Auditory versus visual spatial stimulus-response mappings in tracking and discrete dual task performance: implications for human-machine interface design.

A discrete four-choice response task with auditory signal presentation and a joystick-controlled visual tracking task was used to investigate how spatial compatibility influences the dual-task performance of different display-control settings. It was found that the more incompatible the stimulus-response mapping, the longer the delay for both tasks, presumably because of the longer stimulus encoding time required for the incompatible conditions. A comparison of the findings of this study with those of past experiments on visual visual setting shows that the dual-task performance in a cross-modality (auditory visual) setting was significantly better than that in an intra-modality (visual visual) setting because of visual scanning required in the intra-modal dual tasks. However, when the locations of visual visual tasks were close enough such that ambient and focal vision was concurrently used for information processing, the dual-task performance of intra-modality (visual visual) configuration was slightly better than that of the cross-modality (auditory visual) configuration. Practitioner Summary: The effect of spatial compatibility with auditory signal presentation in multiple display-control configurations was examined in a dual-task paradigm. The results provided important and useful ergonomics design implications and consequent recommendations for intra- and cross- modal interface design. The results should facilitate human-machine system design and improve overall system performance.

Early Course of Inflammatory Bowel Disease in a Population-Based Inception Cohort Study From 8 Countries in Asia and Australia.

BACKGROUND & AIMS: The incidence of inflammatory bowel disease (IBD) is increasing in Asia, but little is known about disease progression in this region. The Asia-Pacific Crohn's and Colitis Epidemiology Study was initiated in 2011, enrolling subjects from 8 countries in Asia (China, Hong Kong, Indonesia, Sri Lanka, Macau, Malaysia, Singapore, and Thailand) and Australia. We present data from this ongoing study. METHODS: We collected data on 413 patients diagnosed with IBD (222 with ulcerative colitis [UC], 181 with Crohn's disease [CD], 10 with IBD unclassified; median age, 37 y) from 2011 through 2013. We analyzed the disease course and severity and mortality. Risks for medical and surgical therapies were assessed using Kaplan-Meier analysis. RESULTS: The cumulative probability that CD would change from inflammatory to stricturing or penetrating disease was 19.6%. The cumulative probabilities for use of immunosuppressants or anti-tumor necrosis factor agents were 58.9% and 12.0% for patients with CD, and 12.7% and 0.9% for patients with UC, respectively. Perianal CD was associated with an increased risk of anti-tumor necrosis factor therapy within 1 year of its diagnosis (hazard ratio, 2.97; 95% confidence interval, 1.09-8.09). The cumulative probabilities for surgery 1 year after diagnosis were 9.1% for patients with CD and 0.9% for patients with UC. Patients with CD and penetrating disease had a 7-fold increase for risk of surgery, compared with patients with inflammatory disease (hazard ratio, 7.67; 95% confidence interval, 3.93-14.96). The overall mortality for patients with IBD was 0.7%. CONCLUSIONS: In a prospective population-based study, we found that the early course of disease in patients with IBD in Asia was comparable with that of the West. Patients with CD frequently progress to complicated disease and have accelerated use of immunosuppressants. Few patients with early stage UC undergo surgery in Asia. Increasing our understanding of IBD progression in different populations can help optimize therapy and improve outcomes.

Environmental risk factors in inflammatory bowel disease: a population-based case-control study in Asia-Pacific.

