Experimental Evaluations of a Model of Mental Workload

1989 ◽  
Vol 33 (18) ◽  
pp. 1233-1237 ◽  
Author(s):  
P. A. Hancock ◽  
M. H. Chignell ◽  
M. Vercruyssen ◽  
M. Denhoff
Keyword(s):  
Path Length ◽  
Mental Workload ◽  
Movement Time ◽  
A Priori ◽  
Independent Effect ◽  
Subjective Perception ◽  
Performance Task ◽  
Related Factors ◽  
Task Goal ◽  
Systematic Effects

The present experiments were designed to test predictions from a model of mental workload. The model predicts non-linear increases in mental workload as perceived distance from a task goal grows and effective time for action is reduced. Diminution of mental workload is achieved by application of effort which brings the task goal into the region of acceptable time/distance constraints for successful resolution. Two experiments are reported which tested these assertions using the timepools performance task. Timepools is unique as a performance task in that it generates a spatial representation of a shrinking temporal target. The independent effects of path length, i.e., the number of sequential targets to be acquired, and shrink rate, i.e., the collapse time during which the circle is halved in area, may be assessed using performance variables such as reaction time (RT), movement time (MT), error rate (E), and the subjective perception of workload. Data from Experiment 1, indicate systematic effects for task related factors across performance and workload measures, although such a pattern was not isomorphically mapped to the a priori assumed difficulty of the task. In Experiment 2, shrink rate and path length had independent effect on RT and MT respectively, which were reflected in components of the individual workload scales. The ramifications with respect to the model are elaborated.

Estimation of Duration and Mental Workload at Differing Times of Day by Males and Females

1988 ◽  
Vol 32 (14) ◽  
pp. 857-861 ◽  
Author(s):  
P.A. Hancock ◽  
G.J. Rodenburg ◽  
W.D. Mathews ◽  
M. Vercruyssen
Keyword(s):  
Mental Workload ◽  
Time Estimation ◽  
Time Of Day ◽  
Subjective Perception ◽  
Estimation Task ◽  
Related Factors ◽  
Subjective Workload ◽  
Circadian Fluctuation ◽  
Duration Estimation ◽  
Time Estimation Task

Two experiments are reported which investigated whether male and female operator duration estimation and subjective workload followed conventional circadian fluctuation. In the first experiment, twenty-four subjects performed a filled time-estimation task in a constant blacked-out, noise-reduced environment at 0800, 1200, 1600, and 2000h. In the second experiment, twelve subjects performed an unfilled time estimation task in similar conditions at 0900, 1400, and 1900h. At the termination of all experimental sessions, participants completed the NASA TLX workload assessment questionnaire as a measure of perceived mental workload. Results indicated that while physiological response followed an expected pattern, estimations of duration and subjective perception of workload showed no significant effects for time-of-day. In each of the experiments, however, there were significant differences in durational estimates and mental workload response depending upon the gender of the participant. Results are taken to support the assertion that subjective workload is responsive largely to task-related factors and indicates the important differences that may be expected due to operator gender.

Determination of the weighted mean path length of the Epstein frame

2013 ◽  
Vol 33 (1/2) ◽  
pp. 224-233 ◽  
Author(s):  
Kong Qingyi ◽  
Zhiguang Cheng ◽  
Xiaoyan Wang ◽  
Yana Fan ◽  
Lanrong Liu ◽  
...  
Keyword(s):  
Path Length ◽  
Excitation Frequency ◽  
Middle Part ◽  
Related Factors ◽  
Content Type ◽  
Different Dimensions ◽  
The Mean ◽  
Path Lengths ◽  
Transformer Core

Purpose – The purpose of this paper is to investigate the effects of the related factors on the mean path length of the Epstein frame and propose a weighted method based on the different specific losses to decide the actual mean path length of the Epstein frame. Design/methodology/approach – Two Epstein frames of different dimensions (i.e. standard 25 cm and revised 17.5 cm Epstein frame) are used in experiments, and two kinds of the mean path lengths, lm1 and lm2, are defined based on the different specific iron losses produced at the middle part of the limb and the rest of the whole frame, respectively. Findings – The mean magnetic path varies with many factors such as peak flux density, excitation frequency, permeability as well as the anisotropy of the material under test. Originality/value – The results play an important role in designing the transformer core and the building factor.

