Task-order coordination in dual-task performance and the lateral prefrontal cortex: an event-related fMRI study

A crucial demand in dual tasks suffering from a capacity limited processing mechanism is task-order scheduling, i.e. the control of the order in which the two component tasks are processed by this limited processing mechanism. The present study aims to test whether the lateral prefrontal cortex (LPFC) is associated with this demand. For this, 15 participants performed a psychological refractory paradigm (PRP) type dual task in an event-related functional magnetic resonance (fMRI) experiment. In detail, two choice reaction tasks, a visual (response with right hand) and an auditory (response with left hand), were presented with a temporal offset of 200 ms, while the participants were required to respond to the tasks in the order of their presentation. Importantly, the presentation order of the tasks changed randomly. Based on previous evidence, we argue that trials in which the present task order changed as compared to the previous trial (different-order trials) impose higher demands on task coordination than same-order trials do. The analyses showed that cortical areas along the posterior part of the left inferior frontal sulcus as well as the right posterior middle frontal gyrus were more strongly activated in different-order than in same-order trials, thus supporting the conclusion that one function of the LPFC for dual-task performance is the temporal coordination of two tasks. Furthermore, it is discussed that the present findings favour the active scheduling over the passive queuing hypothesis of dual-task processing

Cognitive load, working memory capacity and driving performance: A preliminary fNIRS and eye tracking study

Data availability: Data will be made available on request.Copyright © 2022 The Author(s). Published by Elsevier Ltd. A common cause of road traffic incidents is driver distraction, which can occur when the driver’s attention is engaged in a concurrent secondary task. However, the relationship between cognitive demands, individual differences in working memory capacity and driving performance has received little research attention. Using a fixed-base driving simulator, the aim of this study was to use a combination of self-report, functional near infrared spectroscopy (fNIRS) and mobile eye tracking data to investigate the impact of cognitive load on drivers’ gaze behaviour and driving performance, as well as explore the relationship between working memory capacity and driving performance under increased cognitive load. Twenty-one participants with a range of driving experiences (e.g., 0–14 h per week) completed a simulated driving task in a simple environment (i.e., country highway) under single-task (driving only) and dual-task (driving + modified 2-back task) conditions. Cognitive load was assessed via fNIRS data that manifested as changes in regional oxygen saturation (rSO2) in prefrontal cortex as well as self-report data of perceived mental effort. Participants’ working memory capacity was assessed using the Operation Span Task. Findings showed that prefrontal rSO2 and perceived mental effort was significantly greater under dual-task conditions compared to the single-task condition. In the dual-task condition, participants’ gaze dwelled for longer on the road and they made fewer fixations, of longer durations. Participants were able to maintain driving performance in this condition, although this was at the expense of secondary task performance. Interestingly, driving infractions under dual-task conditions were negatively correlated with participants’ working memory capacity. The findings suggest that engaging with distracting secondary tasks while driving may increase drivers’ cognitive load and change their gaze behaviour. Driving performance can seemingly be maintained under such conditions, but this may be partly determined by the driver’s working memory capacity

What do we teach when we teach the Learning Sciences? A document analysis of 75 graduate programs

The learning sciences, as an academic community investigating human learning, emerged more than 30 years ago. Since then, graduate learning sciences programs have been established worldwide. Little is currently known, however, about their disciplinary backgrounds and the topics and research methods they address. In this document analysis of the websites of 75 international graduate learning sciences programs, we examine central concepts and research methods across institutions, compare the programs, and assess the homogeneity of different subgroups. Results reveal that the concepts addressed most frequently were real-world learning in formal and informal contexts, designing learning environments, cognition and metacognition, and using technology to support learning. Among research methods, design-based research (DBR), discourse and dialog analyses, and basic statistics stand out. Results show substantial differences between programs, yet programs focusing on DBR show the greatest similarity regarding the other concepts and methods they teach. Interpreting the similarity of the graduate programs using a community of practice perspective, there is a set of relatively coherent programs at the core of the learning sciences, pointing to the emergence of a discipline, and a variety of multidisciplinary and more heterogeneous programs “orbiting” the core in the periphery, shaping and innovating the field

