Dual computer displays reduce extraneous cognitive load

Dual display desktop computers are becoming more prevalent in the home, workplace, and schools, yet there has been little research into how learning and productivity are impacted by having a second display. One useful method in exploring this question is to measure cognitive load during an intensive learning event. This study compared perceived cognitive load among participants in a military training program using one or two computer displays. Participants using dual monitors reported lower unnecessary cognitive load than participants using one monitor. The implications of these findings for theory and practice are discussed.     

General framework for measuring the optical characteristics of displays under ambient illumination

A measurement and analysis framework is described that allows a generalized treatment of display ambient performance. The proposed methodology considers the reflection and transmission properties of the display in order to evaluate its on‐screen characteristics under arbitrary illumination conditions. New transmission methods and metrics are developed to compliment the traditional reflection methods. The utility of this framework is demonstrated by evaluating the photometric and colorimetric qualities of an LCD and OLED transparent display for a wide range of ambient lighting environments.     

Towards measuring cognitive load through multimodal physiological data

Cognition, Technology & Work - Cognitive load plays an important role during learning and working, as it has been linked to well-functioning cognitive processes, performance, burnout and...     

Modeling the cognitive content of displays

An approach for measuring the cognitive complexity of visual displays is discussed and applied to a dynamic display of avionic information. A semantic network formalism is used to model two interrelated knowledge systems, world knowledge and display knowledge. The information the operator receives during training about the general display format characteristics and the task requirements, along with other previously stored information, constitutes world knowledge. The semantic content of a particular configuration of information encountered during task performance constitutes display knowledge. Four orthogonal predictor measures of cognitive complexity were derived from the networks. In an experiment three of the orthogonal predictors were significantly correlated with task performance. After averaging across operators, the three significant predictors accounted for 99% of the variation of display effectiveness. Results indicate that a model of cognitive complexity based on a semantic network formalism may provide a useful technique for quantitatively evaluating the quality of competing display format concepts.     

Stylized ambient displays of digital media collections

The falling cost of digital cameras and camcorders has encouraged the creation of massive collections of personal digital media. However, once captured, this media is infrequently accessed and often lies dormant on users' PCs. We present a system to breathe life into home digital media collections, drawing upon artistic stylization to create a “Digital Ambient Display” that automatically selects, stylizes and transitions between digital contents in a semantically meaningful sequence. We present a novel algorithm based on multi-label graph cut for segmenting video into temporally coherent region maps. These maps are used to both stylize video into cartoons and paintings, and measure visual similarity between frames for smooth sequence transitions. The system automatically structures the media collection into a hierarchical representation based on visual content and semantics. Graph optimization is applied to adaptively sequence content for display in a coarse-to-fine manner, driven by user attention level (detected in real-time by a webcam). Our system is deployed on embedded hardware in the form of a compact digital photo frame. We demonstrate coherent segmentation and stylization over a variety of home videos and photos. We evaluate our media sequencing algorithm via a small-scale user study, indicating that our adaptive display conveys a more compelling media consumption experience than simple linear “slide-shows”.     

Effects of ambient illuminance on users' visual performance using various electronic displays

Abstract— This study investigated the effect of ambient illuminance (50, 500, 1500, 3000, 6000, and 9000 lx) on participants' visual performance using four electronic displays (conventional LCD under transmissive mode, conventional LCD under reflective mode, Ch‐LC display, and E‐ink display). Analysis results indicate that participants' visual performance shows significant difference under various ambient illuminance and electronic displays. The interaction between ambient illuminance and electronic display also has significant effect on participants' visual performance. When participants use the conventional LCD under transmissive mode, ambient luminance has no significant effect on participants' visual performance. However, participants' visual performance is significantly different under various ambient illuminances using the conventional LCD under reflective mode, Ch‐LC display, and E‐ink display. The conventional LCD under transmissive mode is the only choice at a lower illuminance of 50 lx. Higher illuminance (500 lx) for E‐ink displays may result in as good a performance as the conventional LCD under transmissive mode; nevertheless, much higher illuminance (1500 lx) for the conventional LCD under reflectance mode and Ch‐LC display may achieve better performance.     

