Probability maps for deep learning-based head and neck tumor segmentation: Graphical User Interface design and test.

BACKGROUND: The different tumor appearance of head and neck cancer across imaging modalities, scanners, and acquisition parameters accounts for the highly subjective nature of the manual tumor segmentation task. The variability of the manual contours is one of the causes of the lack of generalizability and the suboptimal performance of deep learning (DL) based tumor auto-segmentation models. Therefore, a DL-based method was developed that outputs predicted tumor probabilities for each PET-CT voxel in the form of a probability map instead of one fixed contour. The aim of this study was to show that DL-generated probability maps for tumor segmentation are clinically relevant, intuitive, and a more suitable solution to assist radiation oncologists in gross tumor volume segmentation on PET-CT images of head and neck cancer patients. METHOD: A graphical user interface (GUI) was designed, and a prototype was developed to allow the user to interact with tumor probability maps. Furthermore, a user study was conducted where nine experts in tumor delineation interacted with the interface prototype and its functionality. The participants' experience was assessed qualitatively and quantitatively. RESULTS: The interviews with radiation oncologists revealed their preference for using a rainbow colormap to visualize tumor probability maps during contouring, which they found intuitive. They also appreciated the slider feature, which facilitated interaction by allowing the selection of threshold values to create single contours for editing and use as a starting point. Feedback on the prototype highlighted its excellent usability and positive integration into clinical workflows. CONCLUSIONS: This study shows that DL-generated tumor probability maps are explainable, transparent, intuitive and a better alternative to the single output of tumor segmentation models.

Impact of fatigue in surgeons on performance and patient outcome: systematic review.

BACKGROUND: While fatigue is an inevitable aspect of performing surgical procedures, lack of consensus remains on its effect on surgical performance. The aim of this systematic review was to assess the effect of non-muscular fatigue on surgical outcome. METHODS: MEDLINE and Embase were searched up to 17 January 2023. Studies on students, learning, duty-hour restrictions, muscle fatigue, non-surgical or subjective outcome, the weekend effect, or time of admission were excluded. Studies were categorized based on real-life or simulated surgery. The Cochrane risk-of-bias tool was used to assess RCTs and the Newcastle-Ottawa scale was used to assess cohort studies. Due to heterogeneity among studies, data pooling was not feasible and study findings were synthesized narratively. RESULTS: From the 7251 studies identified, 134 studies (including 1 684 073 cases) were selected for analysis (110 real-life studies and 24 simulator studies). Of the simulator studies, 46% (11 studies) reported a deterioration in surgical outcome when fatigue was present, using direct measures of fatigue. In contrast, only 35.5% (39 studies) of real-life studies showed a deterioration, observed in only 12.5% of all outcome measures, specifically involving aggregated surgical outcomes. CONCLUSION: Almost half of simulator studies, along with one-third of real-life studies, consistently report negative effects of fatigue, highlighting a significant concern. The discrepancy between simulator/real-life studies may be explained by heightened motivation and effort investment in real-life studies. Currently, published fatigue and outcome measures, especially in real-life studies, are insufficient to fully define the impact of fatigue on surgical outcomes due to the absence of direct fatigue measures and crude, post-hoc outcome measures.

At some point, surgeons become tired, just like anyone else. While in other jobs, people start to perform worse as they get tired, it is not known whether this is also true for surgeons. It is important to know this because patients may be worse off if their surgeon is tired. The aim of this study was to find out if being tired affects how surgeons do their work. Medical databases were searched through for studies on tired surgeons and the impact of fatigue on their work. Some studies looked at tired surgeons during real surgery and other studies looked at tired surgeons during sessions on surgery simulators. More than 7000 studies were examined and 134 of them were selected. They included over 1.6 million surgeries. Among these studies, 110 investigated real surgeries and 24 looked at simulated surgical sessions. Interestingly, almost half of the studies looking at simulated surgeries found that being tired had a negative effect on the simulated surgery. However, in real surgeries, this happened in only one-third of studies. The difference between real surgery and simulator surgery could be because in real surgeries surgeons always try to do their best, even when fatigued, because they are dealing with real patients. Another reason could be that the tools used to check whether surgeons are tired or whether the surgery went well are not very good. To help both surgeons and patients, there is a need to find better ways to determine if surgeons are truly tired and to make sure the tests are better.