Competing Neural Responses for Auditory and Visual Decisions

Why is it hard to divide attention between dissimilar activities, such as reading and listening to a conversation? We used functional magnetic resonance imaging (fMRI) to study interference between simple auditory and visual decisions, independently of motor competition. Overlapping activity for auditory and visual tasks performed in isolation was found in lateral prefrontal regions, middle temporal cortex and parietal cortex. When the visual stimulus occurred during the processing of the tone, its activation in prefrontal and middle temporal cortex was suppressed. Additionally, reduced activity was seen in modality-specific visual cortex. These results paralleled impaired awareness of the visual event. Even without competing motor responses, a simple auditory decision interferes with visual processing on different neural levels, including prefrontal cortex, middle temporal cortex and visual regions

Measurement of the charged-pion polarisability

The COMPASS collaboration at CERN has investigated pion Compton scattering, $\pi^-\gamma\rightarrow \pi^-\gamma$, at centre-of-mass energy below 3.5 pion masses. The process is embedded in the reaction $\pi^-\mathrm{Ni}\rightarrow\pi^-\gamma\;\mathrm{Ni}$, which is initiated by 190\,GeV pions impinging on a nickel target. The exchange of quasi-real photons is selected by isolating the sharp Coulomb peak observed at smallest momentum transfers, $Q^2<0.0015$\,(GeV/$c$)$^2$. From a sample of 63\,000 events the pion electric polarisability is determined to be $\alpha_\pi\ =\ (\,2.0\ \pm\ 0.6_{\mbox{\scriptsize stat}}\ \pm\ 0.7_{\mbox{\scriptsize syst}}\,) \times 10^{-4}\,\mbox{fm}^3$under the assumption$\alpha_\pi=-\beta_\pi$, which relates the electric and magnetic dipole polarisabilities. It is the most precise measurement of this fundamental low-energy parameter of strong interaction, that has been addressed since long by various methods with conflicting outcomes. While this result is in tension with previous dedicated measurements, it is found in agreement with the expectation from chiral perturbation theory. An additional measurement replacing pions by muons, for which the cross-section behavior is unambigiously known, was performed for an independent estimate of the systematic uncertainty.Comment: Published version: 9 pages, 3 figures, 1 tabl

Comparison of embedded and added motor imagery training in patients after stroke: Study protocol of a randomised controlled pilot trial using a mixed methods approach

Copyright @ 2009 Schuster et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Background: Two different approaches have been adopted when applying motor imagery (MI) to stroke patients. MI can be conducted either added to conventional physiotherapy or integrated within therapy sessions. The proposed study aims to compare the efficacy of embedded MI to an added MI intervention. Evidence from pilot studies reported in the literature suggests that both approaches can improve performance of a complex motor skill involving whole body movements, however, it remains to be demonstrated, which is the more effective one.Methods/Design: A single blinded, randomised controlled trial (RCT) with a pre-post intervention design will be carried out. The study design includes two experimental groups and a control group (CG). Both experimental groups (EG1, EG2) will receive physical practice of a clinical relevant motor task ('Going down, laying on the floor, and getting up again') over a two week intervention period: EG1 with embedded MI training, EG2 with MI training added after physiotherapy. The CG will receive standard physiotherapy intervention and an additional control intervention not related to MI.The primary study outcome is the time difference to perform the task from pre to post-intervention. Secondary outcomes include level of help needed, stages of motor task completion, degree of motor impairment, balance ability, fear of falling measure, motivation score, and motor imagery ability score. Four data collection points are proposed: twice during baseline phase, once following the intervention period, and once after a two week follow up. A nested qualitative part should add an important insight into patients' experience and attitudes towards MI. Semi-structured interviews of six to ten patients, who participate in the RCT, will be conducted to investigate patients' previous experience with MI and their expectations towards the MI intervention in the study. Patients will be interviewed prior and after the intervention period.Discussion: Results will determine whether embedded MI is superior to added MI. Findings of the semi-structured interviews will help to integrate patient's expectations of MI interventions in the design of research studies to improve practical applicability using MI as an adjunct therapy technique

Spin alignment and violation of the OZI rule in exclusive ω\omega and ϕ\phi production in pp collisions

