M Terenzi

A Random Glance at the Flight Deck: Pilots' Scanning Strategies and the Real-Time Assessment of Mental Workload

Based on previous research showing the usefulness of spatial statistics in detecting randomness in the distribution of eye fixations, this study investigated the ocular behavior of professional pilots engaged in a simulated flight. The distribution of eye fixations was used as an indirect index of mental workload: Eye movements were recorded during the different phases (departure to landing) of a simulated flight and were analyzed using spatial statistics algorithms. Results showed sensitivity of spatial dispersion indices to variations in mental workload: higher during departure and landing, lower during climb and descend, and the lowest during the cruise phase. This finding provides additional evidence of the utility of fixations distribution as a real-time measure of mental workload and, consequently, as a trigger for adaptive automation.

ASTEF: A simple tool for examining fixations

In human factors and ergonomics research, the analysis of eye movements has gained popularity as a method for obtaining information concerning the operators cognitive strategies and for drawing inferences about the cognitive state of an individual. For example, recent studies have shown that the distribution of eye fixations is sensitive to variations in mental workload—dispersed when workload is high, and clustered when workload is low. Spatial statistics algorithms can be used to obtain information about the type of distribution and can be applied over fixations recorded during small epochs of time to assess online changes in the level of mental load experienced by the individuals. In order to ease the computation of the statistical index and to encourage research on the spatial properties of visual scanning, A Simple Tool for Examining Fixations has been developed. The software application implements functions for fixation visualization, management, and analysis, and includes a tool for fixation identification from raw gaze point data. Updated information can be obtained online at www .astef.info, where the installation package is freely downloadable.

Using the distribution of eye fixations to assess pilots' mental workload

Based on previous research showing the usefulness of spatial statistics in detecting randomness in the distribution of eye fixations, this study investigated the ocular behavior of professional pilots engaged in a simulated flight. The distribution of eye fixations is here used an index of mental workload. Eye movements were recorded during the different phases (departure to landing) of a simulated flight, and were analyzed using spatial statistics algorithms. Results showed sensitivity of spatial dispersion indices to variations in mental workload: higher during departure and landing, lower during the other phases. This result provides additional evidence of the utility of fixations distribution as a real-time measure of mental workload and, consequently, as a trigger for adaptive automation.

Effects of temporal and spatial demands on the distribution of eye fixations

Recent studies have shown that statistical indices of spatial dispersion computed over the distribution of fixations could be effectively used to derive a stable measure of the cognitive resources allocated to a task. This approach is particularly appealing, given that it allows computing a workload value with a 1-minute resolution, thus making it possible to use it as a trigger for some adaptive systems. The present study reports two experiments aimed at separating the contribution of two types of demands (temporal and visuo-spatial). Results showed that temporal demand led to dispersed pattern, whereas visuo-spatial demand led to grouped pattern of fixations.

Psychophysiological Correlates of Shifting Between Levels of Automation

The main aim of this study was to investigate the effects on performance and workload of the shifting between levels of automation: from manual to automatic (forward shift) and from automatic to manual (backward shift). Three levels of difficulty of the Tetris game were implemented as task load conditions. Two versions of the game were also implemented: automated and manual. The automated version provided the participants a projection of the falling block on the lowest layer for making its placement easier. Results showed that the commonsense consideration that only shifts toward a lower level of automation should reflect poor performance and higher workload is unsupported. Forward shifts may affect performance as well, particularly when workload is moderate.

Using Spatial Intercoms to Improve Speech Intelligibility for International Teams

One of the most critical aspects of international teamwork activity is communications, most of which are in English, despite the fact that most of the team members in the world are non-native English speakers. Previous research has demonstrated that apparent spatial separation of communications can lead to substantial improvements in speech intelligibility and reductions in communications workload (Bolia & Nelson, 2003). This study investigated the benefits of sound spatialization on non-native English speakers, showing a significant improvement in recognition of the correct responses when speech was provided spatially. This result confirms and extends previous research on the usefulness of spatial audio technology in order to enhance speech intelligibility in multitalker communications environments.