Visuo-motor transformations in the intraparietal sulcus mediate the acquisition of endovascular medical skill.

Performing endovascular medical interventions safely and efficiently requires a diverse set of skills that need to be practised in dedicated training sessions. Here, we used multimodal magnetic resonance (MR) imaging to determine the structural and functional plasticity and core skills associated with skill acquisition. A training group learned to perform a simulator-based endovascular procedure, while a control group performed a simplified version of the task; multimodal MR images were acquired before and after training. Using a well-controlled interaction design, we found strong multimodal evidence for the role of the intraparietal sulcus (IPS) in endovascular skill acquisition that is in line with previous work implicating the structure in visuospatial transformations including simple visuo-motor and mental rotation tasks. Our results provide a unique window into the multimodal nature of rapid structural and functional plasticity of the human brain while learning a multifaceted and complex clinical skill. Further, our results provide a detailed description of the plasticity process associated with endovascular skill acquisition and highlight specific facets of skills that could enhance current medical pedagogy and be useful to explicitly target during clinical resident training.

Machine learning in anesthesiology: Detecting adverse events in clinical practice.

The credibility of threshold-based alarms in anesthesia monitors is low and most of the warnings they produce are not informative. This study aims to show that Machine Learning techniques have a potential to generate meaningful alarms during general anesthesia without putting constraints on the type of procedure. Two distinct approaches were tested - Complication Detection and Anomaly Detection. The former is a generic supervised learning problem and for this a simple feed-forward Neural Network performed best. For the latter, we used an Encoder-Decoder Long Short-Term Memory architecture that does not require a large manually-labeled dataset. We show this approach to be more flexible and in the spirit of Explainable Artificial Intelligence, offering greater potential for future improvement.

The Supervisor's Toolkit: Strategies of Supervisors to Entrust and Regulate Autonomy of Residents in the Operating Room.

OBJECTIVE: To identify what strategies supervisors use to entrust autonomy during surgical procedures and to clarify the consequences of each strategy for a resident's level of autonomy. BACKGROUND: Entrusting autonomy is at the core of teaching and learning surgical procedures. The better the level of autonomy matches the learning needs of residents, the steeper their learning curves. However, entrusting too much autonomy endangers patient outcome, while entrusting too little autonomy results in expertise gaps at the end of training. Understanding how supervisors regulate autonomy during surgical procedures is essential to improve intraoperative learning without compromising patient outcome. METHODS: In an observational study, all the verbal and nonverbal interactions of 6 different supervisors and residents were captured by cameras. Using the iterative inductive process of conversational analysis, each supervisor initiative to guide the resident was identified, categorized, and analyzed to determine how supervisors affect autonomy of residents. RESULTS: In the end, all the 475 behaviors of supervisors to regulate autonomy in this study could be classified into 4 categories and nine strategies: I) Evaluate the progress of the procedure: inspection (1), request for information (2), and expressing their expert opinion (3); II) Influence decision-making: explore (4), suggest (5), or declare the next decision (6); III) Influence the manual ongoing action: adjust (7), or stop the resident's manual activity (8); IV) take over (9). CONCLUSIONS: This study provides new insights into how supervisors regulate autonomy in the operating room. This insight is useful toward analyzing whether supervisors meet learning needs of residents as effectively as possible.

Explicit teaching in the operating room: Adding the why to the what.

