Exploration of User's Mental State Changes during Performing Brain-Computer Interface.

Substantial developments have been established in the past few years for enhancing the performance of brain-computer interface (BCI) based on steady-state visual evoked potential (SSVEP). The past SSVEP-BCI studies utilized different target frequencies with flashing stimuli in many different applications. However, it is not easy to recognize user's mental state changes when performing the SSVEP-BCI task. What we could observe was the increasing EEG power of the target frequency from the user's visual area. BCI user's cognitive state changes, especially in mental focus state or lost-in-thought state, will affect the BCI performance in sustained usage of SSVEP. Therefore, how to differentiate BCI users' physiological state through exploring their neural activities changes while performing SSVEP is a key technology for enhancing the BCI performance. In this study, we designed a new BCI experiment which combined working memory task into the flashing targets of SSVEP task using 12 Hz or 30 Hz frequencies. Through exploring the EEG activity changes corresponding to the working memory and SSVEP task performance, we can recognize if the user's cognitive state is in mental focus or lost-in-thought. Experiment results show that the delta (1-4 Hz), theta (4-7 Hz), and beta (13-30 Hz) EEG activities increased more in mental focus than in lost-in-thought state at the frontal lobe. In addition, the powers of the delta (1-4 Hz), alpha (8-12 Hz), and beta (13-30 Hz) bands increased more in mental focus in comparison with the lost-in-thought state at the occipital lobe. In addition, the average classification performance across subjects for the KNN and the Bayesian network classifiers were observed as 77% to 80%. These results show how mental state changes affect the performance of BCI users. In this work, we developed a new scenario to recognize the user's cognitive state during performing BCI tasks. These findings can be used as the novel neural markers in future BCI developments.

"Working on Wellness:" protocol for a worksite health promotion capacity-building program for employers.

BACKGROUND: In the United States, worksite wellness programs are more often offered by larger employers. The Massachusetts Working on Wellness (WoW) program is an innovative, statewide capacity-building model designed to increase the number of smaller employers (200 or fewer workers) adopting health promotion initiatives. This article describes the WoW program design and approaches to recruitment, implementation, and evaluation. METHODS/DESIGN: WoW provides employer training, technical assistance and seed funding, utilizing a Wellness Program Development framework based on recognized good practices. For-profit employers with 200 employees or fewer are eligible for and encouraged to apply for a Massachusetts Small Business Wellness Tax Credit. During the phase described in this paper, employer organizations applied to the program and committed to designating a champion responsible for program implementation. Interventions were to include policy and environmental supports, as well as those targeting individual behavior change through raising awareness and education. Supports provided to employers included seed grants for qualifying activities (up to $10,000 with matching required), community linkages, data collection and organization-specific feedback tools, an on-line curriculum supplemented with technical assistance, and an expert webinar series. Data collection at multiple time points, from the initial application through program completion, provides information for evaluation of recruitment, planned and completed activities. DISCUSSION: This model is grounded in literature on good practices as well as in local knowledge about Massachusetts employers. It does not directly address the influence of working conditions, which can affect both worker participation and health behaviors. Implementation may be less successful with some organizations, such as those with many workers who are part-time or geographically distributed rather than in a centralized physical location. Program evaluation will assess the extent to which WoW achieves its goals. The data are expected to increase understanding of the needs of smaller employers and industries not traditionally implementing employee wellness programs.

Frequent Emergency Department Visits and Hospitalizations Among Homeless People With Medicaid: Implications for Medicaid Expansion.

