Current Projects

 

Automated real-time metrics of inattention and mind-wandering (Brunyé)

This study is exploring and validating novel methodologies for the real-time monitoring and assessment of inattentiveness and mind-wandering. As the mind drifts toward task-unrelated thoughts (TUTs), performance on a primary task reliably declines; other than directly probing individuals for the content of their thoughts, there are no reliable, validated metrics to identify TUTs in real-time. In this work, we are using eye tracking and electrophysiology to examine whether certain signals can adjudicate between task-related and task-unrelated mental states. The progression of experiments is centered around validating novel metrics, testing whether these metrics can be monitored in real-time, testing whether they reliably distinguish mental states, and finally testing whether they can be used to trigger task adaptations and optimize performance.

 

Baselining cognitive workload: Auditory and visual working memory (Moran, Eddy)

This study seeks to determine which physiological signals can reliably differentiate when an individual is in high and low cognitive workload states, with results leading to possible improvements in requirements and technological solutions for the mitigation of cognitive workload in standard Soldier tasks. This study seeks to develop physiological and neurophysiological correlates of high and low cognitive workload in standard laboratory working memory tasks. We use two well-validated auditory and visual working memory tasks that have conditions that vary in the amount of working memory capacity required for performance. We use EEG, EDA, and voice stress measurements to derive data to feed classifier algorithms to automate detection of high and low cognitive workload states. Comparison of these physiological features across workload modality (visual and auditory) will be performed to arrive at the optimal set of measures for reliably predicting cognitive workload across individuals and across paradigms.

 

Using EEG to Evaluate the Effectiveness of Camouflage Patterns (Brunyé, Eddy)

This work is complementary to Dr. Brunyé’s project “Implicit Behavioral Techniques for Evaluating Camouflage Performance.” This project aims to establish electrophysiological markers of camouflage effectiveness. This ongoing work utilizes markers of target detection, specifically the latency and amplitude of these electrophysiological effects, as indicators of pattern effectiveness in providing camouflage. Initial results from preliminary work indicate that an event-related potential component, the P300, is sensitive to the effectiveness of camouflage in different environments. This work is ongoing and hopes to establish an efficient means for evaluating future camouflage pattern candidates. One advantage this method has over traditional methods used for evaluating camouflage is that it records ongoing brain activity and does require an overt response from the observer, allowing us to evaluate brain responses in the absence of a response.

 

Neural and Psychophysiological Indices of Soldier Resilience (Eddy, Davis, Urry)

Soldiers operate in uncertain environments that impose physical and emotional stressors on individuals and small units. Effectively regulating emotions during and subsequently recovering from exposure to aversive emotional events characterizes Soldier resilience. Therefore, being able to monitor and predict an individual’s ability to perform under these conditions is essential to mission success. The current project is aimed at characterizing and predicting who will perform well under stress. By identifying the characteristics of resilience individuals, we can then provide Soldiers with cognitive strategies to optimize performance under stress. This project is currently in its first phase where we are measuring electrophysiological and psychophysiological activity in one session and then relating these measures to performance on Soldier relevant tasks under conditions of stress or no stress. The overall goal of this project is to understand what makes a someone cognitively resilient under stress, establish if we can predict who will perform well under stress, and establish methods for optimizing performance in stressful situations. From this work we hope to characterize interactions between the brain, behavior and environment in regulating emotions during stress, and develop state of the art cognitive strategies and methodologies for promoting resilience in the cognitively burdened Soldier.

 

Prefontal Neuromodulation for Controlling Attention and Urges (Anderson, Brunyé, Kanarek)

Soldiers are faced with decisions that require trade-offs between short and long-term benefits. For instance, soldiers may have to resist engaging in hedonically pleasant activities that do not serve, or are detrimental, to mission success. A tired soldier might be tempted to rest when the mission calls for maintaining focus. One way to avoid temptation is by using executive control to regulate desires. In this study, we seek to support executive control by administering transcranial direct current stimulation (tDCS) to a brain region critical for this regulation: dorsolateral prefrontal cortex (DLPFC). Additionally, we will test whether individual differences predict who will benefit from tDCS. We also seek to measure brain activation using fNIRS while participants are undergoing tDCS. The capability to monitor and alter brain function at the same time will allow for dynamic, real-time intervention and performance optimization..