OBJECTIVE: The rising incidence of inflammatory bowel disease in Asia supports the importance of environmental risk factors in disease aetiology. This prospective population-based case-control study in Asia-Pacific examined risk factors prior to patients developing IBD. DESIGN: 442 incident cases (186 Crohn's disease (CD); 256 UC; 374 Asians) diagnosed between 2011 and 2013 from eight countries in Asia and Australia and 940 controls (frequency-matched by sex, age and geographical location; 789 Asians) completed an environmental factor questionnaire at diagnosis. Unconditional logistic regression models were used to estimate adjusted ORs (aOR) and 95% CIs. RESULTS: In multivariate model, being breast fed >12 months (aOR 0.10; 95% CI 0.04 to 0.30), antibiotic use (aOR 0.19; 0.07 to 0.52), having dogs (aOR 0.54; 0.35 to 0.83), daily tea consumption (aOR 0.62; 0.43 to 0.91) and daily physical activity (aOR 0.58; 0.35 to 0.96) decreased the odds for CD in Asians. In UC, being breast fed >12 months (aOR 0.16; 0.08 to 0.31), antibiotic use (aOR 0.48; 0.27 to 0.87), daily tea (aOR 0.63; 0.46 to 0.86) or coffee consumption (aOR 0.51; 0.36 to 0.72), presence of hot water tap (aOR 0.65; 0.46 to 0.91) and flush toilet in childhood (aOR 0.71; 0.51 to 0.98) were protective for UC development whereas ex-smoking (aOR 2.02; 1.22 to 3.35) increased the risk of UC. CONCLUSIONS: This first population-based study of IBD risk factors in Asia-Pacific supports the importance of childhood immunological, hygiene and dietary factors in the development of IBD, suggesting that markers of altered intestinal microbiota may modulate risk of IBD later in life.

Tracking and discrete dual task performance with different spatial stimulus-response mappings.

The effect of spatial compatibility on dual-task performance for various display-control configurations was studied using a tracking task and a discrete four-choice response task. A total of 36 participants took part in this study, and they were asked to perform the primary tracking task while at the same time to respond to an occasional signal. Different levels of compatibility between the stimuli and responses of the discrete response task were found to lead to different degrees of influence on the tracking task. However, degradation of performance was observed for both tasks, which was probably due to resource competition for the visual and spatial resources required for simultaneous task operation and required for bimanual responses. No right-left prevalence effect for the spatial compatibility task was observed in this study, implying that the use of unimanual two-finger responses may not provide the right conditions for a significant effect in the horizontal right-left dimension. PRACTITIONER SUMMARY: The effect of spatial compatibility in multiple display-control configurations was examined in a dual-task paradigm. The analyses of keen competition for visual and spatial resources in processing the dual tasks under different degrees of stimulus-response compatibility provide useful ergonomics design implications and recommendations for visual interfaces requiring frequent visual scanning.

Incidence and phenotype of inflammatory bowel disease based on results from the Asia-pacific Crohn's and colitis epidemiology study.

BACKGROUND & AIMS: Inflammatory bowel diseases (IBD) are becoming more common in Asia, but epidemiologic data are lacking. The Asia-Pacific Crohn's and Colitis Epidemiology Study aimed to determine the incidence and phenotype of IBD in 8 countries across Asia and in Australia. METHODS: We performed a prospective, population-based study of IBD incidence in predefined catchment areas, collecting data for 1 year, starting on April 1, 2011. New cases were ascertained from multiple overlapping sources and entered into a Web-based database. Cases were confirmed using standard criteria. Local endoscopy, pathology, and pharmacy records were searched to ensure completeness of case capture. RESULTS: We identified 419 new cases of IBD (232 of ulcerative colitis [UC], 166 of Crohn's disease [CD], and 21 IBD-undetermined). The crude annual overall incidence values per 100,000 individuals were 1.37 for IBD in Asia (95% confidence interval: 1.25-1.51; 0.76 for UC, 0.54 for CD, and 0.07 for IBD-undetermined) and 23.67 in Australia (95% confidence interval: 18.46-29.85; 7.33 for UC, 14.00 for CD, and 2.33 for IBD-undetermined). China had the highest incidence of IBD in Asia (3.44 per 100,000 individuals). The ratios of UC to CD were 2.0 in Asia and 0.5 in Australia. Median time from symptom onset to diagnosis was 5.5 months (interquartile range, 1.4-15 months). Complicated CD (stricturing, penetrating, or perianal disease) was more common in Asia than Australia (52% vs 24%; P = .001), and a family history of IBD was less common in Asia (3% vs 17%; P < .001). CONCLUSIONS: We performed a large-scale population-based study and found that although the incidence of IBD varies throughout Asia, it is still lower than in the West. IBD can be as severe or more severe in Asia than in the West. The emergence of IBD in Asia will result in the need for specific health care resources, and offers a unique opportunity to study etiologic factors in developing nations.