Verification-guided modelling of salience and cognitive load

Well-designed interfaces use procedural and sensory cues to increase the cognitive salience of appropriate actions. However, empirical studies suggest that cognitive load can influence the strength of those cues. We formalise the relationship between salience and cognitive load revealed by empirical data. We add these rules to our abstract cognitive architecture, based on higher-order logic and developed for the formal verification of usability properties. The interface of a fire engine dispatch task from the empirical studies is then formally modelled and verified. The outcomes of this verification and their comparison with the empirical data provide a way of assessing our salience and load rules. They also guide further iterative refinements of these rules. Furthermore, the juxtaposition of the outcomes of formal analysis and empirical studies suggests new experimental hypotheses, thus providing input to researchers in cognitive science.     

用户认知驱动的VR自然交互认知负荷研究

针对目前虚拟现实自然交互系统中用户认知负荷难以量化问题,以量化认知负荷为目的,提出一种基于概率神经网络的多通道信息融合模型。首先根据认知理论建立“认知—行为—环境”框架,并在此基础上研究用户认知的数学表征（方法,过程,机理）,构建多通道认知模型;然后将多通道信息融合方法引入虚拟现实自然交互系统,建立一种面向虚拟现实自然交互系统的认知负荷模型;通过VR隧道应急救援系统实验对系统中用户认知进行验证。验证结果表明,具体提出的认知负荷模型具有一定的可行性。     

Predicting the viewing direction performance of e‐paper displays with front light under ambient lighting conditions

The inherent advantages of reflective e‐paper displays (EPD) – wide viewing direction range and excellent readability even under bright sunlight – can be extended into low‐light conditions by the addition of an integrated lighting unit (ILU) such as a front light. A methodology for predicting the viewing direction dependence of ambient contrast and color from display measurements and illumination models is here applied to reflective EPD where the ILU is switched on. The predictions can be used to optimize task lighting. The ILU improves the indoor performance of EPD without compromising their superior daylight performance.     

The attention-guiding effect and cognitive load in the comprehension of animations

To be effective, instructional animations should avoid causing high extraneous cognitive load imposed by the high attentional requirements of selecting and processing relevant elements. In accordance with the attention-guiding principle (Bétrancourt, 2005), a study was carried out concerning the impact of cueing on cognitive load and comprehension of animations which depicted a dynamic process in a neurobiology domain. Cueing consisted of zooming in important information at each step of the process. Thirty-six undergraduate psychology students were exposed to an animation three times. Half of the participants received an animation without cueing while the other half received the same animation with cueing. Measures of cognitive load and comprehension performance (questions on isolated elements and on high-element interactivity material) were administered twice, after one and three exposures to the animation. The analyses revealed two main results. First, extraneous cognitive load was reduced by cueing after three exposures. Second, retention of the isolated elements was improved in both animation groups, whereas comprehension of high-element interactive material (i.e., the causal relations between elements) increased only in the cueing condition. Furthermore, a problem solving task showed that cueing supported the development of a more elaborate mental model.     

Effects of ambient illuminance and electronic displays on users' visual performance for young and elderly users

Abstract— This study investigated the effects of age (young participants aged 20–30 and elderly participants older than 60), ambient illuminance (50, 500, 1 500, 3000, 6000, and 9000 lx) on participants' visual performance when using various electronic displays (conventional transmissive LCD, Ch‐LC display, and E‐ink display). Overall, the results indicated that participants' visual performance showed sign if icant difference among various ambient il luminance cond itions, electronic displays, and between two groups of participants. Significantly different visual performance was observed between young and elderly participants. The interaction among ambient illuminance, type of electronic display, and age had a significant effect on participants' visual performance. When participants used the E‐ink display, both young and elderly participants had significantly worse visual performance under an ambient illuminance of 50 lx compared to other illuminance settings. When participants used the Ch‐LC display, young participants had significantly worse visual performance under an ambient illuminance of 50 lx compared to other illuminance settings, but elderly participants had significantly better visual performance under an ambient illuminance higher than 1500 lx. When young participants used a conventional transmissive LCD, the ambient illuminance had no significant effect on their visual performance. When elderly participants use a conventional transmissive LCD, an illuminance of 50 and 6000 lx seem to have a detrimental effect on their visual performance.     

