NASA Task Load Index Questionnaire Research Articles

Using a Guidance Virtual Fixture on a Soft Robot to Improve Ureteroscopy Procedures in a Phantom

Manipulating a flexible ureteroscope is difficult, due to its bendable body and hand–eye coordination problems, especially when exploring the lower pole of the kidney. Though robotic interventions have been adopted in various clinical scenarios, they are rarely used in ureteroscopy. This study proposes a teleoperation system consists of a soft robotic endoscope together with a Guidance Virtual Fixture (GVF) to help users explore the kidney’s lower pole. The soft robotic arm was a cable-driven, 3D-printed design with a helicoid structure. GVF was dynamically constructed using video streams from an endoscopic camera. With a haptic controller, GVF can provide haptic feedback to guide the users in following a trajectory. In the user study, participants were asked to follow trajectories when the soft robotic arm was in a retroflex posture. The results suggest that the GVF can reduce errors in the trajectory tracking tasks when the users receive the proper training and gain more experience. Based on the NASA Task Load Index questionnaires, most participants preferred having the GVF when manipulating the robotic arm. In conclusion, the results demonstrate the benefits and potential of using a robotic arm with a GVF. More research is needed to investigate the effectiveness of the GVFs and the robotic endoscope in ureteroscopic procedures.

The role of visual conditions and aircraft type on different aspects of pilot workload

ObjectiveThe objective of our work was to assess the impact of flight conditions by aircraft type on the workload estimated using NASA-Task Load Index (NASA-TLX). BackgroundLearning about subjective workload is important for assessing the impact of a pilot's work environment on their performance in the cockpit. This is an important element of flight safety and includes the prevention of aviation accidents. MethodsThe study included 146 military pilots that fly the following aircrafts: flying fast-jet (21), fixed-wing (24), and rotary-wing (101). The NASA-TLX questionnaire was used to assess workload and pilots were asked to determine the level of workload resulting from flying under the following conditions: daytime flight (VFR), night-vision flight performed under Night Visual Flight Rules (NVFR), and night-vision flight using night-vision goggles (NVGs). ResultsThe highest level of workload was consistently attributed to flights performed under NVG conditions. NVFR conditions were rated as the most burdensome, while VFR conditions were rated as the least burdensome. Fast-jet pilots rated their mental performance and effort workload as significantly higher than pilots of other aircrafts. ConclusionPilots’ perceived workload is influenced by both flight conditions and the type of aircraft they fly. Workload knowledge is important for flight safety and should be taken into account during training and flight-task planning. ApplicationThe results of our study can be useful both in flight training and in work on the effectiveness of the human-machine interface. Awareness of one's own limitations due to the work environment can help improve flight safety.

Immersive haptic simulation for training nurses in emergency medical procedures

The use of haptic simulation for emergency procedures in nursing training presents a viable, versatile and affordable alternative to traditional mannequin environments. In this paper, an evaluation is performed in a virtual environment with a head-mounted display and haptic devices, and also with a mannequin. We focus on a chest decompression, a life-saving invasive procedure used for trauma-associated cardiopulmonary resuscitation (and other causes) that every emergency physician and/or nurse needs to master. Participants’ heart rate and blood pressure were monitored to measure their stress level. In addition, the NASA Task Load Index questionnaire was used. The results show the approved usability of the VR environment and that it provides a higher level of immersion compared to the mannequin, with no statistically significant difference in terms of cognitive load, although the use of VR is perceived as a more difficult task. We can conclude that the use of haptic-enabled virtual reality simulators has the potential to provide an experience as stressful as the real one while training in a safe and controlled environment.