Effect of color contrast on visual lobe shape characteristics.

This study examined the effects of the color contrast of target and background objects on visual lobe area and shape characteristics. For visual lobe mapping the participants had to locate a single colour target amongst a homogeneous background of non-targets during a brief presentation. Targets of six different colors (red, yellow, green, cyan, blue, purple) were tested, the non-targets were black and the background was metallic grey. The results showed that color contrast did not affect visual lobe parameters under the constant luminance contrast condition of 6:1 tested in the experiment. Subjective preference evaluations showed that the blue and purple targets resulted in the highest visual comfort and overall preference, respectively, while the yellow target was the most negatively rated. The color preferences here were somewhat different from the previous color combination studies. It might be due in part to the constant luminance contrast and display polarity used here.

Effect of display polarity and luminance contrast on visual lobe shape characteristics.

The effect of display polarity and luminance contrast on visual lobe (effective visual field) shape characteristics was studied using three levels of luminance contrast with combinations of positive and negative polarities. The binocular effective visual field for a detection task, with a peripherally presented target (V) embedded in a homogeneous competing background (Xs), was mapped on 24 imaginary axes passing through the fixation point. The results showed that visual lobes mapped using positive polarity were statistically larger in area, rounder and more regular in shape than those for negative polarity. The medium contrast condition lobes were more symmetric and regular than low contrast condition lobes, and lobe area and perimeter increased with increasing luminance contrast ratio. Under the interaction of positive polarity and high luminance contrast, visual lobes were found to be larger, smoother and rounder. The high level of luminance and contrast however resulted in a higher degree of visual discomfort. The results indicated that positive polarity and contrast of medium (26:1) to high (41:1) levels are possible display settings for better visual lobe characteristics and better anticipated search performance. Practitioner Summary: The effect of display polarity and luminance contrast on visual lobe shape characteristics was examined with uniform stimulus materials in this study. The results help to identify the optimum display settings for luminance contrast and display polarity to enhance lobe shape characteristics and hence search performance in industrial inspection tasks.

Tracking and discrete dual task performance for different visual spatial stimulus-response mappings with focal and ambient vision.

The effect of spatial compatibility for various display-control configurations on human performance was studied with a dual-task paradigm using a tracking task and a discrete response task. Degradation of performance on both tasks within the visual modality was observed and was considered to be most likely due to resource competition resulting from simultaneous task operation. It was found that the more complicated the mapping for the discrete spatial compatibility response task, the more severe the interference with the tracking task. Although performance on both the tracking and spatial response tasks was impaired, the magnitude of impairment was not as great as expected, implying that focal and ambient vision required for the tracking task and spatial task, respectively, might be deployed, at least partly, from separate resources. Participants here seemed to successfully use focal vision for tracking and ambient vision for identifying signal lights concurrently, reducing the expected keen competition for visual resources.

Stereotypes for lever-tap operation.

