right inferior frontal region and cingulate gyrus; however, theta band parameterization additionally reveals larger activation within the superior frontal gyrus. T-values are reported in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0096159#pone-0096159-t003" target="_blank">Tables 3</a>–<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0096159#pone-0096159-t005" target="_blank">5</a>, along with voxel data and MNI co-ordinates.</p

    Unimodal fMRI Results.

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    <p>Results from the unimodal fMRI analysis reveal increased activity in the rIFG and left MFG during response inhibition (Stim1> Go) and decreased activity in the rIFG under stimulus-response scenarios in which the most infrequent stimuli demanded inhibition (Stim1-Context1> Stim1-Context2). T-values are reported in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0096159#pone-0096159-t002" target="_blank">Table 2</a>, along with voxel data and MNI co-ordinates.</p

    Time-frequency plots.

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    <p>The time-frequency plots for Go, Stim1 and Stim2 for context1 from electrode FCz are displayed in power (dB) from 400 ms prior to stimulus onset (0) to 800 ms post-stimulus onset. The temporal windows and associated time-frequency bands δ = delta, θ = theta, β1 = low beta, β2 =  high beta) are illustrated directly on the plots.</p
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