Spatio-temporal judgements of observed actions : Contrasts between first- and third-person perspective after motor priming.

When observing actions, motor simulation processes aid the prediction and understanding of future events. A central issue concerns whether such action simulation serves social functions of interpreting other people, where performance is predicted to be better when third-person perspective (3PP) actions are viewed; or whether it is most beneficial to guide self actions, whereby the first-person perspective (1PP) would be advantageous. We show that in a spatio-temporal judgement task there is an advantage for the prediction of 1PP. However, this is only detected after motor priming whereby participants perform the observed actions prior to making spatio-temporal judgements. The results, firstly, confirm that we draw on our motor experience for the accurate simulation and prediction of action. Secondly, the results suggest that such experience facilitates more accurate state estimation for actions perceived in the 1PP which map more closely onto visual input of self-generated action. More forward prediction error is retained for 3PP viewed actions, which may however have the benefit of compensating for the uncertainty involved in interacting with others

Temporal Accumulation and Decision Processes in the Duration Bisection Task Revealed by Contingent Negative Variation

The duration bisection paradigm is a classic task used to examine how humans and other animals perceive time. Typically, participants first learn short and long anchor durations and are subsequently asked to classify probe durations as closer to the short or long anchor duration. However, the specific representations of time and the decision rules applied in this task remain the subject of debate. For example, researchers have questioned whether participants actually use representations of the short and long anchor durations in the decision process rather than merely a response threshold that is derived from those anchor durations. Electroencephalographic (EEG) measures, like the contingent negative variation (CNV), can provide information about the perceptual and cognitive processes that occur between the onset of the timing stimulus and the motor response. The CNV has been implicated as an electrophysiological marker of interval timing processes such as temporal accumulation, representation of the target duration, and the decision that the target duration has been attained. We used the CNV to investigate which durations are involved in the bisection categorization decision. The CNV increased in amplitude up to the value of the short anchor, remained at a constant level until about the geometric mean (GM) of the short and long anchors, and then began to resolve. These results suggest that the short anchor and the GM of the short and long anchors are critical target durations used in the bisection categorization decision process. In addition, larger mean N1P2 amplitude differences were associated with larger amplitude CNVs, which may reflect the participant’s precision in initiating timing on each trial across a test session. Overall, the results demonstrate the value of using scalp-recorded EEG to address basic questions about interval timing

Convalescent plasma in patients admitted to hospital with COVID-19 (RECOVERY): a randomised controlled, open-label, platform trial

SummaryBackground Azithromycin has been proposed as a treatment for COVID-19 on the basis of its immunomodulatoryactions. We aimed to evaluate the safety and efficacy of azithromycin in patients admitted to hospital with COVID-19.Methods In this randomised, controlled, open-label, adaptive platform trial (Randomised Evaluation of COVID-19Therapy [RECOVERY]), several possible treatments were compared with usual care in patients admitted to hospitalwith COVID-19 in the UK. The trial is underway at 176 hospitals in the UK. Eligible and consenting patients wererandomly allocated to either usual standard of care alone or usual standard of care plus azithromycin 500 mg once perday by mouth or intravenously for 10 days or until discharge (or allocation to one of the other RECOVERY treatmentgroups). Patients were assigned via web-based simple (unstratified) randomisation with allocation concealment andwere twice as likely to be randomly assigned to usual care than to any of the active treatment groups. Participants andlocal study staff were not masked to the allocated treatment, but all others involved in the trial were masked to theoutcome data during the trial. The primary outcome was 28-day all-cause mortality, assessed in the intention-to-treatpopulation. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936.Findings Between April 7 and Nov 27, 2020, of 16 442 patients enrolled in the RECOVERY trial, 9433 (57%) wereeligible and 7763 were included in the assessment of azithromycin. The mean age of these study participants was65·3 years (SD 15·7) and approximately a third were women (2944 [38%] of 7763). 2582 patients were randomlyallocated to receive azithromycin and 5181 patients were randomly allocated to usual care alone. Overall,561 (22%) patients allocated to azithromycin and 1162 (22%) patients allocated to usual care died within 28 days(rate ratio 0·97, 95% CI 0·87–1·07; p=0·50). No significant difference was seen in duration of hospital stay (median10 days [IQR 5 to >28] vs 11 days [5 to >28]) or the proportion of patients discharged from hospital alive within 28 days(rate ratio 1·04, 95% CI 0·98–1·10; p=0·19). Among those not on invasive mechanical ventilation at baseline, nosignificant difference was seen in the proportion meeting the composite endpoint of invasive mechanical ventilationor death (risk ratio 0·95, 95% CI 0·87–1·03; p=0·24).Interpretation In patients admitted to hospital with COVID-19, azithromycin did not improve survival or otherprespecified clinical outcomes. Azithromycin use in patients admitted to hospital with COVID-19 should be restrictedto patients in whom there is a clear antimicrobial indication

Coronal section (x = 50, y = 72, z = 47) of the significant activation for the Time>Sex contrast.

<p>Functional data are thresholded at <i>p</i><0.05 (<i>t</i>>7.26) corrected for multiple comparisons using FWE and are superimposed as a colour overlay on the average of 152 anatomical scans from different brains (Montreal Neurological Institute). <i>Key</i> A. Right SMA (MNI: x = +4, y = +16, z = +52) and Right pre-SMA (MNI: x = +6, y = +26, z = +48). B. Left Insula (MNI: x = −28, y = +18, z = +4). C. Right Putamen (MNI: x = +30, y = +16, z = 0). D. Right Inferior Frontal Gyrus (pars opercularis) (MNI: x = +50, y = +14, z = +8).</p

Areas of significant activation at the threshold <i>p</i>(FWE) <.05 (cluster-level corrected) for the contrast Time>Sex.

<p>MNI coordinates indicate the peak voxel (<i>t</i>>7.26) within each anatomical region. The final two columns display the Pearson product moment correlation coefficients (<i>r</i>) between both the Bisection Point (BP) and Weber Ratio (WR) and activity in each of the regions identified as more active for the contrast Time>Sex.</p>*<p><i>p</i><.01.</p>**<p>cluster-level <i>p</i>(FWE) <.05.</p><p>Abbreviations: SMA  =  Supplementary Motor Area; IFG  =  Inferior Frontal Gyrus.</p

Scatterplot displaying relationship between mean Bisection Point for each individual and mean individual activation (beta values) for the right inferior frontal gyrus (rIFG) for the contrast Time>Sex.

<p>Scatterplot displaying relationship between mean Bisection Point for each individual and mean individual activation (beta values) for the right inferior frontal gyrus (rIFG) for the contrast Time>Sex.</p