OBJECTIVES: We examined factors associated with frequent hospitalizations and emergency department (ED) visits among Medicaid members who were homeless. METHODS: We included 6494 Massachusetts Medicaid members who received services from a health care for the homeless program in 2010. We used negative binomial regression to examine variables associated with frequent utilization. RESULTS: Approximately one third of the study population had at least 1 hospitalization and two thirds had 1 or more ED visits. More than 70% of hospitalizations and ED visits were incurred by only 12% and 21% of these members, respectively. Homeless individuals with co-occurring mental illness and substance use disorders were at greatest risk for frequent hospitalizations and ED visits (e.g., incidence rate ratios [IRRs] = 2.9-13.8 for hospitalizations). Individuals living on the streets also had significantly higher utilization (IRR = 1.5). CONCLUSIONS: Despite having insurance coverage, homeless Medicaid members experienced frequent hospitalizations and ED visits. States could consider provisions under the Patient Protection and Affordable Care Act (e.g., Medicaid expansion and Health Homes) jointly with housing programs to meet the needs of homeless individuals, which may improve the quality and cost effectiveness of care.

KGScope: Interactive Visual Exploration of Knowledge Graphs with Embedding-based Guidance.

Knowledge graphs have been commonly used to represent relationships between entities and utilized in the industry to enhance service qualities. As knowledge graphs integrate data from a variety of sources, they can also be useful references for data analysts. However, there is a lack of effective tools to make the most of the rich information in knowledge graphs. Existing knowledge graph exploration systems are ineffective because they didn?t consider various users? needs and the characteristics of knowledge graphs. Exploratory approaches specifically designed for uncovering and summarizing insights in knowledge graphs have not been well studied yet. In this paper, we propose KGScope that supports interactive visual explorations and provides embedding-based guidance to derive insights from knowledge graphs. We demonstrate KGScope with usage scenarios and assess its efficacy in supporting knowledge graph exploration with a user study. The results show that KGScope supports knowledge graph exploration effectively by providing useful information and aiding comprehensive exploration.

Investigating the Effects of Avatarization and Interaction Techniques on Near-field Mixed Reality Interactions with Physical Components.

Mixed reality (MR) interactions feature users interacting with a combination of virtual and physical components. Inspired by research investigating aspects associated with near-field interactions in augmented and virtual reality (AR & VR), we investigated how avatarization, the physicality of the interacting components, and the interaction technique used to manipulate a virtual object affected performance and perceptions of user experience in a mixed reality fundamentals of laparoscopic peg-transfer task wherein users had to transfer a virtual ring from one peg to another for a number of trials. We employed a 3 (Physicality of pegs) X 3 (Augmented Avatar Representation) X 2 (Interaction Technique) multi-factorial design, manipulating the physicality of the pegs as a between-subjects factor, the type of augmented self-avatar representation, and the type of interaction technique used for object-manipulation as within-subjects factors. Results indicated that users were significantly more accurate when the pegs were virtual rather than physical because of the increased salience of the task-relevant visual information. From an avatar perspective, providing users with a reach envelope-extending representation, though useful, was found to worsen performance, while co-located avatarization significantly improved performance. Choosing an interaction technique to manipulate objects depends on whether accuracy or efficiency is a priority. Finally, the relationship between the avatar representation and interaction technique dictates just how usable mixed reality interactions are deemed to be.

The Effects of Secondary Task Demands on Cybersickness in Active Exploration Virtual Reality Experiences.

Active exploration in virtual reality (VR) involves users navigating immersive virtual environments, going from one place to another. While navigating, users often engage in secondary tasks that require attentional resources, as in the case of distracted driving. Inspired by research generally studying the effects of task demands on cybersickness (CS), we investigated how the attentional demands specifically associated with secondary tasks performed during exploration affect CS. Downstream of this, we studied how increased attentional demands from secondary tasks affect spatial memory and navigational performance. We discuss the results of a multi-factorial between-subjects study, manipulating a secondary task's demand across two levels and studying its effects on CS in two different sickness-inducing levels of an exploration experience. The secondary task's demand was manipulated by parametrically varying $n$ in an aural $n$-back working memory task and the provocativeness of the experience was manipulated by varying how frequently users experienced a yaw-rotational reorientation effect during the exploration. Results revealed that increases in the secondary task's demand increased sickness levels, also resulting in a higher temporal onset rate, especially when the experience was not already highly sickening. Increased attentional demand from the secondary task also vitiated navigational performance and spatial memory. Overall, increased demands from secondary tasks performed during navigation produce deleterious effects on the VR experience.