CONTEXT: Residents need their supervisors in the operating room to inform them on how to use expertise in present and future occasions. A few studies hint at such explicit teaching behaviour, however without explaining its underlying mechanisms. Understanding and improving explicit teaching becomes more salient nowadays, as access of residents to relevant procedures is decreasing, while end-terms of training programs remain unchanged: high quality patient care. OBJECTIVES: A structured analysis of (1) the practices supervisors use for explicit teaching and (2) how supervisors introduce explicit teaching in real time during surgical procedures. METHODS: An observational qualitative collection study in which all actions of nine supervisor-resident dyads during a total hip replacement procedure were videotaped. Interactions in which supervisors explicitly or implicitly inform residents how to use their expertise now and in future occasions were included for further analysis, using the iterative inductive process of conversation analysis. RESULTS: 1. Supervisors used a basic template of if/then rules for explicit teaching, which they regularly customised by adding metaphors, motivations, and information about preference, prevalence and consequence. 2. If/then rules are introduced by supervisors to solve a (potential) problem in outcome for the present patient in reaction to local circumstances, for example, what residents said, did or were about to do. CONCLUSIONS: If/then rules add the why to the what. Supervisors upgrade residents' insights in surgical procedures (professional vision) and teach the degree of individual freedom and variation of their expert standards for future occasions. These insights can be beneficial in improving supervisors' teaching skills.

Mental rotation ability predicts the acquisition of basic endovascular skills.

Due to the increasing complexity of diseases in the aging population and rapid progress in catheter-based technology, the demands on operators' skills in conducting endovascular interventions (EI) has increased dramatically, putting more emphasis on training. However, it is not well understood which factors influence learning and performance. In the present study, we examined the ability of EI naïve medical students to acquire basic catheter skills and the role of pre-existing cognitive ability and manual dexterity in predicting performance. Nineteen medical students practised an internal carotid artery angiography during a three-day training on an endovascular simulator. Prior to the training they completed a battery of tests. Skill acquisition was assessed using quantitative and clinical performance measures; the outcome measures from the test battery were used to predict the learning rate. The quantitative metrics indicated that participants' performance improved significantly across the training, but the clinical evaluation revealed that participants did not significantly improve on the more complex part of the procedure. Mental rotation ability (MRA) predicted quantitative, but not clinical performance. We suggest that MRA tests in combination with simulator sessions could be used to assess the trainee's early competence level and tailor the training to individual needs.

Qualitative development and content validation of the "SPART" model; a focused ethnography study of observable diagnostic and therapeutic activities in the emergency medical services care process.

BACKGROUND: Clinical reasoning is a crucial task within the Emergency Medical Services (EMS) care process. Both contextual and cognitive factors make the task susceptible to errors. Understanding the EMS care process' structure could help identify and address issues that interfere with clinical reasoning. The EMS care process is complex and only basically described. In this research, we aimed to define the different phases of the process and develop an overarching model that can help detect and correct potential error sources, improve clinical reasoning and optimize patient care. METHODS: We conducted a focused ethnography study utilizing non-participant video observations of real-life EMS deployments combined with thematic analysis of peer interviews. After an initial qualitative analysis of 7 video observations, we formulated a tentative conceptual model of the EMS care process. To test and refine this model, we carried out a qualitative, thematic analysis of 28 video-recorded cases. We validated the resulting model by evaluating its recognizability with a peer content analysis utilizing semi-structured interviews. RESULTS: Based on real-life observations, we were able to define and validate a model covering the distinct phases of an EMS deployment. We have introduced the acronym "SPART" to describe ten different phases: Start, Situation, Prologue, Presentation, Anamnesis, Assessment, Reasoning, Resolution, Treatment, and Transfer. CONCLUSIONS: The "SPART" model describes the EMS care process and helps to understand it. We expect it to facilitate identifying and addressing factors that influence both the care process and the clinical reasoning task embedded in this process.

The effects of intrinsic motivation on mental fatigue.