Common Subjective Mental Workload Assessment Measures: Advantages and Disadvantages

Background: The amount of mental resources required to perform simultaneously a series tasks is considered as mental workload (MWL). High and Low mental workload in the workplace is usually associated with mental fatigue, decreased performance, human error, and even harmful long-term health effects. Among the various MWL assessment techniques, the outcome measures such as questionnaires are easier and more practical in workplace settings. We aimed to compare the three current commonly advocated and used questionnaires. Material and Methods: Three common different outcome measures for evaluation of the MWL are NASA Task Load Index (NASA-TLX), Subjective Workload Assessment Technique (SWAT), and the CarMen-Q workload questionnaire. Among them the NASA-TLX is well known and more popular with six subscales that are used extensively in industrial and official workplaces. SWAT is the simplest one with three dimensions. The NASA-TLX is preferable method because of its higher sensitivity, especially in low MWL conditions. The CarMen-Q questionnaire is a new questionnaire with 29 items and 4 subscales that focuses on cognitive workload and mental fatigue. Conclusion: SWAT is the simplest and less sensitive measure than the NASA-TLX and CarMen-Q questionnaires. In contrast, the NASA-TLX is widely used and more known instrument for MWL evaluation.

Assessment of Seafarers’ Mental Workload: A Study on High Speed Craft

High speed craft has become prominent in maritime industry. Sophisticated electronic navigation equipment on bridge increases mental demands of high speed craft navigator. In the present study, mental workload of high speed craft navigators has been assessed in terms of bridge navigation operations. For this purpose, the pairwise comparison of the effects of Electronic Chart Display and Information System, Automatic Radar Plotting Aid, Automatic Identification System and autopilot on mental workload and Revised NASA Task Load Index questionnaires were carried out. High speed craft navigators sorted berthing, unberthing, navigation in coastal waters, navigation in restricted waters, and navigation on open sea operations according to their mental workload levels. In addition, they indicated the factors mostly affecting mental workload and the remarkable suggestions to keep the optimum level of mental workload. As result of these findings, considerations have been made for increasing the safety of high speed craft navigation.

XR Vest: A Novel System for Demonstration-Based Learning of Safety Skills

This work investigates the design and usability of a novel eXtended Reality (XR) Vest, which combines two viewpoints for demonstration-based training (DBT). Traditional modalities for DBT, such as pre-recorded videos and live instruction, are minimally engaging and potentially hazardous resulting in low motivation and knowledge retention. To combat this, works incorporate XR technology to improve training immersiveness, safety, and engagement. When worn by a trainer, our XR Vest enables trainees to have the first-person perspective of immersive XR environments on an integrated tablet while simultaneously watching the third-person motor movements. To test the XR Vest in DBT, twenty-eight individuals completed three training sessions 1) using an Oculus Quest 2 ( baseline), 2) watching a DBT video on a desktop computer monitor (first-person perspective), and 3) viewing a DBT on the XR Vest (first-person and third-person perspectives). Following each session, the participants performed a memory aptitude test to evaluate their recall, a NASA Task Load Index questionnaire to investigate their perceived workload, and a System Usability Scale (SUS) questionnaire to measure the usability of the systems. A linear mixed-effect analysis showed significant differences between the temporal demand, physical demand, and frustration in the NASA-TLX scores and the integration and learnability features in the SUS scores. The results suggest that incorporating XR technology in first- and third-person perspectives within the XR Vest decreased workload and improved system usability. Future works should evaluate the benefits of this XR design in other domains where DBT is used.

Effortless Polite Telepresence using Intention Recognition

Telepresence technology creates the opportunity for people that were traditionally left out of the workforce to work remotely. In the service industry, a pool of novice remote workers could teleoperate robots to perform short work stints to fill in the gaps left by the dwindling workforce. A hurdle is that consistently talking appropriately and politely imposes a severe mental burden on such novice operators and the quality of the service may suffer. In this study, we propose a teleoperation support system that lets novice remote workers talk freely without considering appropriateness and politeness while maintaining the quality of the service. The proposed system exploits intent recognition to transform casual utterances into predefined appropriate and polite utterances. We conducted a within subject user study where 23 participants played the role of novice remote operators controlling a guardsman robot in charge of monitoring customers’ behaviors. We measured the workload with and without using the proposed support system using NASA task load index questionnaires. The workload was significantly lower ( p <.001) when using the proposed support system ( M = 46.07, SD = 14.36) than when not using it ( M = 62.74, SD = 12.70). The effect size was large (Cohen’s d = 1.23).

Human-machine interface for two-dimensional steering control with the auricular muscles.