Health care utilization patterns of homeless individuals in Boston: preparing for Medicaid expansion under the Affordable Care Act.

OBJECTIVES: We studied 6494 Boston Health Care for the Homeless Program (BHCHP) patients to understand the disease burden and health care utilization patterns for a group of insured homeless individuals. METHODS: We studied merged BHCHP data and MassHealth eligibility, claims, and encounter data from 2010. MassHealth claims and encounter data provided a comprehensive history of health care utilization and expenditures, as well as associated diagnoses, in both general medical and behavioral health services sectors and across a broad range of health care settings. RESULTS: The burden of disease was high, with the majority of patients experiencing mental illness, substance use disorders, and a number of medical diseases. Hospitalization and emergency room use were frequent and total expenditures were 3.8 times the rate of an average Medicaid recipient. CONCLUSIONS: The Affordable Care Act provides a framework for reforming the health care system to improve the coordination of care and outcomes for vulnerable populations. However, improved health care coverage alone may not be enough. Health care must be integrated with other resources to address the complex challenges presented by inadequate housing, hunger, and unsafe environments.

The Effects of Auditory, Visual, and Cognitive Distractions on Cybersickness in Virtual Reality.

Cybersickness (CS) is one of the challenges that has hindered the widespread adoption of Virtual Reality (VR). Consequently, researchers continue to explore novel means to mitigate the undesirable effects associated with this affliction, one that may require a combination of remedies as opposed to a solitary stratagem. Inspired by research probing into the use of distractions as a means to control pain, we investigated the efficacy of this countermeasure against CS, studying how the introduction of temporally time-gated distractions affects this malady during a virtual experience featuring active exploration. Downstream of this, we discuss how other aspects of the VR experience are affected by this intervention. We discuss the results of a between-subjects study manipulating the presence, sensory modality, and nature of periodic and short-lived (5-12 seconds) distractor stimuli across 4 experimental conditions: (1) no-distractors (ND); (2) auditory distractors (AD); (3) visual distractors (VD); (4) cognitive distractors (CD). Two of these conditions (VD and AD) formed a yoked control design wherein every matched pair of 'seers' and 'hearers' was periodically exposed to distractors that were identical in terms of content, temporality, duration, and sequence. In the CD condition, each participant had to periodically perform a 2-back working memory task, the duration and temporality of which was matched to distractors presented in each matched pair of the yoked conditions. These three conditions were compared to a baseline control group featuring no distractions. Results indicated that the reported sickness levels were lower in all three distraction groups in comparison to the control group. The intervention was also able to both increase the amount of time users were able to endure the VR simulation, as well as avoid causing detriments to spatial memory and virtual travel efficiency. Overall, it appears that it may be possible to make users less consciously aware and bothered by the symptoms of CS, thereby reducing its perceived severity.

How Virtual Hand Representations Affect the Perceptions of Dynamic Affordances in Virtual Reality.

User representations are critical to the virtual experience, and involve both the input device used to support interactions as well as how the user is virtually represented in the scene. Inspired by previous work that has shown effects of user representations on the perceptions of relatively static affordances, we attempt to investigate how end-effector representations affect the perceptions of affordances that dynamically change over time. Towards this end, we empirically evaluated how different virtual hand representations affect users' perceptions of dynamic affordances in an object retrieval task wherein users were tasked with retrieving a target from a box for a number of trials while avoiding collisions with its moving doors. We employed a 3 (virtual end-effector representation) X 13 (frequency of moving doors) X 2 (target object size) multi-factorial design, manipulating the input modality and its concomitant virtual end-effector representation as a between-subjects factor across three experimental conditions: (1) Controller (using a controller represented as a virtual controller); (2) Controller-hand (using a controller represented as a virtual hand); (3) Glove (using a hand tracked hi-fidelity glove represented as a virtual hand). Results indicated that the controller-hand condition produced lower levels of performance than both the other conditions. Furthermore, users in this condition exhibited a diminished ability to calibrate their performance over trials. Overall, we find that representing the end-effector as a hand tends to increase embodiment but can also come at the cost of performance, or an increased workload due to a discordant mapping between the virtual representation and the input modality used. It follows that VR system designers should carefully consider the priorities and target requirements of the application being developed when choosing the type of end-effector representation for users to embody in immersive virtual experiences.

