Holocue: A Wearable Holographic Cueing Application for Alleviating Freezing of Gait in Parkinson's Disease

External visual cueing is a well-known means to target freezing of gait (FOG) in Parkinson's disease patients. Holocue is a wearable visual cueing application that allows the HoloLens 1 mixed-reality headset to present on-demand patient-tailored action-relevant 2D and 3D holographic visual cues in free-living environments. The aim of this study involving 24 Parkinson's disease patients with dopaminergic “ON state” FOG was two-fold. First, to explore unfamiliarity and habituation effects associated with wearing the HoloLens on FOG. Second, to evaluate the potential immediate effect of Holocue on alleviating FOG in the home environment. Three sessions were conducted to examine (1) the effect of wearing the unfamiliar HoloLens on FOG by comparing walking with and without the HoloLens, (2) habituation effects to wearing the HoloLens by comparing FOG while walking with HoloLens over sessions, and (3) the potential immediate effect of Holocue on FOG by comparing walking with HoloLens with and without Holocue. Wearing the HoloLens (without Holocue) did significantly increase the number and duration of FOG episodes, but this unfamiliarity effect disappeared with habituation over sessions. This not only emphasizes the need for sufficient habituation to unfamiliar devices, but also testifies to the need for research designs with appropriate control conditions when examining effects of unfamiliar wearable cueing devices. Holocue had overall no immediate effect on FOG, although objective and subjective benefits were observed for some individuals, most notably those with long and/or many FOG episodes. Our participants raised valuable opportunities to improve Holocue and confirmed our assumptions about current and anticipated future design choices, which supports ongoing Holocue development for and with end users.

Touchscreen-based finger tapping: Repeatability and configuration effects on tapping performance

Parkinson’s disease (PD) is a progressive neurodegenerative disease that affects almost 2% of the population above the age of 65. To better quantify the effects of new medications, fast and objective methods are needed. Touchscreen-based tapping tasks are simple yet effective tools for quantifying drug effects on PD-related motor symptoms, especially bradykinesia. However, there is no consensus on the optimal task set-up. The present study compares four tapping tasks in 14 healthy participants. In alternate finger tapping (AFT), tapping occurred with the index and middle finger with 2.5 cm between targets, whereas in alternate side tapping (AST) the index finger with 20 cm between targets was used. Both configurations were tested with or without the presence of a visual cue. Moreover, for each tapping task, within- and between-day repeatability and (potential) sensitivity of the calculated parameters were assessed. Visual cueing reduced tapping speed and rhythm, and improved accuracy. This effect was most pronounced for AST. On average, AST had a lower tapping speed with impaired accuracy and improved rhythm compared to AFT. Of all parameters, the total number of taps and mean spatial error had the highest repeatability and sensitivity. The findings suggest against the use of visual cueing because it is crucial that parameters can vary freely to accurately capture medication effects. The choice for AFT or AST depends on the research question, as these tasks assess different aspects of movement. These results encourage further validation of non-cued AFT and AST in PD patients.

The Effect of Transcranial Direct Current Stimulation Combined with Visual Cueing Training on Motor Function, Balance, and Gait Ability of Patients with Parkinson’s Disease

Background and Objectives: The purpose of this study was to investigate the effects of transcranial direct current stimulation (tDCS) on motor function, balance and gait ability in patients with Parkinson’s disease (PD). Materials and Methods: For the experiment, 30 patients with PD were randomly assigned to the experimental group (n = 15) and the control group (n = 15). Visual cueing training was commonly applied to both groups, the experimental group applied tDCS simultaneously with visual training, and the control group applied sham tDCS simultaneously with visual training. All subjects were pre-tested before the first intervention, post-tested after completing all 4 weeks of intervention, and followed-up tested 2 weeks after the completing intervention. The tests used the Unified Parkinson’s Disease Rating Scale (UPDRS) for motor function assessment, Functional Gait Assessment (FGA) for balance assessment, Freezing of Gait Questionnaire (FOG-Q) and the GAITRite system for gait ability assessment. Among the data obtained through the GAITRite system, gait velocity, cadence, step time, double support time, and stride length were analyzed. Results: The experimental group showed a significant decrease in UPDRS and a significant increase in FGA and cadence after the intervention. In addition, UPDRS and cadence showed a significant difference in the follow-up test compared to the pre-intervention test. Conclusions: This study suggests that the application of tDCS to the supplementary motor area of PD patients is useful as an adjuvant therapy for rehabilitation training of PD patients.