Human-machine interfaces (HMIs) can be used to decode a user's motor intention to control an external device. People that suffer from motor disabilities, such as spinal cord injury, can benefit from the uses of these interfaces. While many solutions can be found in this direction, there is still room for improvement both from a decoding, hardware, and subject-motor learning perspective. Here we show, in a series of experiments with non-disabled participants, a novel decoding and training paradigm allowing naïve participants to use their auricular muscles (AM) to control two degrees of freedom with a virtual cursor. AMs are particularly interesting because they are vestigial muscles and are often preserved after neurological diseases. Our method relies on the use of surface electromyographic records and the use of contraction levels of both AMs to modulate the velocity and direction of a cursor in a two-dimensional paradigm. We used a locking mechanism to fix the current position of each axis separately to enable the user to stop the cursor at a certain location. A five-session training procedure (20-30 min per session) with a 2D center-out task was performed by five volunteers. All participants increased their success rate (Initial: 52.78 ± 5.56%; Final: 72.22 ± 6.67%; median ± median absolute deviation) and their trajectory performances throughout the training. We implemented a dual task with visual distractors to assess the mental challenge of controlling while executing another task; our results suggest that the participants could perform the task in cognitively demanding conditions (success rate of 66.67 ± 5.56%). Finally, using the Nasa Task Load Index questionnaire, we found that participants reported lower mental demand and effort in the last two sessions. To summarize, all subjects could learn to control the movement of a cursor with two degrees of freedom using their AM, with a low impact on the cognitive load. Our study is a first step in developing AM-based decoders for HMIs for people with motor disabilities, such as spinal cord injury.

Mental workload, musculoskeletal disorders, and associated factors among international transport truck drivers.

Many health changes are related to how individuals respond to work events that are influenced by organizational, physical, and human factors. We aim to evaluate the mental workload, the manifestation of musculoskeletal disorders, the associated factors, and their relationships among international transport truck drivers. This is a descriptive, cross-sectional diagnostic study of 70 truck drivers who entered the intermodal terminal of the city of Uruguaiana, state of Rio Grande do Sul, Brazil, in January 2021. Participants completed the NASA Task Load Index questionnaire and the Nordic Musculoskeletal Symptom Questionnaire, along with questions about work characteristics and health care. The results showed that most truck drivers have a high mental workload (90.0%) and have experienced musculoskeletal symptoms in the past 12 months (72.9%). In addition, this occupational group has characteristics that are predictive of health problems, as most work over 10 hours a day (61.5%). The results also show a correlation between mental workload, hours worked, and lower back injuries (p < 0.05). There is also an association between hours worked and the occurrence of musculoskeletal disorders in the neck, shoulders, and lower back in the past 12 months and in the shoulders and lower back in the past 7 days, especially for those who work over 12 hours a day. The population studied had a high mental workload and a high prevalence of musculoskeletal disorders as well as occupational characteristics predictive of harm to both physical and mental health.

Evaluation of a Vibrotactile Biofeedback System Targeting Stance Time Symmetry Ratio of Individuals With Lower-Limb Amputation: A Pilot Study

Individuals with lower-limb amputation (LLA) often exhibit atypical gait patterns and asymmetries. These patterns can be corrected using biofeedback (BFB). Real-time BFB strategies have demonstrated to be effective to various degrees in BFB systems. However, no studies have evaluated the use of corrective vibrotactile BFB strategies to improve temporal gait symmetry of LLA. The aim of this study was to evaluate a wearable vibrotactile BFB system to improve stance time symmetry ratio (STSR) of LLA, and compare two corrective BFB strategies that activate either one or two vibrating motors at two different frequency and amplitude levels, based on a pre-set STSR target. Gait patterns of five unilateral LLA were assessed with and without BFB. Spatiotemporal and kinematic gait parameters were measured and assessed using a wearable motion capture system. Usability and workload were assessed using the System Usability Scale and NASA Task Load Index questionnaires, respectively. Results showed that participants significantly (p<0.001) improved STSR with BFB; however, this coincided with a reduction in gait speed and cadence compared to walking without feedback. Knee and hip flexion angles improved and changes in other parameters were variable. Immediate post-test retention effects were observed, suggesting that gait changes due to BFB were preserved for at least a short-time after feedback was withdrawn. System usability was found to be acceptable while using BFB. The outcomes of this study provide new insights into the development and implementation of clinically practical and viable BFB systems. Future work should focus on assessing the long-term use and retention effects of BFB outside controlled-laboratory conditions.