Give Me a Hand: Improving the Effectiveness of Near-field Augmented Reality Interactions By Avatarizing Users' End Effectors.

Inspired by previous works showing promise for AR self-avatarization - providing users with an augmented self avatar, we investigated whether avatarizing users' end-effectors (hands) improved their interaction performance on a near-field, obstacle avoidance, object retrieval task wherein users were tasked with retrieving a target object from a field of non-target obstacles for a number of trials. We employed a 3 (Augmented hand representation) X 2 (density of obstacles) X 2 (size of obstacles) X 2 (virtual light intensity) multi-factorial design, manipulating the presence/absence and anthropomorphic fidelity of augmented self-avatars overlaid on the user's real hands, as a between subjects factor across three experimental conditions: (1) No-Augmented Avatar (using only real hands); (2) Iconic-Augmented Avatar; (3) Realistic Augmented Avatar. Results indicated that self-avatarization improved interaction performance and was perceived as more usable regardless of the anthropomorphic fidelity of avatar. We also found that the virtual light intensity used in illuminating holograms affects how visible one's real hands are. Overall, our findings seem to indicate that interaction performance may improve when users are provided with a visual representation of the AR system's interacting layer in the form of an augmented self-avatar.

The effect of a telephone-based health coaching disease management program on Medicaid members with chronic conditions.

BACKGROUND: Despite the growing popularity of disease management programs for chronic conditions, evidence regarding the effect of these programs has been mixed. In addition, few peer-reviewed studies have examined the effect of these programs on publicly insured populations. OBJECTIVES: To examine the effect of a telephone-based health coaching disease management program on healthcare utilization and expenditures in Medicaid members with chronic conditions. RESEARCH DESIGN: Using a difference-in-differences analysis, we examined changes in hospitalizations, emergency department (ED) visits, ambulatory care visits, and Medicaid expenditures among program members for 1 year before and 2 years after their enrollment compared with a matched comparison group. SUBJECTS: Medicaid members aged 18 to 64 with a diagnosis of qualifying chronic conditions and 2 acute health service events of hospitalizations and/or ED visits within a 12-month period. RESULTS: Changes in acute hospitalizations, ambulatory care visits, and Medicaid expenditures before and after program enrollment were similar between the 2 study groups. However, during the second year after enrollment, program members had a significantly smaller decrease in ED visits than the comparisons (8% in program members and 23% in comparisons, P value=0.03). CONCLUSIONS: Compared with a matched comparison group, the telephone-based health coaching disease management program did not demonstrate significant effects on healthcare utilization and expenditures in Medicaid members with chronic conditions.

Twelve-month diagnosed prevalence of behavioral health disorders among elderly medicare and medicaid members.

OBJECTIVES: We examined the 12-month diagnosed prevalence of behavioral health disorders (BHDs) and dementia among elderly Medicare and Medicaid members in Massachusetts by primary payment source group (dual eligible, Medicare only, and Medicaid only) and age group (65-74 years, 75-84 years, and 85 years and older). DESIGN: A retrospective cross-sectional study. SETTING: Medicare and Medicaid programs. PARTICIPANTS: Massachusetts Medicare or Medicaid enrollees age 65 and older as of January 1, 2005, (N = 679,182). MEASUREMENTS: International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes recorded on Medicare and Medicaid claims were used to identify the BHDs. RESULTS: The 12-month diagnosed prevalence was 19.4% for any BHD and 11.2% for dementia. The most common BHDs by disease category were major depression (severe mental illness [SMI]), other depression (other mental illness [OMI]), and alcohol abuse or dependence (subtance use disorder [SUD]). Dual eligibles had a considerably higher diagnosed prevalence of any BHD (38.8%), compared with 16.1% in the Medicare only group. The 12-month diagnosed prevalence of SMI, OMI, and dementia was higher in the older-age groups. Co-occurring SUD was higher for younger dual eligibiles. Dementia and mental illness co-occurred at much higher rates for dual eligibles than for either of the single-insurance groups. This combination increased with age in all three groups. CONCLUSIONS: The 12-month prevalence of BHDs and dementia among elderly dual eligibles was disproportionately higher than other elderly Medicare or Medicaid members. However, access barriers to behavioral health services for this vulnerable population could be significant because Medicare and Medicaid payment limitations resulted in financial disincentives for providing these services.