Prognostic factors for survival in patients with stage (stg) IV malignant melanoma (MM)

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. 9072-9072
Author(s):  
N. Seetharamu ◽  
H. Hamilton ◽  
T. Tu ◽  
P. Christos ◽  
I. Osman ◽  
...  
Keyword(s):  
Proportional Hazards ◽  
Univariate Analysis ◽  
Primary Melanoma ◽  
Stage Iv ◽  
Female Gender ◽  
Cox Proportional Hazards ◽  
Independent Effect ◽  
P Value ◽  
Related Factors ◽  
Ajcc Staging

9072 Background: Prognosis for survival in MM is not uniform with some pts being long-term survivors. Identifying this subset of pts may have implications on surveillance and treatment (tx). Unfortunately, prognostic data available for MM and the utility of AJCC staging in predicting survival is limited. We analyzed prospectively collected data from the NYUCI Interdisciplinary Melanoma Cooperative Group program (IMCG) to identify clinicopathological variables predictive of MM survival. Methods: We identified 185 pts enrolled in the IMCG with MM diagnosed and treated at NYUCI. Demographic, clinical, and tx-related factors were included in the analysis. Kaplan-Meier (KM) survival analysis was used to identify univariate predictors of post-stage IV survival and their independent effect was assessed in a multivariate Cox proportional hazards regression model. Results: Median age at diagnosis (dx) of metastatic MM was 64 years (22–92). Median overall survival: 13.8 months(m) (128 deaths and a median follow up of 18.6 m (4–141) for survivors). Factors identified on univariate analysis at p<0.20 were evaluated in the multivariate model ( table ). Co-morbidities, site and histology of primary melanoma, initial staging, prior loco-regional recurrences, and adjuvant tx of primary melanoma were not associated with MM survival. Univariate analysis also showed significant survival advantage (p value 0.0011) for patients with AJCC stages M1a and M1b (21.6 m and 17.2 m respectively) over those with AJCC stage M1c (9 m). Conclusions: This cohort study of MM identified female gender, nl serum LDH, nl albumin, and solitary organ involvement as independent survival predictors. Patients who received systemic therapy± local measures had survival benefit over those that had surgery and/or radiation alone suggesting a role for systemic treatment in MM. Patients with personal history of another malignancy (n=37) showed a trend towards improved survival. This novel observation needs to be validated and studied further. [Table: see text] No significant financial relationships to disclose.

scholarly journals Connectivity modulations induced by reach&grasp movements: a multidimensional approach

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pietro Caliandro ◽  
Gloria Menegaz ◽  
Chiara Iacovelli ◽  
Carmela Conte ◽  
Giuseppe Reale ◽  
...  
Keyword(s):  
Path Length ◽  
Movement Time ◽  
Insular Cortex ◽  
Arm Movement ◽  
Global Efficiency ◽  
Brodmann Areas ◽  
Topological Measures ◽  
Measuring Network ◽  
The Right ◽  
Complex Architecture

AbstractReach&grasp requires highly coordinated activation of different brain areas. We investigated whether reach&grasp kinematics is associated to EEG-based networks changes. We enrolled 10 healthy subjects. We analyzed the reach&grasp kinematics of 15 reach&grasp movements performed with each upper limb. Simultaneously, we obtained a 64-channel EEG, synchronized with the reach&grasp movement time points. We elaborated EEG signals with EEGLAB 12 in order to obtain event related synchronization/desynchronization (ERS/ERD) and lagged linear coherence between Brodmann areas. Finally, we evaluated network topology via sLORETA software, measuring network local and global efficiency (clustering and path length) and the overall balance (small-worldness). We observed a widespread ERD in α and β bands during reach&grasp, especially in the centro-parietal regions of the hemisphere contralateral to the movement. Regarding functional connectivity, we observed an α lagged linear coherence reduction among Brodmann areas contralateral to the arm involved in the reach&grasp movement. Interestingly, left arm movement determined widespread changes of α lagged linear coherence, specifically among right occipital regions, insular cortex and somatosensory cortex, while the right arm movement exerted a restricted contralateral sensory-motor cortex modulation. Finally, no change between rest and movement was found for clustering, path length and small-worldness. Through a synchronized acquisition, we explored the cortical correlates of the reach&grasp movement. Despite EEG perturbations, suggesting that the non-dominant reach&grasp network has a complex architecture probably linked to the necessity of a higher visual control, the pivotal topological measures of network local and global efficiency remained unaffected.