Impact of Industry 4.0 adoption on workload demands in contact centers

AbstractThis paper examines the impact of Industry 4.0 (I4.0) technologies on employees workload in contact centers. For that, we adopted the NASA task load index questionnaire to assess the workload of 100 employees from different contact centers in India that have been adopting I4.0 technologies. The collected data is analyzed through multivariate techniques. This study is grounded on concepts from the multiple resource theory. Our findings indicate positive and negative effects of I4.0 on employees workload, conditioned on the adopted technologies (i.e., Internet‐of‐Things, cloud computing, big data, machine learning/artificial intelligence, remote monitoring, and wireless sensors) and workload dimensions considered (i.e., mental demand, physical demand, temporal demand, overall performance, effort, and frustration level). Identifying I4.0's impacts on employees workload allows planning of managerial efforts to mitigate potential issues while setting clear expectations related to the digital transformation of contact centers' processes and services.

Evaluating Changes in Mental Workload in Indoor and Outdoor Ultra-Distance Cycling.

Whilst increasing mental workload has been shown to have a detrimental effect on cycling performance and more generally to increase the risk of harm, no studies have measured how mental workload changes as a function of ultra-distance cycling, indoors or outdoors. Our objective was to measure the difference in mental workload, as indicated by changes in EEG theta power, components of HRV and psychomotor vigilance and as reported using the ‘NASA Task Load Index questionnaire’, before and after a 5 h indoor ride and outdoor ride completed at 65% of functional threshold power. Results of the NASA-TLX indicated the mental demand of outdoor cycling to be significantly less than that of indoor cycling. There were significant differences in the PVT results between the pre and the post outdoor ride average and median response times. The slowest 10% PVT responses were significantly slower pre than post the indoor ride. There were significant differences in HRV between pre and post outdoor and indoor rides, specifically, in the average RR intervals, RMSSD (ms2), LFPower (ms2), NN50. There were modest changes in indicators of mental workload during an ultra-distance cycle ride. As such, mental workload during ultra-distance cycling is unlikely to be a contributory factor to decreases in performance or to an increased likelihood of accident and injury.

WAUC: A Multi-Modal Database for Mental Workload Assessment Under Physical Activity.

Assessment of mental workload is crucial for applications that require sustained attention and where conditions such as mental fatigue and drowsiness must be avoided. Previous work that attempted to devise objective methods to model mental workload were mainly based on neurological or physiological data collected when the participants performed tasks that did not involve physical activity. While such models may be useful for scenarios that involve static operators, they may not apply in real-world situations where operators are performing tasks under varying levels of physical activity, such as those faced by first responders, firefighters, and police officers. Here, we describe WAUC, a multimodal database of mental Workload Assessment Under physical aCtivity. The study involved 48 participants who performed the NASA Revised Multi-Attribute Task Battery II under three different activity level conditions. Physical activity was manipulated by changing the speed of a stationary bike or a treadmill. During data collection, six neural and physiological modalities were recorded, namely: electroencephalography, electrocardiography, breathing rate, skin temperature, galvanic skin response, and blood volume pulse, in addition to 3-axis accelerometry. Moreover, participants were asked to answer the NASA Task Load Index questionnaire after each experimental section, as well as rate their physical fatigue level on the Borg fatigue scale. In order to bring our experimental setup closer to real-world situations, all signals were monitored using wearable, off-the-shelf devices. In this paper, we describe the adopted experimental protocol, as well as validate the subjective, neural, and physiological data collected. The WAUC database, including the raw data and features, subjective ratings, and scripts to reproduce the experiments reported herein will be made available at: http://musaelab.ca/resources/.