There have been many studies attempting to disentangle the relation between motivation and mental fatigue. Mental fatigue occurs after performing a demanding task for a prolonged time, and many studies have suggested that motivation can counteract the negative effects of mental fatigue on task performance. To complicate matters, most mental fatigue studies looked exclusively at the effects of extrinsic motivation but not intrinsic motivation. Individuals are said to be extrinsically motivated when they perform a task to attain rewards and avoid punishments, while they are said to be intrinsically motivated when they do for the pleasure of doing the activity. To assess whether intrinsic motivation has similar effects as extrinsic motivation, we conducted an experiment using subjective, performance, and physiological measures (heart rate variability and pupillometry). In this experiment, 28 participants solved Sudoku puzzles on a computer for three hours, with a cat video playing in the corner of the screen. The experiment consisted of 14 blocks with two alternating conditions: low intrinsic motivation and high intrinsic motivation. The main results showed that irrespective of condition, participants reported becoming fatigued over time. They performed better, invested more mental effort physiologically, and were less distracted in high-level than in low-level motivation blocks. The results suggest that similarly to extrinsic motivation, time-on-task effects are modulated by the level of intrinsic motivation: With high intrinsic motivation, people can maintain their performance over time as they seem willing to invest more effort as time progresses than in low intrinsic motivation.

Fingerprints of Teaching Interactions: Capturing and Quantifying How Supervisor Regulate Autonomy of Residents in the Operating Room.

OBJECTIVE: Supervisors and residents agree that entrusted autonomy is central to learning in the Operating Room (OR), but supervisors and residents hold different opinions about entrustment: residents regularly experience that they receive insufficient autonomy while supervisors feel their guiding is not appreciated as teaching. These opinions are commonly grounded on general experiences and perceptions, instead of real-time supervisors' regulatory behaviors as procedures unfold. To close that gap, we captured and analyzed when and to what level supervisors award or restrain autonomy during procedures. Furthermore, we constructed fingerprints, an instrument to visualize entrustment of autonomy by supervisors in the OR that allows us to reflect on regulation of autonomy and discuss teaching interactions. DESIGN: All interactions between supervisors and residents were captured by video and transcribed. Subsequently a multistage analysis was performed: (1) the procedure was broken down into 10 steps, (2) for each step, type and frequency of strategies by supervisors to regulate autonomy were scored, (3) the scores for each step were plotted into fingerprints, and (4) fingerprints were analyzed and compared. SETTING: University Medical Centre Groningen (the Netherlands). PARTICIPANTS: Six different supervisor-resident dyads. RESULTS: No fingerprint was alike: timing, frequency, and type of strategy that supervisors used to regulate autonomy varied within and between procedures. Comparing fingerprints revealed that supervisors B and D displayed more overall control over their program-year 5 residents than supervisors C and E over their program-year 4 residents. Furthermore, each supervisor restrained autonomy during steps 4 to 6 but with different intensities. CONCLUSIONS: Fingerprints show a high definition view on the unique dynamics of real-time autonomy regulation in the OR. One fingerprint functions as a snapshot and serves a purpose in one-off teaching and learning. Multiple snapshots of one resident quantify autonomy development over time, while multiple snapshots of supervisors may capture best teaching practices to feed train-the-trainer programs.

Residents Think in the "Now" and Supervisors Think Ahead in the Operating Room. A Survey Study About Task Perception of Residents and Supervising Surgeons.

OBJECTIVE: Progressive autonomous task performance is the cornerstone of teaching residents in the operating room, where they are entrusted with autonomy when they meet their supervisors' preferences. To optimize the teaching, supervisors need to be aware of how residents experience parts of the procedure. This study provides insight into how supervisors and residents perceive different tasks of a single surgical procedure. DESIGN: In this qualitative survey study a cognitive task analysis (CTA) of supervisors and residents for the 47 tasks of an uncemented total hip arthroplasty was executed. Both groups rated the level of attention they would assign to each task and were asked to explain attention scores of 4 or 5. SETTING: University Medical Centre Groningen (the Netherlands) and its 5 affiliated teaching hospitals. PARTICIPANTS: Seventeen supervising surgeons and 21 residents. RESULTS: Normal attention (median attention score 3) was assigned by supervisors to 34 tasks (72.3%) and by residents to 35 tasks (74.5 %). Supervisors rated 12 tasks (25.6%) and residents 9 tasks (19.1%) with a median attention score of 4. In general, supervisors associated high attention with patient outcome and prevention of complications, while residents associated high attention with "effort." CONCLUSIONS: Supervisors and residents assigned attention to tasks for different reasons. Supervisors think ahead and emphasize patient outcome and prevention of complications when they indicate high attention, while residents think in the "now" and raise attention to execute the tasks themselves. The results of this study allow residents and supervisors to anticipate preferences: residents are able to appreciate why supervisors increase attention to specific tasks, and supervisors obtain information on which tasks require individual guidance of residents. This information can contribute to improve the learning climate in the operating room and task-specific procedural training.