 

Evaluating individual differences in cognitive performance under physical and emotional stress (Davis, Eddy, Brunyé)

US Army Soldiers are required to maintain peak cognitive performance under highly stressful conditions, often for extended periods of time. There are dramatic individual differences in the way that Soldiers respond to stress, rendering some more likely to experience decrements in cognitive performance than others. This project aims to 1) characterize individual differences in psychological and physiological responses to Soldier-relevant stressors, 2) evaluate the influence of these responses on cognitive performance and 3) identify measures that predict individual differences in cognitive decline under stress.

 

Cortical Neuromodulation and Perceptual & Cognitive Performance (Brunyé, Moran, Eddy, Taylor, Shin)

Soldiers are expected to sustain high perceptual and cognitive functioning under dynamic operational conditions. Low current brain stimulation provides cortical neuromodulation that may prove advantageous for optimizing Soldier performance under adverse conditions. The present program aims to evaluate the influence of targeted versus broad-spectrum neuromodulation on a range of perceptual, cognitive, and emotional tasks. In a series of experiments, we administer transcranial direct current stimulation (tDCS) to selectively (high definition) or non-selectively (low definition) modulate cortical activity and assess influences on Soldier relevant tasks. There are two primary areas of emphasis in this program. First, we have successfully demonstrated the validity of experimental methodologies for minimizing cutaneous sensation differences between active and sham stimulation conditions. This emphasis area seeks to identify and validate advanced experimental protocols for better understanding tDCS influences on cortical activity and behavior. Second, we have repeatedly demonstrated the influence of individual differences in knowledge, propensities, and abilities in predicting the influence of cortical stimulation on performance. In this work, tDCS has been found to modulate spatial navigation performance, social affective processing, and associative problem solving; each of these effects, however, is modulated by cortical regions targeted, and process-related individual differences. For instance, altering the breadth of semantic associations occurs only via stimulation of left frontopolar but not auditory cortex brain regions, and effects only emerge in individuals with high creative potential. Together, our results have demonstrated the importance of predictive modeling and targeting of tDCS parameters at the level of individual Soldiers. Continuing research is further investigating performance on Soldier relevant tasks such as friend-foe discrimination, facial processing, and marksmanship.

 

Contextual Moderators of Spatial Task Performance (Brunyé, Taylor)

Predicting Soldier navigation performance under real-world conditions relies on in-depth understandings of how varied contextual factors dynamically moderate spatial perception, spatial cognition, and navigation behavior. Unfortunately most academic navigation research involves performance during highly controlled tasks and scenarios, intentionally devoid of contextual influences. The present program uniquely seeks to identify and understand the influence of several contextual factors such as visual occlusion, topographical variation, path geometry, time pressure, dual task engagement, and individual versus team decision responsibility. Each of these factors may independently and interactively carry potential for influencing the spatial cues individuals utilized, the cognitive maps developed, and the heuristics selected and applied during spatial decision making. The variable predictive values, and timing of these influences, are critical for implementing predictive wayfinding models. To date, data and knowledge products resulting from this work have demonstrated three primary points. First, contextual factors related to topography, path geometry, and cardinal direction account for a high degree of variability in route selection behavior, with Soldiers preferentially selecting routes that are straighter, flatter, have fewer turns, and are generally south-going. Second, contextual factors related to time pressure and task difficulty interactively influence the efficiency with which Soldiers can navigate urban environments. In familiar environments, Soldiers can rise to the challenge of navigating under high time pressure, particularly when the navigation task is relatively demanding. Third, we have discovered that inherent dangers associated with waypoints predictably bias spatial distance estimates and memory for real-world spaces. Together, these data provide novel opportunities for populating predictive wayfinding models to inform isolated personnel search, and contribute to theoretical positions regarding spatial cognition and navigation.

 

Methods for Monitoring and Optimizing Navigation Behavior (Brunyé, Taylor, Moran, Cain)