Covid-19 effects on the workload of Iranian healthcare workers

BackgroundIn this study, we aimed to evaluate the impact of the COVID-19 epidemic on the workload and mental health of Iranian medical staff using the General Health Questionnaire (GHQ-12) and NASA -Task Load Index (NASA-TLX) Questionnaire between March and April 2020, respectively.MethodsThe present cross-sectional study was conducted from March 5th to April 5th, 2020. To evaluate the workload and mental health of participants NASA-TLX and GHQ-12 online questionnaires were distributed. Data were entered into software SPSS (Version 23) and T-test, ANOVA, Regression methods were used for data analysis.ResultsHealth workers who encountered COVID- 19 patients, were subjected to more task load compared to those who had no contact with COVID- 19 patients at the workplace (p < 0.001). In terms of the subscale score of NASA-TLX, nurses had more scores in mental pressure, physical pressure, time pressure (temporal), and frustration compared to the other jobs (p < 0.05). Moreover, nurses had significantly more workload compared to the other jobs.ConclusionsType of job, the shift of work, educational level, and facing COVID-19 affected the score of NASA-TLX. NASA-TLX scores were higher in nursing compared to the scores of other health staff groups. The results of this study indicate that the scores of NASA-TLX and GHQ-12 among staff who had contact with COVID-19 patients were significantly higher than those who did not face COVID-19 patients. We suggested that a comprehensive assistance should be provided to support the well-being of healthcare workers especially nurses and healthcare workers who treated COVID-19 patients.

Laparoscopy with augmented reality adaptations.

One of the most promising applications of Optical See-Through Augmented Reality is minimally laparoscopic surgery, which currently suffers from problems such as surgeon discomfort and fatigue caused by looking at a display positioned outside the surgeon's visual field, made worse by the length of the procedure. This fatigue is especially felt on the surgeon's neck, as it is strained from adopting unnatural postures in order to visualise the laparoscopic video feed. Throughout this paper, we will present work in Augmented Reality, as well as developments in surgery and Augmented Reality applied to both surgery in general and laparoscopy in particular to address these issues. We applied user and task analysis methods to learn about practices performed in the operating room by observing surgeons in their working environment in order to understand, in detail, how they performed their tasks and achieved their intended goals. Drawing on observations and analysis of video recordings of laparoscopic surgeries, we identified relevant constraints and design requirements. Besides proposals to approach the ergonomic issues, we present a design and implementation of a multimodal interface to enhance the laparoscopic procedure. Our method makes it more comfortable for surgeons by allowing them to keep the laparoscopic video in their viewing area regardless of neck posture. Also, our interface makes it possible to access patient imaging data without interrupting the operation. It also makes it possible to communicate with team members through a pointing reticle. We evaluated how surgeons perceived the implemented prototype, in terms of usefulness and usability, via a think-aloud protocol to conduct qualitative evaluation sessions which we describe in detail in this paper. In addition to checking the advantages of the prototype as compared to traditional laparoscopic settings, we also conducted a System Usability Scale questionnaire for measuring its usability, and a NASA Task Load Index questionnaire to rate perceived workload and to assess the prototype effectiveness. Our results show that surgeons consider that our prototype can improve surgeon-to-surgeon communication using head pose as a means of pointing. Also, surgeons believe that our approach can afford a more comfortable posture throughout the surgery and enhance hand-eye coordination, as physicians no longer need to twist their necks to look at screens placed outside the field of operation.

Relationship between mental workload and salivary cortisol levels: A field study.

Mental workload (MW) assessment is a key point in research and development of human-machine interfaces in the workplace. This study aimed to examine the relationship between mental workload and the amount of salivary cortisol amongst technicians of an Iranian combined cycle power plant. A total of 18 technicians participated in this pilot study. First, task analysis was carried out to determine operation steps that forced us to separate them in to two groups. Next, the Visual, Auditory, Cognitive, and Psychomotor (VACP) technique and NASA Task Load Index (NASA-TLX) questionnaire were used to examine their mental workload. Then, the operator's salivary samples were collected at four specific times of both off and working days. Finally, the relationship between mental workload and salivary cortisol was examined with the analysis of Pearson correlation. The results of mental workload assessment with subjective methods showed a high level of mental workload amongst all technicians. No significant association was observed between the NASA-TLX questionnaire and VACP technique with concentration of salivary cortisol (p = 0.081). Based on the results, it can be concluded that salivary cortisol might not be an appropriate physiological method to assess mental workload, since cortisol levels are highly dependent on individuals' circadian rhythm.