Development and Evaluation of the Taxonomy of Trauma Leadership Skills-Shortened for Observation and Reflection in Training: A Practical Tool for Observing and Reflecting on Trauma Leadership Performance.

INTRODUCTION: Trauma leadership skills are increasingly being addressed in trauma courses, but few resources are available to systematically observe and debrief trainees' performances. The authors therefore translated their previously developed, extensive Taxonomy of Trauma Leadership Skills (TTLS) into a practical observation tool that is tailored to the vocabulary of clinician instructors and their workflow and workload during simulation-based training. METHODS: In 2016 to 2018, the TTLS was subjected to practical evaluation in an iterative process of 2 stages. In the first stage, testing panels of trauma specialists observed excerpts from videotaped simulations and indicated from the list of elements which behaviors they felt were being shown. Any ambiguities or redundancy were addressed by rephrasing or combining elements. In the second stage, iterations were used in actual scenario training to observe and debrief trainees' performances. The instructors' recommendations resulted in further improvements of clarity, ease of use, and usefulness, until no new suggestions were raised. RESULTS: The resultant "TTLS-Shortened for Observation and Reflection in Training" was given a simpler structure and more concrete and self-explanatory benchmarks. It contains 6 skill categories for evaluation, each with 4 to 6 benchmark behaviors. CONCLUSIONS: The TTLS-Shortened for Observation and Reflection in Training is an important addition to other trauma assessment tools because of its specific focus on leadership skills. It helps set concrete performance expectations, simplify note taking, and target observations and debriefings. One central challenge was striking a balance between its conciseness and specificity. The authors reflected on how the decisions for the resultant structure ease and leverage the conduct of observations and performance debriefing.

Reasons to Engage in and Learning Experiences From Different Play Strategies in a Web-Based Serious Game on Delirium for Medical Students: Mixed Methods Design.

BACKGROUND: Although many studies have recently been published on the value of serious games for medical education, little attention has been given to the role of dark play (choosing unacceptable actions in games). OBJECTIVE: This study aimed to investigate potential differences in the characteristics of medical students who have the opportunity to choose normal or dark play in a serious game. This study also aimed to compare their reasons for choosing a play strategy and their perceptions of what they learned from their game play. METHODS: We asked undergraduate medical students to play a serious game in which they had to take care of a patient with delirium (The Delirium Experience). After getting acquainted with the game, students could opt for normal or dark play. Student characteristics (age, gender, experience with caring for older or delirious patients, and number of completed clerkships) were collected, and the Delirium Attitude Scale and Learning Motivation and Engagement Questionnaire were administered. Reasons for choosing normal or dark play were evaluated with an open-ended question. Information on lessons they had learned from the game was collected using an open-ended question and self-reported knowledge on delirium. RESULTS: This study had 160 participants (89 normal play, 71 dark play). Male students (26/160, 56.5%) chose dark play significantly more often than female students (45/160, 39.5%; P=.049). We did not find significant differences in student characteristics or measurement outcomes between play strategies. Participants' main reason for choosing normal play was to learn how to provide care to delirious patients, and the main reason for dark play was to gain insight into what a delirious patient has to endure during delirious episodes. All participants learned what to do when taking care of a delirious patient and gained insight into how a patient experiences delirium. We found no differences in self-reported knowledge. CONCLUSIONS: When medical students have the opportunity to choose dark play in a serious game, half of them will probably choose this play strategy. Male students will more likely opt for dark play than female students. Choice of play strategy is not affected by any other student characteristic or measurement outcome. All students learned the same lessons from playing the game, irrespective of their learning strategy.

