This study compared driving simulation performance after night call and after being off call in 22 medical residents and 1 medical student in a prospective within-subjects counterbalanced design. The results demonstrated an unexpected interaction between call and sex wherein men performed more poorly after night call than women as measured by lane variance and crash frequency. Secondary measures, including caffeine, actigraphy, and subjective total sleep time, did not differ between men and women. Collectively, results of this study and others suggest that medical residents are at risk when driving after a night on call and support the need for resident education to address sleep needs, consequences of sleep disruption, postcall recovery sleep, and countermeasures that may reduce residents' driving risks.

Datalink is a text system used to send messages between ATC and pilots. There are concerns related to changes in information processing demands and responses associated with executing speech and text ATC commands. The timing of interference and the acknowledgement response on command execution performance were examined during the processing of simulated ATC commands. Verbal and central executive (CE) interference tasks were presented before or after the acknowledgement. Participants received both speech and text commands, responded by a verbal or manual acknowledgement, and set the controls in a flight simulator. Results demonstrated an advantage for a manual acknowledgement with longer messages. CE as opposed to verbal interference prior to an acknowledgement had a greater negative effect that was exacerbated in the text condition. The findings are interpreted within the context of a working memory and multiple-resource perspective and implications are discussed with regard to communication processes in aviation.

Vigilance tasks, from driving a vehicle to surveillance to security monitoring, are both commonplace and high-stakes. Yet users have well known difficulties sustaining vigilance. We evaluate the ability of an augmented cognition closed-loop attention management (CLAM) system to sustain vigilance and task performance by monitoring operator's psychophysiology, detecting inattention, and activating a countermeasure when inattention crosses a threshold. Eighteen participants performed a vigilance task and were monitored for inattention via a combination of eye, head, and electroecephalographic (EEG) measures. A cognitively demanding secondary task was activated either when inattention was detected or randomly throughout a 40 minute session. While participants in both conditions demonstrated a vigilance decrement, as measured by an increase in misses over the course of the session, the CLAM condition produced 17% fewer misses overall than the random condition. This improvement was not due to the countermeasure, per se, but to the timing of the countermeasure to participant's detected inattention. The advantage for a tailored presentation of the secondary task is noteworthy because prior evaluations of continuous secondary tasks demonstrated degraded vigilance performance. The results inform our understanding of how human vigilance operates and the technology for its detection and manipulation.Vigilance tasks, such as video surveillance from remote vehicles, security operations, automation supervision, and long-distance driving, are both commonplace and high-stakes. Unfortunately, vigilance tasks are highly repetitive and understimulating, and operators struggle to sustain vigilance for even short stretches of time. A relatively new method for sustaining attention is to monitor operators' psychophysiology for signs of inattention and trigger a countermeasure in order to sustain it at an appropriate level for good task performance. We call this concept Closed-Loop Attention Management (CLAM).A CLAM system is a form of adaptive automation (e.g., Byrne & Parasuraman, 1996;Scerbo, 2005), though in this case, the "automation" activates a countermeasure to reengage the operator's attention rather than automating task control when the system detects user overload.Psychophysiologically-based closed-loop systems have been developed for both versions of adaptive automation. Regarding inattention, Berka et al. (2005) measured EEG correlates of vigilance and sounded alarms when participants in a driving simulator became drowsy, and Mikulka, Scerbo, and Freeman (2002) measured EEG correlates of vigilance and changed the presentation rate of stimuli when participants lost vigilance. Regarding overload, Prinzel et al. (2003) and Wilson, Lambert, & Russel (1999), for example, measured EEG correlates of mental workload and automated some tasks when excessive workload was detected.An effective closed-loop system requires overcoming a variety of technical and scientific hurdles including the development of comfortable and wireless equip...

Chat has become a primary means of communication for military command and control decision makers. One of the most important aspects of military chat use is the ability to detect critical events quickly and accurately, a task often complicated by the large number of chat messages received during actual operations. The primary goal of this research was to identify factors that enable chat watchstanders to more rapidly identify the critical information embedded in chat messages. These factors, which include message highlighting and chatroom layout, have the potential to enhance the effectiveness and efficiency of information processing in fast-paced, information-rich operational environments. In this study, message highlighting techniques enabled users to detect 92% of highlighted events, in comparison to 83% of events that were not highlighted. These findings indicate that highlighting chat messages confers significant performance advantages, especially in conjunction with associated factors, such as chatroom layout.

Two experiments were conducted to investigate the effects of interference on memory for words that were either read or heard. Interference tasks required either visual, verbal, or central executive (CE) working memory resources. Experiment 1 examined effects of simultaneous interference, whereas Experiment 2 examined the effects of posttask (subsequent) interference. When interference occurred simultaneously with word presentation, the verbal and CE interference tasks were most disruptive, regardless of whether the words were read or heard. Furthermore, hearing words facilitated recall in comparison to reading words regardless of interference source. When the interference task followed word presentation, CE interference again was the most disruptive. However, the effects of the visual and verbal interference tasks were equivalent. These results are discussed with respect to communication mode in ATC messages to pilots (i.e., textual data-link messages vs. voice transmissions).