Real-time physics-based 3D biped character animation using an inverted pendulum model.

We present a physics-based approach to generate 3D biped character animation that can react to dynamical environments in real time. Our approach utilizes an inverted pendulum model to online adjust the desired motion trajectory from the input motion capture data. This online adjustment produces a physically plausible motion trajectory adapted to dynamic environments, which is then used as the desired motion for the motion controllers to track in dynamics simulation. Rather than using Proportional-Derivative controllers whose parameters usually cannot be easily set, our motion tracking adopts a velocity-driven method which computes joint torques based on the desired joint angular velocities. Physically correct full-body motion of the 3D character is computed in dynamics simulation using the computed torques and dynamical model of the character. Our experiments demonstrate that tracking motion capture data with real-time response animation can be achieved easily. In addition, physically plausible motion style editing, automatic motion transition, and motion adaptation to different limb sizes can also be generated without difficulty.

Automated recognition system to classify subcellular protein localizations in images of different cell lines acquired by different imaging systems.

Systemic analysis of subcellular protein localization (location proteomics) provides clues for understanding gene functions and physiological condition of the cells. However, recognition of cell images of subcellular structures highly depends on experience and becomes the rate-limiting step when classifying subcellular protein localization. Several research groups have extracted specific numerical features for the recognition of subcellular protein localization, but these recognition systems are restricted to images of single particular cell line acquired by one specific imaging system and not applied to recognize a range of cell image sources. In this study, we establish a single system for automated subcellular structure recognition to identify cell images from various sources. Two different sources of cell images, 317 Vero (http://gfp-cdna.embl.de) and 875 CHO cell images of subcellular structures, were used to train and test the system. When the system was trained by a single source of images, the recognition rate is high and specific to the trained source. The system trained by the CHO cell images gave high average recognition accuracy for CHO cells of 96%, but this was reduced to 46% with Vero images. When we trained the system using a mixture of CHO and Vero cell images, an average accuracy of recognition reached 86.6% for both CHO and Vero cell images. The system can reject images with low confidence and identify the cell images correctly recognized to avoid manual reconfirmation. In summary, we have established a single system that can recognize subcellular protein localizations from two different sources for location-proteomic studies. studies.

Stylized rendering using samples of a painted image.

We introduce a novel technique to generate painterly art map (PAM) for 3D non-photorealistic rendering. Our technique can automatically transfer brush stroke textures and color changes to 3D models from samples of a painted image. Therefore, the generation of stylized images/animation in the style of a given artwork can be achieved. This new approach works particularly well for a rich variety of brush strokes ranging from simple 1D and 2D line-art strokes to very complicated ones with significant variations in stroke characteristics. During the rendering/animation process, the coherence of brush stroke textures and color changes over 3D surfaces can be well maintained. With PAM, we can also easily generate the illusion of flow animation over a 3D surface to convey the shape of a model.

Geometric and Textural Blending for 3D Model Stylization.

