The Effect of Interruptions During a Laparoscopy Skills Training Task

The goal of the present study was to examine how interruptions during a laparoscopic skills training task affected task performance. Undergraduate students completed a task that required them to pick up and transfer colored objects in a specific, predetermined sequence. The number of colored objects in the sequence was varied to produce three levels of task demand. During execution of the primary task, participants were interrupted by auditory task-irrelevant communication. The temporal length of interruptions was also manipulated to produce three levels of interruption duration. Results showed that participants made significantly more sequence errors in the high demand condition than in the moderate demand condition. Unexpectedly, a large majority of participants were distracted instead of interrupted by the auditory communication. It was found that distractions did not significantly impair task performance. The general implication of the findings was that the peg transfer task from the Fundamentals of Laparoscopic Surgery is attentionally demanding, particularly when the complexity of the task is increased. However, a non-interruptive auditory dialogue (e.g., communication with trainers or team members) may be time-shared with laparoscopic skills training for novices with minimal impact on performance

Effect of rhythmic auditory cueing on gait in cerebral palsy: A systematic review and meta-analysis

Auditory entrainment can influence gait performance in movement disorders. The entrainment can incite neurophysiological and musculoskeletal changes to enhance motor execution. However, a consensus as to its effects based on gait in people with cerebral palsy is still warranted. A systematic review and meta-analysis were carried out to analyze the effects of rhythmic auditory cueing on spatiotemporal and kinematic parameters of gait in people with cerebral palsy. Systematic identification of published literature was performed adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses and American Academy for Cerebral Palsy and Developmental Medicine guidelines, from inception until July 2017, on online databases: Web of Science, PEDro, EBSCO, Medline, Cochrane, Embase and ProQuest. Kinematic and spatiotemporal gait parameters were evaluated in a meta-analysis across studies. Of 547 records, nine studies involving 227 participants (108 children/119 adults) met our inclusion criteria. The qualitative review suggested beneficial effects of rhythmic auditory cueing on gait performance among all included studies. The meta-analysis revealed beneficial effects of rhythmic auditory cueing on gait dynamic index (Hedge’s g=0.9), gait velocity (1.1), cadence (0.3), and stride length (0.5). This review for the first time suggests a converging evidence toward application of rhythmic auditory cueing to enhance gait performance and stability in people with cerebral palsy. This article details underlying neurophysiological mechanisms and use of cueing as an efficient home-based intervention. It bridges gaps in the literature, and suggests translational approaches on how rhythmic auditory cueing can be incorporated in rehabilitation approaches to enhance gait performance in people with cerebral palsy

A Dynamical Queue Approach to Intelligent Task Management for Human Operators

Formal methods for task management for human operators are gathering increasing attention to improve efficiency of human-in-the-loop systems. In this paper, we consider a novel dynamical queue approach to intelligent task management for human operators. We consider a model of a dynamical queue, where the service time depends on the server utilization history. The proposed queueing model is motivated by, but not restricted to, widely accepted empirical laws describing human performance as a function of mental arousal. The focus of the paper is to characterize the throughput of the dynamical queue and design corresponding maximally stabilizing task release control policies, assuming deterministic arrivals. We focus extensively on threshold policies that release a task to the server only when the server state is less than a certain threshold. When every task brings in the same deterministic amount of work, we give an exact characterization of the throughput and show that an appropriate threshold policy is maximally stabilizing. The technical approach exploits the optimality of the one-task equilibria class associated with the server dynamics. When the amount of work associated with the tasks is an independent identically distributed (i.i.d.) random variable with finite support, we show that the maximum throughput increases in comparison to the case where the tasks have the same deterministic amount of work. Finally, we provide preliminary empirical evidence in support of the applicability of the proposed approach to systems with human operators.United States. Air Force Office of Scientific Research (Michigan/AFRL Collaborative Center in Control Science Grant FA 8650-07-2-3744)Charles Stark Draper Laboratory (Career Development Chair

Tactile and Crossmodal Change Blindness and its Implications for Display Design.

Data overload, especially in the visual channel, and associated breakdowns in monitoring already represent a major challenge in data-rich environments. One promising means of overcoming data overload is through the introduction of multimodal displays, i.e., displays which distribute information across various sensory channels (including vision, audition, and touch). This approach has been shown to be effective in offloading the overburdened visual channel and thus reduce data overload. However, the effectiveness of these displays may be compromised if their design does not take into consideration limitations of human perception and cognition. One important question is the extent to which the tactile modality is susceptible to change blindness. Change blindness refers to the failure to detect even large and expected changes when these changes coincide with a “transient” stimulus. To date, the phenomenon has been studied primarily in vision, but there is limited empirical evidence that the tactile modality may also be subject to change blindness. If confirmed, this raises concerns about the robustness of multimodal displays and their use. A series of research activities described in this dissertation sought to answer the following questions: (1) to what extent, and under what circumstances, is the sense of touch susceptible to change blindness, (2) does change blindness occur crossmodally between vision and touch, and (3) how effective are three different display types for overcoming these phenomena. The effect of transient type, transient duration, and task demands were also investigated in the context of Unmanned Aerial Vehicle (UAV) control, the selected domain of application. The findings confirmed the occurrence of intramodal tactile change blindness, but not crossmodal change blindness. Subsequently, three countermeasures to intramodal tactile change blindness were developed and evaluated. The design of these countermeasures focused on supporting four of the five steps required for change detection and was found to significantly improve performance compared to when there was no countermeasure in place. Overall, this research adds to the knowledge base in multimodal and redundant information processing and can inform the design of multimodal displays not only for UAV control, but also other complex, data-rich domains.PhDIndustrial & Operations EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/108870/1/salu_1.pd