非线性负载条件下衡量功率畸变率的方法研究

对于含非线性负荷的独立微电网,负荷对系统的冲击导致功率发生严重畸变,如何反映冲击的大小,确定畸变功率是微电网发展中亟待解决的问题。针对含脉冲负载的独立直流微电网,忽略频率畸变的影响,对非正弦条件下的有功功率及其波动量进行推导,并对如何衡量功率波动的大小进行研究。依照相关标准搭建含柴油机-整流器-脉冲负载的微电网实验平台,测得系统运行时三相电压va、vb、vc及三相电流ia、ib、ic的变化曲线,基于AKAGI H的瞬时功率理论在时域中分析其有功功率,并采用Clark变换推导有功功率的功率波动量,定义功率波动率以衡量含脉冲负载独立直流微电网功率波动的大小,为提高电能质量、储能容量的配置提供新思路。     

Dynamics of cognitive load theory: A model-based approach

Since its conception nearly two decades ago, cognitive load theory (CLT) has been a fertile ground for both empirical and theoretical investigations. The research accumulated over the years has contributed not only to the theory’s validation, but also generated new insights. These new insights helped to refine CLT, making it more precise, but also more complex. A formal (mathematical) simulation model is proposed as a new analytical tool for investigating CLT’s increasingly intricate postulates and their dynamic implications. This paper describes how the theoretical relationships between certain features of instruction and the cognitive capacities of learners can be expressed formally, and how the resulting model can help gain insights into the learning dynamics that arise from these relationships, providing a new aid for research, teaching and practice in the field of instructional design.     

A method for measuring the load imposed on the back of a sitting person

Abstract

A method for calculating the biomechanical load on the spine (at L3) and certain muscles in the back is described. It utilizes a small computer on-line to a force platform and the results are obtainable within a few seconds.

The method, which has been devised to evaluate aspects of industrial seating, deals with vertical forces arising from support of the hands and arms, weight lifting and vertical acceleration as well as trunk movements. It does not deal with horizontally imposed forces. It is shown to be quicker and more accurate than calculations using manual measurements of displacements and can be applied in both the field and the laboratory.     

Tangible displays for the masses: spatial interaction with handheld displays by using consumer depth cameras

Spatially aware handheld displays are a promising approach to interact with complex information spaces in a more natural way by extending the interaction space from the 2D surface to the 3D physical space around them. This is achieved by utilizing their spatial position and orientation for interaction purposes. Technical solutions for spatially tracked displays already exist in research laboratories, e.g., embedded in a tabletop environment. Along with a large stationary screen, such multi-display systems provide a rich design space with a variety of benefits to users, e.g., the explicit support of co-located parallel work and collaboration. As we see a great future in the underlying interaction principles, the question is how the technology can be made accessible to the public. With our work, we want to address this issue. In the long term, we envision a low-cost tangible display ecosystem that is suitable for everyday usage and supports both active displays (e.g., the iPad) and passive projection media (e.g., paper screens and everyday objects such as a mug). The two major contributions of this article are a presentation of an exciting design space and a requirement analysis regarding its technical realization with special focus on a broad adoption by the public. In addition, we present a proof of concept system that addresses one technical aspect of this ecosystem: the spatial tracking of tangible displays with a consumer depth camera (Kinect).     

Myoelectric arm using artificial neural networks to reduce cognitive load of the user

Today’s multiple degree-of-freedom myoelectric prosthesis relies only on direct control by the processed electromyographic signal. However, it is difficult for the wearer to learn unnatural muscle contractions in order to wield more than three DoFs of the arm. This makes it almost impossible to use more complex prostheses with a larger number of actuators. Methods based on sensor–actuator loop and artificial intelligence may reduce cognitive load of the user by removing low level control, and an intelligent control system would make it needless to micromanage every action. For this purpose, sensor system for body segments motion capture was developed, as well as sensor system for prosthetic limb’s environment motion capture. Neural networks were designed to process data from the sensor systems. For the identification of the knee angle, orientation trackers were used. Neural network predictor of arm positions predicts the shoulder angle using the information about movement of the lower limb. In the case of the periodic/cyclic movements of the legs, such as walking, the control unit uses typical movement patterns of the healthy upper limb. Ultrasonic range sensors are used to create 3D map of objects in the environment around the arm. Neural network predictor of object positions predicts collisions. If the potential collisions are identified, the control unit stops arm movement. The new methods were verified by MATLAB and are designed as a part of assistive technology for disabled people and are to be understood as an original contribution to the investigation of new prosthesis control units and international debate on the design of new myoelectric prostheses.

