518 research outputs found
The role of the insula in speech and language processing
Lesion and neuroimaging studies indicate that the insula mediates motor aspects of speech production, specifically, articulatory control. Although it has direct connections to Broca\u27s area, the canonical speech production region, the insula is also broadly connected with other speech and language centres, and may play a role in coordinating higher-order cognitive aspects of speech and language production. The extent of the insula\u27s involvement in speech and language processing was assessed using the Activation Likelihood Estimation (ALE) method. Meta-analyses of 42 fMRI studies with healthy adults were performed, comparing insula activation during performance of language (expressive and receptive) and speech (production and perception) tasks. Both tasks activated bilateral anterior insulae. However, speech perception tasks preferentially activated the left dorsal mid-insula, whereas expressive language tasks activated left ventral mid-insula. Results suggest distinct regions of the mid-insula play different roles in speech and language processing. © 2014 Elsevier Inc
Theta-Modulated Gamma-Band Synchronization Among Activated Regions During a Verb Generation Task
Expressive language is complex and involves processing within a distributed network of cortical regions. Functional MRI and magnetoencephalography (MEG) have identified brain areas critical for expressive language, but how these regions communicate across the network remains poorly understood. It is thought that synchronization of oscillations between neural populations, particularly at a gamma rate (>30 Hz), underlies functional integration within cortical networks. Modulation of gamma rhythms by theta-band oscillations (4–8 Hz) has been proposed as a mechanism for the integration of local cell coalitions into large-scale networks underlying cognition and perception. The present study tested the hypothesis that these oscillatory mechanisms of functional integration were present within the expressive language network. We recorded MEG while subjects performed a covert verb generation task. We localized activated cortical regions using beamformer analysis, calculated inter-regional phase locking between activated areas, and measured modulation of inter-regional gamma synchronization by theta phase. The results show task-dependent gamma-band synchronization among regions activated during the performance of the verb generation task, and we provide evidence that these transient and periodic instances of high-frequency connectivity were modulated by the phase of cortical theta oscillations. These findings suggest that oscillatory synchronization and cross-frequency interactions are mechanisms for functional integration among distributed brain areas supporting expressive language processing
Cognitive optimism of distinctive initiatives to foster self-directed and self-regulated learning skills:A comparative analysis of conventional and blended-learning in undergraduate studies
Independent learning in massive open online courses (MOOCs) requires considerable effort from the learners themselves. Blended-learning has been recognised to foster independent learning among undergraduate students. With the popularity of the blended-learning approach to teach in traditional educational settings, little has been mentioned on how cohesive this approach is in fostering self-directed learning and self-regulation among university students. This study hopes to explore undergraduate learners in their distinctive study patterns. The study was conducted to investigate a comparative study between students from two departments; Science and Social Science. The aim was to explore the students’ self-directed and self-regulated learning skills in conventional classrooms and aspects of blended-learning embedded in a MOOC platform in two academic years for undergraduates at a top UK university. This study encompasses two case studies; firstly, a combine blended-learning seminar and a conventional seminar classes and a study undertaken with a student of English as a second language (ESL). The blended-learning students were participants who registered in a conventional university and took an optional module in computer security. The second group of students participated in a core module of logic and verification. The second case study was with a final year undergraduate student in Education Studies. The students studied and engaged with the course content using their initiative and directing their learning approaches
Validity of self-reported smoking status: comparison of patients admitted to hospital with acute coronary syndrome and the general population
Many studies rely on self-reported smoking status. We hypothesized that patients with acute coronary syndrome (ACS), a smoking-related condition, would be more prone to misclassify themselves as ex-smokers, because of pressure to quit. We compared patients admitted with ACS with a general population survey conducted in the same country at a similar time. We determined whether ACS patients who classified themselves as ex-smokers (n = 635) were more likely to have cotinine levels suggestive of smoking deception than self-reported ex-smokers in the general population (n = 289). On univariate analysis, the percentage of smoking deceivers was similar among ACS patients and the general population (11% vs. 12%, p = .530). Following adjustment for age, sex and exposure to environmental tobacco smoke, ACS patients were significantly more likely to misclassify themselves (adjusted OR = 14.06, 95% CI 2.13-93.01, p = .006). There was an interaction with age whereby the probability of misclassification fell significantly with increasing age in the ACS group (adjusted OR = 0.95, 95% CI 0.93-0.97, p<.001), but not in the general population. Overall, smoking deception was more common among ACS patients than the general population. Studies comparing patients with cardiovascular disease and healthy individuals risk introducing bias if they rely solely on self-reported smoking status. Biochemical confirmation should be undertaken in such studies
Mobile integrated health to reduce post-discharge acute care visits: A pilot study
Background
Mobile Integrated Health (MIH) leverages specially trained paramedics outside of emergency response to bridge gaps in local health care delivery.
Study objective
To evaluate the efficacy of a MIH led transitional care strategy to reduce acute care utilization.
Methods
This was a retrospective cohort analysis of a quality improvement pilot of patient patients from an urban, single county EMS, MIH transitional care initiative. We utilized a paramedic/social worker (or social care coordinator) dyad to provide in home assessments, medication review, care coordination, and improve access to care. The primary outcome compared acute care utilization (ED visits, observation stays, inpatient visits) 90 days before MIH intervention to 90 days after.