BACKGROUND: Lever-operated taps have become more popular and are commonly used in operating theatres, food preparation areas and where users have poor strength; however, there is very little data available for user expectations on tap operation. Thus, an experiment on dual lever-operated water tap (faucets) was conducted with the aim of for providing information for improved design. OBJECTIVE: This study aims to compare different lever-tap designs and their stereotypes adopted by the end-user to operate them also to verify the stereotypes for increasing or decreasing the water flow. METHODS: 240 participants were requested to rotate the lever tap to indicate direction for increasing and decreasing water flow with simulated hardware, using actual taps placed at the top of a simulated washbasin. Nine initial positions of the lever were used for increasing and decreasing flows, ranging from the ends of both levers facing outward from the bowl center to the ends of both levers facing inward. All levers operated in the horizontal plane. RESULTS: Strong stereotypes (greater than 80%) for several initial lever orientations were found for increasing water flow, especially when the initial lever end positions were facing outwards. However, for different initial positions at which participants were told that the water was flowing and the flow was to be decreased, no strong stereotypes existed. CONCLUSIONS: The stereotypes for increasing water flow of dual-lever taps were strong, whereas those for decreasing water flow were weak and hence the stereotype reversibility was also weak. In terms of user expectations, lever taps do not show any great advantage over cross-taps in terms of operator expectations for increasing and decreasing water flow.

Infection-related hospitalizations in the first year after inflammatory bowel disease diagnosis.

OBJECTIVE: With the rapid increase in the incidence of inflammatory bowel disease (IBD) in Asia, the natural course of the early phase of disease in these patients remains poorly defined. This study aimed to determined the incidence and characteristics of infection-related hospitalization in the first year in patients newly diagnosed with IBD in Hong Kong SAR, China. METHODS: Patients newly diagnosed with IBD and enrolled in the territory-wide Hong Kong IBD Registry were identified. Details of their hospitalization within the first 12 months after diagnosis were retrieved and analyzed. RESULTS: Altogether 433 newly diagnosed IBD patients were enrolled, including 188 with Crohn's disease (CD), 230 with ulcerative colitis (UC) and 15 with IBD-unclassified (IBD-U). Among them, 110 (25.4%) had at least one unscheduled hospitalization in the first year and 34 (7.9%) had infection-related hospitalization, leading to 43 (23.4%) of total hospitalizations. Gastrointestinal tract (30.2%), respiratory tract (34.9%) and skin and soft tissues (11.6%) were the most common sites of infection. Bacterial and viral infections accounted for 46.7% and 20.8% of hospitalizations for infection, respectively. Common identified pathogens included Clostridium difficile (16.3%) and Cytomegalovirus (11.6%). Multivariate analysis found that patient's age (odds ratio [OR] 1.03, 95% confidence interval [CI] 1.01-1.06) and the presence of comorbidity (OR 2.32, 95% CI 1.05-5.13) were significantly associated with hospitalization from infection in IBD patients. CONCLUSIONS: Infection-related hospitalizations were found in 7.9% of newly diagnosed IBD patients within the first year after diagnosis in Hong Kong, which accounted for about one-quarter of all unscheduled hospitalizations. Elder patients with concurrent illnesses were at higher risk.

Natural History of Elderly-onset Ulcerative Colitis: Results from a Territory-wide Inflammatory Bowel Disease Registry.

BACKGROUND AND AIMS: Data on the natural history of elderly-onset ulcerative colitis [UC] are limited. We aimed to investigate clinical features and outcomes of patients with elderly-onset UC. METHODS: Patients with a confirmed diagnosis of UC between 1981 and 2013, from 13 hospitals within a territory-wide Hong Kong Inflammatory Bowel Disease Registry, were included. Clinical features and outcomes of elderly-onset patients, defined as age ≥ 60 years at diagnosis, were compared with those of non-elderly-onset disease [< 60 years at diagnosis]. RESULTS: We identified 1225 patients, of whom 12.8% [157/1225; 56.1% male] had elderly-onset UC. Median duration of follow-up was 11 years [interquartile range, 6-16 years]. Age-specific incidence of elderly-onset UC increased from 0.1 per 100000 persons before 1991 to 1.3 per 100000 persons after 2010. There were more ex-smokers [32.2% vs. 12.2%, p < 0.001] and higher proportion of comorbidities [p < 0.001] in elderly-onset than non-elderly-onset patients. Disease extent, corticosteroids, immunosuppressants use, and colectomy rates were similar between the two groups. Elderly-onset disease was an independent risk factor for cytomegalovirus infection [odds ratio 2.9, 95% confidence interval 1.6-5.2, p < 0.001]. More elderly-onset patients had Clostridium difficile infection [11.0% vs. 5.4%, p = 0.007], hospitalisation for UC exacerbation [50.6% vs. 41.8%, p = 0.037], colorectal cancer [3.2% vs. 0.9%, p = 0.033], all-cause mortality [7.0% vs. 1.0%, p < 0.001], and UC-related mortality [1.9% vs. 0.2%, p = 0.017] than non-elderly-onset patients. CONCLUSIONS: Elderly-onset UC patients are increasing in number. These patients have higher risk of opportunistic infections, hospitalisation, colorectal cancer, and mortality than non-elderly-onset patients. Management and therapeutic strategies in this special group need careful attention.