Abstract 247: Development and Evaluation of Standardized Communication for In-Hospital Resuscitation

Background: Recommendations for “standardized” communication during cardiopulmonary resuscitation (CPR) events to reduce interruptions in chest compressions (CCs) are lacking. We aimed to achieve consensus on standardized communication during in-hospital CPR, evaluate feasibility and potential to decrease CC pauses, mental task load, and frustration. Methods: Modified Delphi consensus surveys of International Liaison Committee on Resuscitation taskforce members to identify preferred communication for in-hospital cardiac arrest teams. Consensus was reached after-survey teleconference resolution by a team of interdisciplinary experts in communication and CPR. Feasibility was tested in 8 simulated CPR scenarios with physician team leaders randomized (1:1) to ‘standardized’ communication vs. “usual best practice”, closed loop communication. Team leaders watched a 3-min video and received a 10-min training on the assigned intervention before the CPR scenario. NASA task load index questionnaires were used to assess mental task load and frustration (0=lowest to 100=highest). Results: Modified Delphi consensus on standardized communication included: 1) preparing the team 15-30 seconds before interrupting CCs, 2) countdown for interruption synchronized with 5 CCs, 3) action words for stopping and resuming CCs, 4) action words for intubation and defibrillation. Among 8 CPR teams (4 standardized, 4 usual communication), median (Q1; Q3) CC interruption duration for rhythm check was significantly shorter, 5.3 (4.8; 6.8) vs. 9.4 (6.4; 13.0) sec for standardized vs. closed loop communication [p=0.02]. Median (Q1; Q3) scores of mental task load were 63 (33; 70) vs 85 (70; 96), [p=0.10] and frustration 10 (5; 34) vs 40 (26; 50) [p=0.11] for standardized vs. closed loop communication. Trained team leaders adhered to standardized phrases 77% of the time. Conclusion: Expert consensus for standardized communication during in-hospital CPR was achieved. Pilot simulation implementation of standardized communication demonstrated feasibility of team leader adherence, significantly decreased duration of CC interruption during rhythm checks, and a tendency to reduce team leader task load and frustration.

Listening Effort by Native and Nonnative Listeners Due to Noise, Reverberation, and Talker Foreign Accent During English Speech Perception.

Purpose Understanding speech in complex realistic acoustic environments requires effort. In everyday listening situations, speech quality is often degraded due to adverse acoustics, such as excessive background noise level (BNL) and reverberation time (RT), or talker characteristics such as foreign accent ( Mattys, Davis, Bradlow, & Scott, 2012 ). In addition to factors affecting the quality of the input acoustic signals, listeners' individual characteristics such as language abilities can also make it more difficult and effortful to understand speech. Based on the Framework for Understanding Effortful Listening ( Pichora-Fuller et al., 2016 ), factors such as adverse acoustics, talker accent, and listener language abilities can all contribute to increasing listening effort. In this study, using both a dual-task paradigm and a self-report questionnaire, we seek to understand listening effort in a wide range of realistic classroom acoustic conditions as well as varying talker accent and listener English proficiency. Method One hundred fifteen native and nonnative adult listeners with normal hearing were tested in a dual task of speech comprehension and adaptive pursuit rotor (APR) under 15 acoustic conditions from combinations of BNLs and RTs. Listeners provided responses on the NASA Task Load Index (TLX) questionnaire immediately after completing the dual task under each acoustic condition. The NASA TLX surveyed 6 dimensions of perceived listening effort: mental demand, physical demand, temporal demand, effort, frustration, and perceived performance. Fifty-six listeners were tested with speech produced by native American English talkers; the other 59 listeners, with speech from native Mandarin Chinese talkers. Based on their 1st language learned during childhood, 3 groups of listeners were recruited: listeners who were native English speakers, native Mandarin Chinese speakers, and native speakers of other languages (e.g., Hindu, Korean, and Portuguese). Results Listening effort was measured objectively through the APR task performance and subjectively using the NASA TLX questionnaire. Performance on the APR task did not vary with changing acoustic conditions, but it did suggest increased listening effort for native listeners of other languages compared to the 2 other listener groups. From the NASA TLX, listeners reported feeling more frustrated and less successful in understanding Chinese-accented speech. Nonnative listeners reported more listening effort (i.e., physical demand, temporal demand, and effort) than native listeners in speech comprehension under adverse acoustics. When listeners' English proficiency was controlled, higher BNL was strongly related to a decrease in perceived performance, whereas such relationship with RT was much weaker. Nonnative listeners who shared the foreign talkers' accent reported no change in listening effort, whereas other listeners reported more difficulty in understanding the accented speech. Conclusions Adverse acoustics required more effortful listening as measured subjectively with a self-report NASA TLX. This subjective scale was more sensitive than a dual task that involved speech comprehension, which was beyond sentence recall. It was better at capturing the negative impacts on listening effort from acoustic factors (i.e., both BNL and RT), talker accent, and listener language abilities.