     

Visual attention in driving: the effects of cognitive load and visual disruption

OBJECTIVE: This study investigates the effect of cognitive load on guidance of visual attention. BACKGROUND: Previous studies have shown that cognitive load can undermine driving performance, particularly drivers' ability to detect safety-critical events. Cognitive load combined with the loss of exogenous cues, which can occur when the driver briefly glances away from the roadway, may be particularly detrimental. METHOD: In each of two experiments, twelve participants engaged in an auditory task while performing a change detection task. A change blindness paradigm was implemented to mask exogenous cues by periodically blanking the screen in a driving simulator while a change occurred. Performance measures included participants' sensitivity to vehicle changes and confidence in detecting them. RESULTS: Cognitive load uniformly diminished participants' sensitivity and confidence, independent of safety relevance or lack of exogenous cues. Periodic blanking, which simulated glances away from the road-way, undermined change detection to a greater degree than did cognitive load; however, drivers' confidence in their ability to detect changes was diminished more by cognitive load than by periodic blanking. CONCLUSION: Cognitive load and short glances away from the road are additive in their tendency to increase the likelihood of drivers missing safety-critical events. APPLICATION: This study demonstrates the need to consider the combined consequence of cognitive load and brief glances away from the road in the design of emerging in-vehicle devices and the need to provide drivers with better feedback regarding these consequences.     

Time identification of design knowledge push based on cognitive load measurement

The reuse of multidisciplinary design knowledge is pivotal in product development because of the increasingly fierce market competition. It can assist designers, particularly those who lack sufficient experience, in making correct decisions and achieving rapid design. Traditionally, designers primarily acquire design knowledge through information retrieval, which is typically time-consuming and inefficient. A solution that is widely considered to overcome the deficiencies of traditional knowledge retrieval approaches and actively provide designers with necessary knowledge is knowledge push. However, achieving the timely push of required knowledge to designers during the design process remains a challenging task. Accordingly, this paper presents a time identification method based on cognitive load measurement to identify the suitable time for design knowledge push. First, behavioral indicators related to the changes in cognitive load are identified by investigating the influence of the load on three types of behaviors: mouse dynamics, keystroke dynamics, and emotional states. Second, the possibility and efficacy of inferring the cognitive load by simultaneously and unobtrusively tracking the three aforementioned behaviors are considered through behavioral observations. Finally, predicting the knowledge push time based on the cognitive load using classification algorithms is investigated. The experimental results indicate that the accuracy of the proposed method in inferring the cognitive load is 55%, and that of push time is 83%.     

Investigation of perceived image quality and colourfulness in mobile displays for different cultures,ambient illumination,and resolution

This study explored the effects of culture, ambient illumination, and resolution on perceived image quality and colourfulness of mobile displays. Thirty Taiwanese and 30 American students participated in the experiment. Two types of culture (Taiwanese and American), two types of illumination level (1500 lux and 7000 lux), and five types of resolution level (320×240, 260×208, 200×160, 140×112, and 80×64) were investigated in the experiment. Interactions between culture and resolution, and between illumination and resolution, were found for both perceived image quality and colourfulness. The results indicated that subjects were able to detect smaller differences in perceived image quality but not for colourfulness, and Taiwanese subjects could detect smaller differences than could the American subjects for both perceived image quality and colourfulness. The results further indicated that Taiwanese subjects were able to detect smaller differences at most of the resolution levels for colourfulness in 1500 lux than were the American subjects.

Practitioner Summary: This study found, from culture differences and ergonomics considerations, that Taiwanese subjects could detect smaller differences than could American subjects when evaluating perceived image quality and colourfulness on mobile displays. Mobile display manufacturers can use the results of this study as a reference for future mobile display design.