scholarly journals Can a Data-Driven Measure of Neuroanatomic Dementia Risk be Considered a Measure of Brain Aging?

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. 970-971
Author(s):  
Ramon Casanova ◽  
Andrea Anderson ◽  
Jamie Justice ◽  
Gwen Windham ◽  
Rebecca Gottesman ◽  
...  
Keyword(s):  
Brain Aging ◽  
A Priori ◽  
Tumor Necrosis Factor Receptor ◽  
Data Driven ◽  
Deficit Accumulation ◽  
Related Factors ◽  
Atherosclerosis Risk In Communities ◽  
Pattern Similarity ◽  
Accumulation Index ◽  
Health Related

Abstract There is an increasing interest in identifying aging-related factors which may be permissive of Alzheimer’s Disease (AD) emergence. We previously used machine learning to derive an index of neuroanatomic risk of dementia called AD pattern similarity (AD-PS) score using MRIs obtained in the Atherosclerosis Risk in Communities (ARIC) study. Here, we investigate the potential of the AD-PS scores as a brain-focused measure of biologic age. Among 1970 ARIC participants with MRI collected at ARIC Visit 5, we related AD-PS scores to three measures of aging: mortality (n=356) over 8 years of follow-up; an a priori panel of 32 proteins related to aging (N=1647); and a deficit accumulation index (DAI) based on 38 health-related measures. We found lower AD-PS scores associated with significantly lower mortality (HR=0.58, CI-95%, [0.45 - 0.75], p &lt; 0.001) after adjusting for age, race, smoking and hypertension. Among the 32 proteins, nine were significantly associated to AD-PS scores (p &lt; 0.05) with 4 remaining significant adjusting for multiple comparisons (Growth/differentiation factor 15, Tumor necrosis factor receptor superfamily member 1A and 1B and Collagen alpha-1(XVIII) chain). Finally, in a linear regression model after adjusting for age, race, sex, hypertension and smoking, AD-PS scores were associated with the DAI (p &lt; 0.001). The consistent patterns of associations suggest that a data-driven measure of AD neuroanatomic risk may be capturing aspects of biologic age in older adults.

It Ain’t What You Do, It’s the Way that You Do It! Teaching Style Affects Children’s Motivation in Track and Field Lessons

1995 ◽  
Vol 9 (3) ◽  
pp. 254-264 ◽  
Author(s):  
Marios Goudas ◽  
Stuart Biddle ◽  
Kenneth Fox ◽  
Martin Underwood
Keyword(s):  
Intrinsic Motivation ◽  
Teaching Style ◽  
Sport Activity ◽  
Track And Field ◽  
Self Report ◽  
Independent Effect ◽  
Task Orientation ◽  
Sports Activity ◽  
Task Goal ◽  
And Task

The purpose of this study was to examine the motivational effects of two different teaching styles in one sport activity. One class of 24 girls was taught track and field for 10 weeks, each lesson being taught with either a direct (practice) or a differentiated (inclusion) teaching style. After each lesson the girls completed self-report measures of intrinsic motivation and goal involvement. On course completion, 8 girls were interviewed to assess their reactions to the course. ANOVA showed that students reporting higher levels of competence, autonomy, and task orientation had higher intrinsic motivation scores throughout the course. However, teaching style was also found to have an independent effect; the differentiated style was associated with higher levels of intrinsic motivation and task goal involvement and lower levels of work avoidance involvement. A differentiated teaching style can positively influence young girls’ reactions to a sports activity independently of perceptions of goal orientations, autonomy, and competence.

scholarly journals 703. Do Patients with Drug Use-Associated Infective Endocarditis Receive Differential Care?