Considering visual cueing and practice type for software training’s optimisation: a study of domain experts

Purpose Software training is a new trend in software applications. A key problem with software training is that video tutorials are developed without considering the target audience. Although video tutorials are popular, little attention is given to their design features. This study aims to investigate how two multimedia research principles, visual cueing (VC) and practice type, influence task performance, mental effort and motivation. Design/methodology/approach Three video tutorials on non-linear editing were viewed by 118 Computer Science undergraduate students with high information communication technology experience. To analyse the relationships between the research variables, a 2 (non-VC versus VC) × 2 (post-video viewing practice versus stepwise viewing-based practice (SVBP) mixed factorial design was used. Findings The results indicated that neither VC nor SVBP influenced task performance; however, both practice type conditions led to higher levels of motivation. Research limitations/implications The incorporation of VC and practice type in complex software training is less likely to be beneficial for domain experts. Future studies should record eye tracking data to capture learners’ behaviours whilst learning a software application. Moreover, practice targeted with immediate feedback should be incorporated as it enhances scaffolding. Practical implications Neither practice type was considered effective by experts. A practice strategy with user-controlled pausing (i.e. markers) could enhance retention by allowing users to practice tasks after locating the most relevant parts of the video tutorial. Originality/value This study contributes to the literature by investigating two guidelines: VC and practice type in the context of complex software training targeting domain experts.

Neural responses to natural visual motion are spatially selective across the visual field, with selectivity differing across brain areas and task

It is well established that neural responses to visual stimuli are enhanced at select locations in the visual field. While spatial selectivity and the effects of spatial attention are well-understood for discrete tasks (e.g., visual cueing paradigms), little is known about neural response during a naturalistic visual experience that involves complex dynamic visual stimuli, for instance, driving. In this study, we assess the strength of neural responses across the visual space during a kart race video game. Specifically, we measure the correlation strength of scalp evoked potentials with optical flow magnitude at individual locations on the screen. We find the strongest neural responses for task-relevant locations in visual space, selectively extending to areas beyond the focus of overt attention: while the driver’s gaze is directed upon the heading direction at the center of the screen, we observe robust neural evoked responses also to peripheral areas such as the road and surrounding buildings. Importantly, this spatial selectivity of neural responses differs across scalp locations. Moreover, during active gameplay, the strength of the spatially-selective neural responses are enhanced compared to passive viewing. Spatially selective neural gains have previously been interpreted as an attentional gain mechanism. In this view, the present data suggest that different brain areas focus attention on different task-relevant portions of the visual field, reaching beyond the focus of overt attention.

3D visual cueing shortens the double support phase of the gait cycle in patients with advanced Parkinson's disease treated with DBS of the STN

Background Gait disturbances have emerged as some of the main therapeutic concerns in late-stage Parkinson’s disease (PD) treated with dopaminergic therapy and deep brain stimulation (DBS). External cues may help to overcome freezing of gait (FOG) and improve some of the gait parameters. Aim To evaluate the effect of 3D visual cues and STN-DBS on gait in PD group. Methods We enrolled 35 PD patients treated with DBS of nucleus subthalamicus (STN-DBS). Twenty-five patients (5 females; mean age 58.9 ±6.3) and 25 sex- and age-matched controls completed the gait examination. The gait in 10 patients deteriorated in OFF state. The severity of PD was evaluated using the Unified Parkinson's Disease Rating Scale (UPDRS) and Hoehn and Yahr (HY). The PD group filled the Falls Efficacy Scale-International (FES) and Freezing of Gait Questionnaire (FOGQ). Gait was examined using the GaitRite Analysis System, placed in the middle of the 10m marked path. The PD group was tested without dopaminergic medication with and without visual cueing together with the DBS switched ON and OFF. The setting of DBS was double-blind and performed in random order. Results The UPDRS was 21.9 ±9.5 in DBS ON state and 41.3 ±13.7 in DBS OFF state. HY was 2.5 ±0.6, FES 12.4 ±4.1 and FOGQ 9.4 ±5.7. In the DBS OFF state, PD group walked more slowly with shorter steps, had greater step length variability and longer duration of the double support phase compared to healthy controls. The walking speed and step length increased in the DBS ON state. The double support phase was reduced with 3D visual cueing and DBS; the combination of both cueing and DBS was even more effective. Conclusion Cueing with 3D visual stimuli shortens the double support phase in PD patients treated with DBS-STN. The DBS is more effective in prolonging step length and increasing gait speed. We conclude that 3D visual cueing can improve walking in patients with DBS.