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.

Simple auditory and visual interruptions of a continuous visual tracking task: modality effects and time course of interference.

Research has produced conflicting evidence regarding whether performance of an on-going visual task is disrupted more by an interruption from a visual or an auditory alert. Tasks and alerts studied to date have been complex or idiosyncratic. This experiment examined how the modality of simple alerts-visual icons or auditory tones-affected performance of an on-going visual task. Participants (58 females and 4 males) tracked a visual target while performing a choice reaction time task in response to alerts. Visual alerts were more harmful to performance of the tracking task. Dual task workload was lowest with an auditory alert, provided there was not noise present. Interruptions affected tracking task performance for around 1500 ms. Results supported the predictions of Multiple Resources Theory and showed no evidence of auditory preemption. In practical applications for which an on-going visual task is interrupted, auditory alerts may be less disruptive and may reduce perceived workload. Practitioner Summary: Many practical scenarios involve on-going visual tasks that are interrupted by simple alerts requiring a simple response. Auditory alerts may be less disruptive than visual alerts and may reduce perceived workload. A conservative estimate is that the effects of even simple interruptions will last a minimum of 1500 ms. Abbreviations: ANOVA: analysis of variance; LSD: least significant difference; TLX: task load index.

Quantity and quality limit detritivore growth: mechanisms revealed by ecological stoichiometry and co-limitation theory.

Resource quantity and quality are fundamental bottom-up constraints on consumers. Best understood in autotroph-based systems, co-occurrence of these constraints may be common but remains poorly studied in detrital-based systems. Here, we used a laboratory growth experiment to test limitation of the detritivorous caddisfly larvae Pycnopsyche lepida across a concurrent gradient of oak litter quantity (food supply) and quality (phosphorus : carbon [P:C ratios]). Growth increased simultaneously with quantity and quality, indicating co-limitation across the resource gradients. We merged approaches of ecological stoichiometry and co-limitation theory, showing how co-limitation reflected shifts in C and P acquisition throughout homeostatic regulation. Increased growth was best explained by elevated consumption rates and improved P assimilation, which both increased with elevated quantity and quality. Notably, C assimilation efficiencies remained unchanged and achieved maximum 18% at low quantity despite pronounced C limitation. Detrital C recalcitrance and substantive post-assimilatory C losses probably set a minimum quantity threshold to achieve positive C balance. Above this threshold, greater quality enhanced larval growth probably by improving P assimilation toward P-intensive growth. We suggest this interplay of C and P acquisition contributes to detritivore co-limitation, highlighting quantity and quality as potential simultaneous bottom-up controls in detrital-based ecosystems, including under anthropogenic change like nutrient enrichment.

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.

Using the center of gravity to help blind people measure water levels in bottles.

People who are blind struggle to gauge water levels in bottles by weight alone. This work shows that combining information about a filled bottle's weight and center of gravity can enhance the accuracy of measuring the water level. Bumps were attached to the sides of cylindrical bottles at positions corresponding to the centers of gravity of water levels between 4 and 9. These bumps allow individuals to use additional information about the center of gravity to measure the water level in the bottle. Eight subjects who were blind participated in the experiment, and the results indicated that using the center of gravity method with a plastic bottle was the most accurate, with an average water level error of 0.04, but it took 57.83 seconds. Contrarily, using the weight method, the plastic bottle yielded the fastest results, with an average time of 6.51 seconds, but it led to an average water level error of 0.88.

Examining perceptions, selections, and products in undergraduates' learning from multiple resources.

BACKGROUND: When learning about complex topics using the Internet, students commonly encounter a multitude of textual, non-textual (e.g., images and graphs), and multimedia (e.g., videos) resources. Yet students' learning from multiple texts and multiple (non-textual) resources (MT-MR learning) has received insufficient consideration in the literature. AIMS: We examine the associations among (1) undergraduates' conceptions of reasons for multiple resource access, (2) log-data of resource use when completing a MT-MR task, and (3) writing performance. SAMPLE: Participants were 72 undergraduate students in the United States. METHODS: Undergraduates were provided with a library of five texts and one video, with the option of accessing supplemental data (e.g., graphs and maps) in association with each resource. Log-data (e.g., time and supplemental data access) of undergraduates' resource use were collected. Undergraduates were then asked to compose a research report and to describe what they considered the purpose of multiple resource access to be. RESULTS: Four types of conceptions were identified, reflecting a desire to (1) access a lot of information, (2) understand multiple perspectives, (3) corroborate and evaluate information, and (4) develop a personal understanding of a given topic. Undergraduates who considered corroboration and evaluation to be the purpose of multiple resource access were more likely to access more supplemental data sources and performed better on a multiple resource learning task. CONCLUSIONS: Undergraduates in our sample held conceptions largely similar to, but in some aspects distinct from, those identified by Barzilai and Zohar (Cognit Instruct, 30, 2012, 39). Conceptions were associated with resource access during task completion and with writing performance.

Application of the Ostrom framework in the analysis of a social-ecological system with multiple resources in a marine protected area.

The framework proposed by Ostrom (2009) has become one of the most utilized tools to address the complexity of social-ecological systems. Most cases use this framework to analyze the systems from the perspective of a single resource unit. However, the livelihoods in several coastal communities are diverse, so that the users interact with multiple common-pool resources, which makes their analysis difficult. In this sense, it is important to identify the key elements of management to achieve the sustainable use of the resources. In this study, we were able to do this in a coastal community where commercial fishing, ecotourism, and recreational fishing coexist. The system of interest, located in the state of Quintana Roo, Mexico, was subdivided by resource type using a multi-method approach to data collection including surveys, interviews, and records review. A conceptual map was developed that shows how the second-tier variables are integrated through the governance and actors with the biophysical system. The actors involved in lobster fishing achieved a more complex governance system, followed by the ecotourism and recreational fishing; the complexity of the governance was related with the equity level of the actors. The analysis revealed the research gaps to develop management strategies and improve the sustainability of the system.

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.