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S402-S403
Author(s):  
Ashley Ceniceros ◽  
Uriel Felson ◽  
Aaron Fox
Keyword(s):  
Infective Endocarditis ◽  
Drug Use ◽  
A Priori ◽  
Differential Treatment ◽  
People Who Use Drugs ◽  
Odds Ratios ◽  
Related Factors ◽  
Study Objective ◽  
Unstable Housing ◽  
Outpatient Parenteral Antimicrobial Therapy

Abstract Background Outpatient parenteral antimicrobial therapy (OPAT) is the preferred modality for long term intravenous antibiotics for infections such as infective endocarditis (IE). People with drug use-associated (DUA) infections achieve similar outcomes as those with non-DUA-infections when treated using OPAT. The study objective was to compare OPAT use between cohorts of patients with DUA-IE and non-DUA-IE. Methods This retrospective cohort study compared OPAT use for DUA-IE vs. non-DUA-IE in adults hospitalized between 1/1/15 and 9/1/19 at three Bronx, NY hospitals. We used multivariable logistic regression to assess the association between DUA-IE and discharge with OPAT, adjusting for clinically significant covariates that were decided a priori. Additional models excluded patients with unstable housing and those who left against medical advice (AMA). Figure 1: Flow chart of inclusion and exclusion criteria Results The cohort included 457 patients (346 non-DUA-IE, 111 DUA-IE). Compared to those with non-DUA-IE, DUA-IE patients were younger (mean age 54.9 years), more commonly male (65.8%), Hispanic (44.1%), Medicaid insured (40.5%), and undomiciled (9%). In models adjusting for age, sex, race/ethnicity, insurance, year of admission, length of stay, socioeconomic status, Charlson Comorbidity Index, MICU admissions, and infectious disease consults, DUA-IE patients had significantly lower odds of being discharged with OPAT than non-DUA-IE patients (aOR 0.16, 95% CI 0.08, 0.34). Odds of being discharged with OPAT remained lower for DUA-IE patients after excluding unstably housed patients (aOR 0.17, 95% CI 0.09, 0.38) and patients who left AMA (aOR 0.23, 95% CI 0.11, 0.47). Table 1: Non-DUA-IE and DUA-IE Patient Characteristics Table 2: Unadjusted and Adjusted Odds Ratios for Discharge with OPAT Table 3: Odds Ratios for Discharge with OPAT Among Patients Stably Housed and Retained in Care Conclusion Patients with DUA-IE were discharged with OPAT significantly less than those with non-DUA-IE, and patients having unstable housing or leaving AMA did not account for these differences. These data do not elucidate whether differential treatment was clinically appropriate, but other studies have demonstrated safety and effectiveness of OPAT in DUA-infections. Understanding whether addressable clinician-related factors, including their attitudes toward people who use drugs, contribute to differential treatment is an important next step in this research. Disclosures All Authors: No reported disclosures

scholarly journals Towards robust and replicable sex differences in the intrinsic brain function of autism

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Dorothea L. Floris ◽  
José O. A. Filho ◽  
Meng-Chuan Lai ◽  
Steve Giavasis ◽  
Marianne Oldehinkel ◽  
...  
Keyword(s):  
Sex Differences ◽  
Large Scale ◽  
A Priori ◽  
Gaussian Random Field ◽  
Occipital Cortex ◽  
Posterior Cingulate Cortex ◽  
Brain Organization ◽  
Related Factors ◽  
Females With Autism ◽  
Main Effects