Stylizing a 3D model with characteristic shapes or appearances is common in product design, particularly in the design of 3D model merchandise, such as souvenirs, toys, furniture, and stylized items. A model stylization approach is proposed in this study. The approach combines base and style models while preserving user-specified shape features of the base model and the attractive features of the style model with limited assistance from a user. The two models are first combined at the topological level. A tree-growing technique is utilized to search for all possible combinations of the two models. Second, the models are combined at textural and geometric levels by employing a morphing technique. Results show that the proposed approach generates various appealing models and allows users to control the diversity of the output models and adjust the blending degree between the base and style models. The results of this work are also experimentally compared with those of a recent work through a user study. The comparison indicates that our results are more appealing, feature-preserving, and reasonable than those of the compared previous study. The proposed system allows product designers to easily explore design possibilities and assists novice users in creating their own stylized models.

A lattice-based MRF model for dynamic near-regular texture tracking.

A near-regular texture (NRT) is a geometric and photometric deformation from its regular origin--a congruent wallpaper pattern formed by 2D translations of a single tile. A dynamic NRT is an NRT under motion. Although NRTs are pervasive in man-made and natural environments, effective computational algorithms for NRTs are few. This paper addresses specific computational challenges in modeling and tracking dynamic NRTs, including ambiguous correspondences, occlusions, and drastic illumination and appearance variations. We propose a lattice-based Markov-Random-Field (MRF) model for dynamic NRTs in a 3D spatiotemporal space. Our model consists of a global lattice structure that characterizes the topological constraint among multiple textons and an image observation model that handles local geometry and appearance variations. Based on the proposed MRF model, we develop a tracking algorithm that utilizes belief propagation and particle filtering to effectively handle the special challenges of the dynamic NRT tracking without any assumption on the motion types or lighting conditions. We provide quantitative evaluations of the proposed method against existing tracking algorithms and demonstrate its applications in video editing.

Cost of health care utilization among homeless frequent emergency department users.

Research demonstrates that homelessness is associated with frequent use of emergency department (ED) services, yet prior studies have not adequately examined the relationship between frequent ED use and utilization of non-ED health care services among those experiencing homelessness. There has also been little effort to assess heterogeneity among homeless individuals who make frequent use of ED services. To address these gaps, the present study used Medicaid claims data from 2010 to estimate the association between the number of ED visits and non-ED health care costs for a cohort of 6,338 Boston Health Care for the Homeless Program patients, and to identify distinct subgroups of persons in this cohort who made frequent use of ED services based on their clinical and demographic characteristics. A series of gamma regression models found more frequent ED use to be associated with higher non-ED costs, even after adjusting for demographic and clinical characteristics. Latent class analysis was used to examine heterogeneity among frequent ED users, and the results identified 6 characteristically distinct subgroups among these persons. The subgroup of persons with trimorbid illness had non-ED costs that far exceeded members of all 5 other subgroups. Study findings reinforce the connection between frequent ED use and high health care costs among homeless individuals and suggest that different groups of homeless frequent ED users may benefit from interventions that vary in terms of their composition and intensity. (PsycINFO Database Record

Changes in the use of postacute care during the initial Medicare payment reforms.

OBJECTIVE: To examine changes in postacute care (PAC) use during the initial Medicare payment reforms enacted by the Balanced Budget Act of 1997. DATA SOURCES: We used claims data from the 5 percent Medicare beneficiary sample in 1996, 1998, and 2000. Linked data from the Denominator file, Provider of Service file, and Area Resource File provided additional patient, hospital, and market-area characteristics. STUDY DESIGN: Six disease groups with high PAC use were selected for analysis. We used multinomial logit regression to examine how PAC use differed by year of service, controlling for patient, hospital, and market-area characteristics. PRINCIPAL FINDINGS: There were major changes in PAC use, and a portion of services shifted to settings where reimbursement remained cost-based. During the first reform, the home health agency interim payment system, home health use decreased consistently across disease groups. This decrease was accompanied by increased use in skilled nursing facilities (SNFs). Following the implementation of the prospective payment system for SNFs, the use of inpatient rehabilitation facilities increased. CONCLUSIONS: The shift in usage among settings occurred in two stages that corresponded to the timing of payment reforms for home health agencies and SNFs. Evidence strongly suggests the substitutability between PAC settings. Financial incentives, in addition to clinical needs and individual preferences, play a major role in PAC use.