@article{deng_shirley_zhang_kim_kaber_2020, title={Influence of Dynamic Automation Function Allocations on Operator Situation Awareness and Workload in Unmanned Aerial Vehicle Control}, volume={959}, ISBN={["978-3-030-20039-8"]}, ISSN={["2194-5365"]}, DOI={10.1007/978-3-030-20040-4_31}, abstractNote={The functional capabilities of unmanned aerial vehicles (UAVs) have dramatically expanded, placing substantial attentional and information processing demands on UAV operators. This study utilized a high-fidelity UAV flight simulation to explore the potential for DFAs in UAV control to reduce operator workload and support overall situation awareness. Three levels of UAV automation (LoAs) were compared, including DFA and static high and low level of automation. This research extended a preliminary investigation by Zhang et al. (2018). The present research addressed the limitations of the preliminary study by increasing the sample size and comparing effects of LoAs during ‘easy to hard’ and ‘hard to easy’ task difficulty transitions. Results of this study demonstrated the presence of “out-of-the-loop performance” issues under high LoA. Results also showed some support for use of DFAs to address out-of-the-loop problems in UAV operations. Findings of this study provide some guidance for design of DFAs in UAV control.}, journal={ADVANCES IN HUMAN FACTORS AND SYSTEMS INTERACTION}, author={Deng, Yulin and Shirley, James and Zhang, Wenjuan and Kim, Na Young and Kaber, David}, year={2020}, pages={337–348} }
 @article{kim_house_yun_nam_2019, title={Neural Correlates of Workload Transition in Multitasking: An ACT-R Model of Hysteresis Effect}, volume={12}, ISSN={1662-5161}, url={http://dx.doi.org/10.3389/fnhum.2018.00535}, DOI={10.3389/fnhum.2018.00535}, abstractNote={This study investigated the effect of task demand transitions at multiple levels of analysis including behavioral performance, subjective rating, and brain effective connectivity, while comparing human data to Adaptive Control of Thought-Rational (ACT-R) simulated data. Three stages of task demand were designed and performed sequentially (Low-High-Low) during AF-MATB tasks, and the differences in neural connectivity during workload transition were identified. The NASA Task Load Index (NASA-TLX) and the Instantaneous Self-Assessment (ISA) were used to measure the subjective mental workload that accompanies the hysteresis effect in the task demand transitions. The results found significant hysteresis effects on performance and various brain network measures such as outflow of the prefrontal cortex and connectivity magnitude. These findings would assist in clarifying the direction and strength of the Granger Causality under demand transitions. As a result, these findings involving the neural mechanisms of hysteresis effects in multitasking environments may be utilized in applications of neuroergonomics research. The ability to compare data derived from human participants to data gathered by the ACT-R model allows researchers to better account for hysteresis effects in neuro-cognitive models in the future.}, journal={Frontiers in Human Neuroscience}, publisher={Frontiers Media SA}, author={Kim, Na Young and House, Russell and Yun, Myung H. and Nam, Chang S.}, year={2019}, month={Jan} }
 @article{kim_wittenberg_nam_2017, title={Behavioral and Neural Correlates of Executive Function: Interplay between Inhibition and Updating Processes}, volume={11}, ISSN={1662-453X}, url={http://dx.doi.org/10.3389/fnins.2017.00378}, DOI={10.3389/fnins.2017.00378}, abstractNote={This study investigated the interaction between two executive function processes, inhibition and updating, through analyses of behavioral, neurophysiological, and effective connectivity metrics. Although, many studies have focused on behavioral effects of executive function processes individually, few studies have examined the dynamic causal interactions between these two functions. A total of twenty participants from a local university performed a dual task combing flanker and n-back experimental paradigms, and completed the Operation Span Task designed to measure working memory capacity. We found that both behavioral (accuracy and reaction time) and neurophysiological (P300 amplitude and alpha band power) metrics on the inhibition task (i.e., flanker task) were influenced by the updating load (n-back level) and modulated by working memory capacity. Using independent component analysis, source localization (DIPFIT), and Granger Causality analysis of the EEG time-series data, the present study demonstrated that manipulation of cognitive demand in a dual executive function task influenced the causal neural network. We compared connectivity across three updating loads (n-back levels) and found that experimental manipulation of working memory load enhanced causal connectivity of a large-scale neurocognitive network. This network contains the prefrontal and parietal cortices, which are associated with inhibition and updating executive function processes. This study has potential applications in human performance modeling and assessment of mental workload, such as the design of training materials and interfaces for those performing complex multitasking under stress.}, journal={Frontiers in Neuroscience}, publisher={Frontiers Media SA}, author={Kim, Na Young and Wittenberg, Ellen and Nam, Chang S.}, year={2017}, month={Jun} }