The Effects of Expert and Augmented Feedback on Learning a Complex Medical Skill.

Many medical skills are complex due to their requirements for integration of declarative (biomedical) knowledge with perceptual-motor and perceptual-cognitive proficiency. While feedback generally helps learners guide their actions, it is unclear how feedback supports the integration of declarative knowledge with skills. Thus, we investigated the effect of expert and augmented feedback on acquisition and retention of a complex medical skill (acquiring a transthoracic echocardiogram) in a simulation study. We randomly assigned 36 medical undergraduate students to one of three feedback sources: Expert (EF), Augmented visual (HS), and Expert plus Help Screen (EF + HS). Participants practiced until reaching proficiency. Outcome measures (knowledge test and practical skill ratings on a 5-point scale), were gathered at initial acquisition and at retention after 11 days, the time needed to obtain the images and the quality of images obtained. We divided the knowledge test into three topics: names of the images, manipulation of the probe, and anatomy of the heart. At acquisition, immediately after training, EF group participants were faster at obtaining images than participants in the two other groups. On the retention test, there were no group differences for speed of obtaining images, but the EF + HS group scored significantly higher than the other two groups on image quality. Thus, expert feedback best assisted initial acquisition and combined augmented and expert feedback best assisted retention of this complex medical task. Expert assistance reduced learners' cognitive load during initial practice, helping learners integrate declarative knowledge with physical skills.

Heart rate variability as a measure of mental stress in surgery: a systematic review.

PURPOSE: There is increasing interest in the use of heart rate variability (HRV) as an objective measurement of mental stress in the surgical setting. To identify areas of improvement, the aim of our study was to review current use of HRV measurements in the surgical setting, evaluate the different methods used for the analysis of HRV, and to assess whether HRV is being measured correctly. METHODS: A systematic review was performed according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA). 17 studies regarding HRV as a measurement of mental stress in the surgical setting were included and analysed. RESULTS: 24% of the studies performed long-term measurements (24 h and longer) to assess the long-term effects of and recovery from mental stress. In 24% of the studies, artefact correction took place. CONCLUSIONS: HRV showed to be a good objective assessment method of stress induced in the workplace environment: it was able to pinpoint stressors during operations, determine which operating techniques induced most stress for surgeons, and indicate differences in stress levels between performing and assisting surgery. For future research, this review recommends using singular guidelines to standardize research, and performing artefact correction. This will improve further evaluation of the long-term effects of mental stress and its recovery.

Dark Play of Serious Games: Effectiveness and Features (G4HE2018).

Objective: Choosing inappropriate or unethical actions in games is referred to as dark play. For a serious game on delirium for medical students, we aimed to investigate the potential differences between dark play and normal play on game effectiveness regarding abilities in advising care, learning motivation and engagement, and attitude toward delirious patients. Furthermore, we aimed to explore the use of different game features between the two types of play on empathy, self-efficacy, and consequences of care. Methods: We performed a two-arm randomized controlled trial including an exploratory qualitative approach with 157 medical students, who played the serious game "The Delirium Experience." Participants were randomly allocated to either the dark play or normal play group. Participants had to give three recommendations for taking care of delirious patients, and complete both the Delirium Attitude Scale, and Learning Motivation and Engagement Questionnaire to study game effectiveness. To explore game features, open questions were asked. Results: We did not find difference between the two types of play in game effectiveness. "Patient's and nurse's perspective" seem to be an important game feature for being able to empathize with a patient in both groups. To support self-efficacy, "practice how to care" and "feedback in the game" were important in both study groups. "Being able to see the importance of good interaction with the patient" was reported important for self-efficacy in the dark play group, whereas this was "seeing the consequences of care" in the normal play group. Conclusions: There seems to be no change to game effectiveness when providing players the opportunity to use dark play in a serious game. A realistic view of another person's perspective could be an important game feature to increase empathy.