Bimanual and unimanual convergent goal-directed movement times.

Three experiments are reported, investigating the effects of using 1 or 2 hands when making convergent low index of difficulty (ID) and visually controlled movements (2 hands meeting together). The experiments involved movements in four different cases-a probe held in the right hand and moved to a target held in the stationary left hand, vice versa of this arrangement, both hands moving with the probe in the right hand and target in the left hand, and vice-versa of this arrangement. Experiments were the standard Fitts' paradigm, moving a pin into a hole and a low-ID task. In Fitts' task, 2-hand movements were faster than 1 hand only at higher IDs; this was also the case in the pin-to-hole transfer task and the movement times were lower when the pin was held in the preferred hand. Movements made with low ID showed a small effect of 1- or 2-handed movements, with the effective amplitude of the movement being reduced by about 20% when 2 hands were used.

Preference for newspaper size.

The past few years has seen a change in the size of newspapers, with publishers moving to a smaller size format. Five 'standard' newspaper sizes are used in different countries: Broadsheet, Rhensch, Tabloid, Tall Tabloid and Berliner. These papers vary in both width and height of pages and hence there are implications for human reading comfort, which may be dependent on reading location such as on a lounge chair or on a train. Experiments were carried out to determine preferences for the different sizes and to relate these preferences to the geometric characteristics of the newspapers. For both comfortable and cramped/uncomfortable reading conditions, the rank order of preference for paper types was, from least to most-preferred, Broadsheet, Rhensch, Berliner, Tall Tabloid and Tabloid. Preferences were much stronger when determined in cramped/uncomfortable reading conditions, where most comparisons were significantly different. There was good correlation between participant ratings on several scales and preference, where most factors were related to comfort of holding and controlling the paper.

Effects of line length, line spacing, and line number on proofreading performance and scrolling of Chinese text.

OBJECTIVE: The main purpose of this study was to investigate the effects and interactions of line length, line number, and line spacing on Chinese screen-based proofreading performance and amount of scrolling. BACKGROUND: Proofreading is an important process, and much of it is now done on screen. The Chinese language is increasingly important, but very little work has been done on the factors that affect proofreading performance for Chinese passages. METHOD: Three display factors related to screen size, namely line length, line number, and line spacing, were selected to be investigated in an experiment to determine their effects on proofreading performance and amount of scrolling. Correlations between proofreading performance in time and accuracy and scrolling amount were also analyzed. RESULTS: The results showed that line number and line spacing had significant main and interaction effects on both proofreading time and detection rate. Line length and line number influenced scrolling amount significantly, but there was no interaction effect for scrolling. Scrolling amount was negatively correlated with proofreading time and typo detection rate such that more scrolling movement was associated with faster proofreading, but lower detection rate. There was a trade-off between time and accuracy. CONCLUSION: For balancing time and detection rate and improving performance for on-screen Chinese proofreading, the display setting of medium line length (36 characters per line) with four lines and 1.5 line spacing should be used. APPLICATION: The findings provide information and recommendations for display factors and the screen design that should prove useful for improving proofreading time and accuracy.