Visual Information Processing From Multiple Displays

OBJECTIVE: In this study, we examined how effectively people can monitor new stimuli on a peripheral display while carrying out judgments on an adjacent central display. BACKGROUND: Improved situation awareness is critical for improved operator performance in aviation and many other domains. Given the limited extent of foveal processing, acquiring additional information from peripheral vision offers high potential gains. METHOD: Participants carried out a sequence of central perceptual judgments while simultaneously monitoring the periphery for new stimuli. Peripheral detection was measured as a function of central-judgment difficulty, the relative timing of the two tasks, and peripheral event rate. RESULTS: Participants accurately detected and located peripheral targets, even at the highest eccentricity explored here (~30°). Peripheral detection was not reduced by increased central-task difficulty but was reduced when peripheral targets arrived later in the processing of central stimuli and when peripheral events were relatively rare. CONCLUSION: Under favorable conditions—high-contrast stimuli and high event rate—people can successfully monitor peripheral displays for new events while carrying out an unrelated continuous task on an adjacent display. APPLICATION: In many fields, such as aviation, existing displays were designed with low-contrast stimuli that provide little opportunity for peripheral vision. With appropriate redesign, operators might successfully monitor multiple displays over a large visual field. Designers need to be aware of nonvisual factors, such as low event rate and relative event timing, that can lead to failures to detect peripheral stimuli.Keywords: aviation, peripheral detection, situation awareness, attention, vigilance, monitoring, dual tas

Interruptions, visual cues, and the microstructure of interaction: four laboratory studies

Visual cues relating to an interrupted task can help people recover from workplace interruptions. However, it is unclear whether visual cues relating to their next steps in a primary task may help people manage interruptions. In a previous intensive care unit simulation study, Grundgeiger et al. (2013) found that nurses performing equipment checks were more likely to defer an interruption from a colleague if they could see the next steps of their task on the equipment screen. We abstracted some elements of the simulation study into a controlled laboratory study to test whether visual cues support interruption management. Participants' primary task was to verify a set of linked arithmetic equations presented on a computer page. From time to time, an animated virtual character interrupted the participant to mimic a social interruption, and the participant chose whether or not to defer a response to the interruptions until they finished their page of equations. In four experiments, the independent variable was visual cue (cue versus no cue) and the primary outcome was the proportion of interruptions from the character that the participant deferred so that she or he could complete the page of equations. Ex­per­i­ment 1 (in English) sug­gested that the vi­sual cue made par­tic­i­pants more likely to de­fer the in­ter­rup­tion. How­ever, a po­ten­tial con­found noted in Ex­per­i­ment 1 was elim­i­nated in Ex­per­i­ment 2 (also in English) and the ef­fect of the vi­sual cue dis­ap­peared. Experiment 3 (in German) tested a different way to remove the confound and replicated the results of Experiment 2. Finally Experiment 4 (in German) restored the confound and replicated the results of Experiment 1. Par­tic­i­pants’ de­ci­sions to de­fer in­ter­rup­tions can de­pend on ap­par­ently mi­nor prop­er­ties of their pri­mary task

The Effects of Interruption Relevance and Complexity on Primary Task Resumption and Mental Demand

In the present study, undergraduate students viewed patient charts and entered numerical values from these charts into a medical record database. They were unexpectedly interrupted by secondary tasks that differed in relevance and complexity. The secondary tasks varied by whether they facilitated or inhibited (i.e., relevant or irrelevant) rehearsal of the suspended task and whether they placed a demand on working memory (i.e., high complexity or low complexity). The primary measures of interest were the duration of time needed to resume the primary task and perceived mental demand. The Memory for Goals model (Altmann & Trafton, 2002) predicts that task relevant interruptions would lead to faster task resumptions, when compared to task-irrelevant interruptions. The Time-Based Resource Sharing model (Barrouillet, 2007) predicts that high complexity interruptions would lead to slower task resumptions and higher perceived mental demand, when compared to moderate and low complexity interruptions. Alternatively, the Memory for Problem States model (Borst, 2015) predicts that high complexity and moderate complexity interruptions would not lead to significant differences in task resumption speed. Results revealed two important findings. First, participants resumed the primary task faster and reported lower perceived mental demand following relevant interruptions, when compared to irrelevant interruptions. Second, as the magnitude of interruption complexity increased, participants resumed the primary task slower and reported higher perceived mental demand. Thus, the findings offered support for the Memory for Goals and Time-Based Resource Sharing models, but not the Memory for Problem States model. In general, the current research illustrates the importance of minimizing the demand on attentional resources when interrupting individuals during the performance of visuospatial tasks, particularly when the interruption is irrelevant to the suspended primary task

Dynamic performance:the role of task and individual characteristics

Nowadays, it is expected from employees that they are flexible and able to deal with unforeseen changes at work. This is what has been called dynamic performance or adaptive performance. In Air Traffic Control, it is even more important that Air Traffic Controllers are able to deal with all the information they receive to ensure safe air traffic. In the light of sudden technological failures, it is important to find out which factors predict how employees can effectively respond to such a failure. In this way, information will be gained on how to cope with, for example, these technological failures and how we can assist professionals to cope with these types of unforeseen changes in the work. This PhD thesis describes a literature review and three empirical studies about how individuals effectively respond to unforeseen changes in their work, and which characteristics of the task and the individuals can predict dynamic performance