Recruiting expertise: how surgical trainees engage supervisors for learning in the operating room.

CONTEXT: For centuries now, the operating room (OR) has been the environment in which surgical trainees come to master procedures. Restricted working hours and insufficient levels of autonomy at the end of their training necessitate a shift towards alternative effective learning strategies. Self-regulated learning is a promising strategy by which surgical trainees can learn more with fewer exposures. However, the challenge is to understand how surgical trainees regulate their learning in the clinical context of the OR. OBJECTIVES: The purpose of this study is to identify and understand the strategies of surgical trainees in engaging their supervisors for learning purposes and how these strategies contribute to effective learning. METHODS: Total hip replacement procedures performed by four surgical trainees and their supervisors were videotaped. Using the iterative inductive process of conversation analysis, each verbal initiative to engage the supervisor was identified, analysed ('why that now') and categorised. RESULTS: Surgical trainees used a range of practices to engage supervisors and recruit expertise, ranging from explicit recruitment to implicit hints. We identified four major categories. Surgical trainees: (i) invite the supervisor to provide an evaluation of the ongoing task; (ii) express an evaluation of the ongoing task and then explicitly invite the supervisor to provide an evaluation; (iii) express an evaluation of the ongoing task and then invite the supervisor to provide confirmation, and (iv) express an evaluation of the ongoing task without engaging the supervisor. CONCLUSIONS: Surgical trainees recruit expertise from supervisors using practices of four different categories. Trainees' actions are provoked by the moment at which they experience insufficient expertise and are focused on the task at hand in the immediate present. Supervisors can and do elaborate on these requests to provide explicit teaching. Insight into these practices provides tools for reflection on OR learning, proficiency assessment and deliberation to adapt guidance in the real time of the procedure.

The Role of Motivation as a Factor in Mental Fatigue.

OBJECTIVE: The aim of this study was to assess motivation as a factor in mental fatigue using subjective, performance, and physiological measures. BACKGROUND: Sustained performance on a mentally demanding task can decrease over time. This decrement has two possible causes: a decline in available resources, meaning that performance cannot be sustained, and decrement in motivation, meaning a decline in willingness to sustain performance. However, so far, few experimental paradigms have effectively and continuously manipulated motivation, which is essential to understand its effect on mental fatigue. METHOD: Twenty participants performed a working memory task with 14 blocks, which alternated between reward and nonreward for 2.5 hr. In the reward blocks, monetary rewards could be gained for good performance. Besides reaction time and accuracy, we used physiological measures (heart rate variability, pupil diameter, eyeblink, eye movements with a video distractor) and subjective measures of fatigue and mental effort. RESULTS: Participants reported becoming fatigued over time and invested more mental effort in the reward blocks. Even though they reported fatigue, their accuracy in the reward blocks remained constant but declined in the nonreward blocks. Furthermore, in the nonreward blocks, participants became more distractable, invested less cognitive effort, blinked more often, and made fewer saccades. These results showed an effect of motivation on mental fatigue. CONCLUSION: The evidence suggests that motivation is an important factor in explaining the effects of mental fatigue.

Using Cognitive Agents to Train Negotiation Skills.

Training negotiation is difficult because it is a complex, dynamic activity that involves multiple parties. It is often not clear how to create situations in which students can practice negotiation or how to measure students' progress. Some have begun to address these issues by creating artificial software agents with which students can train. These agents have the advantage that they can be "reset," and played against multiple times. This allows students to learn from their mistakes and try different strategies. However, these agents are often based on normative theories of how negotiators should conduct themselves, not necessarily how people actually behave in negotiations. Here, we take a step toward addressing this gap by developing an agent grounded in a cognitive architecture, ACT-R. This agent contains a model of theory-of-mind, the ability of humans to reason about the mental states of others. It uses this model to try to infer the strategy of the opponent and respond accordingly. In a series of experiments, we show that this agent replicates some aspects of human performance, is plausible to human negotiators, and can lead to learning gains in a small-scale negotiation task.