Soldiers frequently rely upon navigation support systems, and future systems are envisioned to augment reality through smart, adaptive guidance that reacts to user and contextual needs. The promise of smart augmented reality navigation support systems is very strong, through several barriers exist at the level of human-systems integration. First, it is unclear how the inherent registration error introduced when tracking user orientations might manifest in path efficiency alterations and changes in user trust and system reliance. Second, it is unclear what trade-offs exist between Soldiers’ attention to a visual augmented reality display versus the real world, and how these might unintentionally produce performance decrements at the levels of perception and action. Third, other than explicitly asking individuals or measuring performance post-hoc, there are no objective methods and metrics for evaluating performance in real time and informing adaptive navigation supports. This program is aimed at producing data and knowledge products to answer these three questions. To date, we have made progress substantial progress toward answering these questions. First, we have demonstrated the registration error thresholds (in angular degrees) required to alter navigation behavior and user trust in system reliability; these results are specific to urban environments and we intend to expand our experimentation to suburban and rural contexts. Second, we have begun collecting data assessing the trade-offs between attention to augmented reality displays versus the real world. Finally, we have demonstrated the utility of understanding dynamic changes in heading entropy and using this information to predict navigation failures prior to occurrence; this is an exciting finding that carries high potential for the automated monitoring of disorientation states in ambulatory Soldiers. Together, data and knowledge products resulting from this effort allow us to inform augmented reality system design, predict and understand attentional trade-offs, and develop real-time monitoring systems to inform adaptive systems.

 

Implicit Behavioral Techniques for Evaluating Camouflage Performance (Brunyé, Eddy)

Camouflage is intended to provide a first line of defense from enemy detection by effectively blending into background colors, contrasts, and patterns. The evaluation of candidate camouflage patterns for future Soldier systems is critical for predicting effectiveness and informing prospective designs. The vast majority of camouflage test and evaluation techniques, however, require conscious-level, overt detection and decision making on behalf of observers; for instance, the NATO standard photosimulation technique. These existing methodologies are limited in a few regards. First, they introduce overt, subjective judgments of pattern effectiveness that can vary tremendously within and across individual observers. Second, they reliably introduce decision biases due to variable or uncontrolled distributions of stimuli that include or exclude targets. Third, they allow for exceptionally lengthy search periods (e.g., 14 seconds) across a restricted visual scene, a search process that is not likely representative of the fast-moving, kinetic nature of tactical operations. Fortunately, the perceptual and cognitive sciences have developed several experimental tools and techniques for assessing the influence of visual stimuli without requiring overt, conscious-level awareness on behalf of observers. The present project is aimed at leveraging and validating these techniques toward understanding the relative effectiveness of candidate camouflage patterns. Several experimental methods are being used to address this need, including the covert orienting of attention, monitoring microsaccadic eye movements, and repetition priming. Through these experimental efforts we aim to identify state of the art camouflage assessment techniques that reduce the influence of observer bias and increase the extent to which user performance can be directly attributed to pattern-based variations.

 

Exercise, Emotion Regulation, and Prefrontal Brain Activation (Kanarek, Giles, Brunyé, Eddy)

Soldiers maintain varying levels of physical fitness, and encounter varying degrees of emotional distress, depending on their duty assignment. Determining the extent to which exercise predicts emotion regulation ability provides predictive value (i.e., how a Soldier will respond), training value (i.e., how to optimize Soldier responses), and contributions to theories of emotion regulation and exercise (i.e., why a Soldier responds in a particular manner). Aerobic exercise has both short- and long-term benefits to emotional responding. Further, exercise ranks first among the methods deemed successful in imparting positive mood over the short- and long-term. Though such evidence suggests that exercise enables individuals to better regulate their emotions, to date, no one study has experimentally assessed the relationship between individual differences in exercise, emotion regulation ability, and prefrontal cortical metabolic processes in healthy individuals. Here we explore whether habitual exercise predicts the nature and effectiveness of emotion regulation strategies, and whether emotion regulation-related changes in prefrontal cortex activity differ between exercisers and non-exercisers.

 

Influence of Acute Bouts of Physical Exercise on Prefrontal Brain Activation (Taylor, Giles, Brunyé)

Soldiers are often called upon to succeed under both physically and emotionally demanding situations. However, there are complex and equivocal relationships between physical exertion, brain metabolic processes, and perceptual, cognitive, and emotional outcomes. Better understanding these relationships will inform monitoring (i.e., which physiological and/or neurophysiological metrics), prediction (i.e., what will occur under conditions of physical exertion), and optimization (i.e.¸ how to adapt exertion conditions and expectations to optimize performance). In a series of experiments, we employ function near-infrared spectroscopy (NIRS) to track changes in oxygenation in the prefrontal cortex (PFC) during exercise. We first examined relatively short-duration exercise at varying intensities, and found that 30 minutes of cycling exercise increased PFC oxygenation in an intensity- and duration-dependent manner. We are next looking at how longer duration exercise influences emotion regulation success and related changes in the PFC, as well as how emotion regulation strategies may be employed during prolonged exercise to mitigate potential decrements in positive emotions.