Results
Of the 203 patients seen by MIH teams, inpatient utilization decreased significantly from 140 hospitalizations pre-MIH to 26 post-MIH (83% reduction, p = 0.00). ED and observation stays, however, increased numerically, but neither was significant. (ED 18 to 19 stays, p = 0.98; observation stays 95 to 106, p = 0.30) Primary care visits increased 15% (p = 0.11).
Conclusion
In this pilot before/after study, MIH significantly reduces acute care hospitalizations
Is inhibitory control a ‘no-go’ in adolescents with autism spectrum disorder?
BACKGROUND: Autism spectrum disorder (ASD) refers to a range of neurodevelopmental conditions characterized by social communication deficits, repetitive behaviours, and restrictive interests. Impaired inhibition has been suggested to exacerbate the core symptoms of ASD. This is particularly critical during adolescence when social skills are maturing to adult levels. Using magnetoencephalography (MEG), we identified the location and timing pattern of neural activity associated with inhibition in adolescents with autism, compared to typically developing adolescents. METHODS: The MEG data from 15 adolescents with ASD and 15 age-matched controls (13 to 17 years) were collected during a go/no-go task with inverse ratios of go/no-go trials in two conditions: an inhibition condition (1:2) and a baseline condition (2:1). No-go trials from the two conditions were analyzed using beamformer source localizations from 200 ms to 400 ms post-stimulus onset. Significant activations were determined using permutation testing. RESULTS: Adolescents with ASD recruited first the right middle frontal gyrus (200 to 250 ms) followed by the left postcentral gyrus (250 to 300 ms) and finally the left middle frontal and right medial frontal gyri (300 to 400 ms). Typically developing adolescents recruited first the left middle frontal gyrus (200 to 250 ms), followed by the left superior and inferior frontal gyri (250 to 300 ms), then the right middle temporal gyrus (300 to 350 ms), and finally the superior and precentral gyri and right inferior lobule (300 to 400 ms). CONCLUSIONS: Adolescents with ASD showed recruitment limited largely to the frontal cortex unlike typically developing adolescents who recruited parietal and temporal regions as well. These findings support the presence of an atypical, restricted inhibitory network in adolescents with ASD compared to controls
Leveraging Rationales to Improve Human Task Performance
Machine learning (ML) systems across many application areas are increasingly
demonstrating performance that is beyond that of humans. In response to the
proliferation of such models, the field of Explainable AI (XAI) has sought to
develop techniques that enhance the transparency and interpretability of
machine learning methods. In this work, we consider a question not previously
explored within the XAI and ML communities: Given a computational system whose
performance exceeds that of its human user, can explainable AI capabilities be
leveraged to improve the performance of the human? We study this question in
the context of the game of Chess, for which computational game engines that
surpass the performance of the average player are widely available. We
introduce the Rationale-Generating Algorithm, an automated technique for
generating rationales for utility-based computational methods, which we
evaluate with a multi-day user study against two baselines. The results show
that our approach produces rationales that lead to statistically significant
improvement in human task performance, demonstrating that rationales
automatically generated from an AI's internal task model can be used not only
to explain what the system is doing, but also to instruct the user and
ultimately improve their task performance.Comment: ACM IUI 202
N-Terminal Pro–B-Type Natriuretic Peptide in the Emergency Department: The ICON-RELOADED Study
Background
Contemporary reconsideration of diagnostic N-terminal pro–B-type natriuretic peptide (NT-proBNP) cutoffs for diagnosis of heart failure (HF) is needed.
Objectives
This study sought to evaluate the diagnostic performance of NT-proBNP for acute HF in patients with dyspnea in the emergency department (ED) setting.
Methods
Dyspneic patients presenting to 19 EDs in North America were enrolled and had blood drawn for subsequent NT-proBNP measurement. Primary endpoints were positive predictive values of age-stratified cutoffs (450, 900, and 1,800 pg/ml) for diagnosis of acute HF and negative predictive value of the rule-out cutoff to exclude acute HF. Secondary endpoints included sensitivity, specificity, and positive (+) and negative (−) likelihood ratios (LRs) for acute HF.
Results
Of 1,461 subjects, 277 (19%) were adjudicated as having acute HF. The area under the receiver-operating characteristic curve for diagnosis of acute HF was 0.91 (95% confidence interval [CI]: 0.90 to 0.93; p < 0.001). Sensitivity for age stratified cutoffs of 450, 900, and 1,800 pg/ml was 85.7%, 79.3%, and 75.9%, respectively; specificity was 93.9%, 84.0%, and 75.0%, respectively. Positive predictive values were 53.6%, 58.4%, and 62.0%, respectively. Overall LR+ across age-dependent cutoffs was 5.99 (95% CI: 5.05 to 6.93); individual LR+ for age-dependent cutoffs was 14.08, 4.95, and 3.03, respectively. The sensitivity and negative predictive value for the rule-out cutoff of 300 pg/ml were 93.9% and 98.0%, respectively; LR− was 0.09 (95% CI: 0.05 to 0.13).
Conclusions
In acutely dyspneic patients seen in the ED setting, age-stratified NT-proBNP cutpoints may aid in the diagnosis of acute HF. An NT-proBNP <300 pg/ml strongly excludes the presence of acute HF
The Global Lake Ecological Observatory Network (GLEON): the evolution of grassroots network science
Nine years later, with over 380 members from 40 countries, and 50 publications to its credit, GLEON is growing at a rapid pace and pushing the boundaries of the practice of network science. GLEON is really three networks: a network of lakes, data, and peopl
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