Exclusive production of the isoscalar vector mesons $\omega$ and $\phi$ is measured with a 190 GeV$/c$ proton beam impinging on a liquid hydrogen target. Cross section ratios are determined in three intervals of the Feynman variable $x_{F}$ of the fast proton. A significant violation of the OZI rule is found, confirming earlier findings. Its kinematic dependence on $x_{F}$ and on the invariant mass $M_{p\mathrm{V}}$ of the system formed by fast proton $p_\mathrm{fast}$ and vector meson $V$ is discussed in terms of diffractive production of $p_\mathrm{fast}V$ resonances in competition with central production. The measurement of the spin density matrix element $\rho_{00}$ of the vector mesons in different selected reference frames provides another handle to distinguish the contributions of these two major reaction types. Again, dependences of the alignment on $x_{F}$ and on $M_{p\mathrm{V}}$ are found. Most of the observations can be traced back to the existence of several excited baryon states contributing to $\omega$ production which are absent in the case of the $\phi$ meson. Removing the low-mass $M_{p\mathrm{V}}$ resonant region, the OZI rule is found to be violated by a factor of eight, independently of $x_\mathrm{F}$.Comment: 23 pages, 13 figures and 5 table

Collins and Sivers asymmetries in muonproduction of pions and kaons off transversely polarised proton

Measurements of the Collins and Sivers asymmetries for charged pions and charged and neutral kaons produced in semi-inclusive deep-inelastic scattering of high energy muons off transversely polarised protons are presented. The results were obtained using all the available COMPASS proton data, which were taken in the years 2007 and 2010. The Collins asymmetries exhibit in the valence region a non-zero signal for pions and there are hints of non-zero signal also for kaons. The Sivers asymmetries are found to be positive for positive pions and kaons and compatible with zero otherwise.Comment: 15 pages, 13 figures and 1 tabl

Search for exclusive photoproduction of Zc±_c^{\pm}(3900) at COMPASS

A search for the exclusive production of the $Z_c^{\pm}(3900)$ hadron by virtual photons has been performed in the channel $Z_c^{\pm}(3900)\rightarrow J/\psi \pi^{\pm}$. The data cover the range from 7 GeV to 19 GeV in the centre-of-mass energy of the photon-nucleon system. The full set of the COMPASS data set collected with a muon beam between 2002 and 2011 has been used. An upper limit for the ratio $BR(Z_c^{\pm}(3900)\rightarrow J/\psi \pi^{\pm} )\times \sigma_{ \gamma~N \rightarrow Z_c^{\pm}(3900)~ N} /\sigma_{\gamma~N \rightarrow J/\psi~ N}$ of $3.7\times10^{-3}$ has been established at the confidence level of 90%.Comment: 8 pages, 3 figures, 1 tabl

The Spin Structure Function g1pg_1^{\rm p} of the Proton and a Test of the Bjorken Sum Rule

New results for the double spin asymmetry $A_1^{\rm p}$ and the proton longitudinal spin structure function $g_1^{\rm p}$ are presented. They were obtained by the COMPASS collaboration using polarised 200 GeV muons scattered off a longitudinally polarised NH$_3$ target. The data were collected in 2011 and complement those recorded in 2007 at 160\,GeV, in particular at lower values of $x$. They improve the statistical precision of $g_1^{\rm p}(x)$ by about a factor of two in the region $x\lesssim 0.02$. A next-to-leading order QCD fit to the $g_1$ world data is performed. It leads to a new determination of the quark spin contribution to the nucleon spin, $\Delta \Sigma$ ranging from 0.26 to 0.36, and to a re-evaluation of the first moment of $g_1^{\rm p}$. The uncertainty of $\Delta \Sigma$ is mostly due to the large uncertainty in the present determinations of the gluon helicity distribution. A new evaluation of the Bjorken sum rule based on the COMPASS results for the non-singlet structure function $g_1^{\rm NS}(x,Q^2)$ yields as ratio of the axial and vector coupling constants $|g_{\rm A}/g_{\rm V}| = 1.22 \pm 0.05~({\rm stat.}) \pm 0.10~({\rm syst.})$, which validates the sum rule to an accuracy of about 9\%.Comment: 19 pages, 8 figures and table