Abstract Background Marked sex differences in autism prevalence accentuate the need to understand the role of biological sex-related factors in autism. Efforts to unravel sex differences in the brain organization of autism have, however, been challenged by the limited availability of female data. Methods We addressed this gap by using a large sample of males and females with autism and neurotypical (NT) control individuals (ABIDE; Autism: 362 males, 82 females; NT: 409 males, 166 females; 7–18 years). Discovery analyses examined main effects of diagnosis, sex and their interaction across five resting-state fMRI (R-fMRI) metrics (voxel-level Z > 3.1, cluster-level P < 0.01, gaussian random field corrected). Secondary analyses assessed the robustness of the results to different pre-processing approaches and their replicability in two independent samples: the EU-AIMS Longitudinal European Autism Project (LEAP) and the Gender Explorations of Neurogenetics and Development to Advance Autism Research. Results Discovery analyses in ABIDE revealed significant main effects of diagnosis and sex across the intrinsic functional connectivity of the posterior cingulate cortex, regional homogeneity and voxel-mirrored homotopic connectivity (VMHC) in several cortical regions, largely converging in the default network midline. Sex-by-diagnosis interactions were confined to the dorsolateral occipital cortex, with reduced VMHC in females with autism. All findings were robust to different pre-processing steps. Replicability in independent samples varied by R-fMRI measures and effects with the targeted sex-by-diagnosis interaction being replicated in the larger of the two replication samples—EU-AIMS LEAP. Limitations Given the lack of a priori harmonization among the discovery and replication datasets available to date, sample-related variation remained and may have affected replicability. Conclusions Atypical cross-hemispheric interactions are neurobiologically relevant to autism. They likely result from the combination of sex-dependent and sex-independent factors with a differential effect across functional cortical networks. Systematic assessments of the factors contributing to replicability are needed and necessitate coordinated large-scale data collection across studies.

scholarly journals Dementia and the risk of short-term readmission and mortality after a pneumonia admission

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0246153
Author(s):  
Susanne Boel Graversen ◽  
Henrik Schou Pedersen ◽  
Annelli Sandbaek ◽  
Catherine Hauerslev Foss ◽  
Victoria Jane Palmer ◽  
...  
Keyword(s):  
Older Persons ◽  
Medication Use ◽  
Independent Effect ◽  
Sociodemographic Characteristics ◽  
Care Planning ◽  
Short Term ◽  
Related Factors ◽  
Short Term Mortality ◽  
Essential Knowledge ◽  
Rate Ratios

Background At time of discharge after a pneumonia admission, care planning for older persons with dementia is essential. However, care planning is limited by lack of knowledge on the short-term prognosis. Aim To investigate 30-day mortality and readmission after hospital discharge for pneumonia in persons with versus without dementia, and to investigate how these associations vary with age, time since discharge, and medication use. Methods Using the Danish registries, we investigated 30-day mortality and readmission in persons (+65 years) discharged after pneumonia in 2000–2016 (N = 298,872). Adjusted mortality rate ratios (aMRRs) and incidence rate ratios (aIRRs) were calculated for persons with versus without dementia, and we investigated if these associations varied with use of benzodiazepines, opioids, and antipsychotics, and with age and time since discharge. Results Among 25,948 persons with dementia, 4,524 died and 5,694 were readmitted within 30 days. The risk of 30-day mortality was 129% higher (95% CI 2.21–2.37) in persons with versus without dementia after adjustment for sociodemographic characteristics, admission-related factors, and comorbidities. Further, the highest mortality risk was found in persons with both dementia and use of antipsychotics (aMRR: 3.39, 95% CI 3.19–3.59); 16% of deaths in this group could not be explained by the independent effect of each exposure. In those with dementia, the highest aMRRs were found for the youngest and for the first days after discharge. The risk of 30-day readmission was 7% higher (95% CI 1.04–1.10) in persons with versus without dementia. In those with dementia, the highest aIRRs were found for the first days after discharge. Conclusions Dementia was associated with higher short-term mortality after pneumonia, especially in users of antipsychotics, and with slightly higher readmission, especially in the first days after discharge. This is essential knowledge in the care planning for persons with dementia who are discharged after a pneumonia admission.

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