A Shaping Procedure to Modulate Two Cognitive Tasks to Improve a Sensorimotor Rhythm-Based Brain-Computer Interface System.

This study aimed to propose an adapted feedback using a psychological learning technique based on Skinner's shaping method to help the users to modulate two cognitive tasks (right-hand motor imagination and relaxed state) and improve better control in a Brain-Computer Interface. In the first experiment, a comparative study between performance in standard feedback (N = 9) and shaping method (N = 10) was conducted. The NASA Task Load Index questionnaire was applied to measure the user's workload. In the second experiment, a single case study was performed (N = 5) to verify the continuous learning by the shaping method. The first experiment showed significant interaction effect between sessions and group (F(1, 17) = 5.565; p = .031) which the shaping paradigm was applied. A second interaction effect demonstrates a higher performance increase in the relax state task with shaping procedure (F(1, 17) = 5. 038; p = .038). In NASA-TXL an interaction effect was obtained between the group and the cognitive task in Mental Demand (F(1, 17) = 6, 809; p = .018), Performance (F(1, 17) = 5, 725; p = .029), and Frustration (F(1, 17) = 9, 735; p = .006), no significance was found in Effort. In the second experiment, a trial-by-trial analysis shows an ascendant trend learning curve for the cognitive task with the lowest initial acquisition (relax state). The results suggest the effectiveness of the shaping procedure to modulate brain rhythms, improving mainly the cognitive task with greater initial difficulty and provide better interaction perception.

Face and content validity of Xperience™ Team Trainer: bed-side assistant training simulator for robotic surgery.

In robotic surgery, the coordination between the console-side surgeon and bed-side assistant is crucial, more than in standard surgery or laparoscopy where the surgical team works in close contact. Xperience™ Team Trainer (XTT) is a new optional component for the dv-Trainer® platform and simulates the patient-side working environment. We present preliminary results for face, content, and the workload imposed regarding the use of the XTT virtual reality platform for the psychomotor and communication skills training of the bed-side assistant in robot-assisted surgery. Participants were categorized into "Beginners" and "Experts". They tested a series of exercises (Pick & Place Laparoscopic Demo, Pick & Place 2 and Team Match Board 1) and completed face validity questionnaires. "Experts" assessed content validity on another questionnaire. All the participants completed a NASA Task Load Index questionnaire to assess the workload imposed by XTT. Twenty-one consenting participants were included (12 "Beginners" and 9 "Experts"). XTT was shown to possess face and content validity, as evidenced by the rankings given on the simulator's ease of use and realism parameters and on the simulator's usefulness for training. Eight out of nine "Experts" judged the visualization of metrics after the exercises useful. However, face validity has shown some weaknesses regarding interactions and instruments. Reasonable workload parameters were registered. XTT demonstrated excellent face and content validity with acceptable workload parameters. XTT could become a useful tool for robotic surgery team training.