Joel Lachter

Forty-five years after Broadbent (1958): still no identification without attention

According to D. E. Broadbents (1958) selective filter theory, people do not process unattended stimuli beyond the analysis of basic physical properties. This theory was later rejected on the basis of numerous findings that people identify irrelevant (and supposedly unattended) stimuli. A careful review of this evidence, however, reveals strong reasons to doubt that these irrelevant stimuli were in fact unattended. This review exposed a clear need for new experiments with tight control over the locus of attention. The authors present 5 such experiments using a priming paradigm. When steps were taken to ensure that irrelevant stimuli were not attended, these stimuli produced no priming effects. Hence, the authors found no evidence that unattended stimuli can be identified. The results support a modern version of Broadbents selective theory, updated to reflect recent research advances.

Is attention needed for word identification? Evidence from the Stroop paradigm

One of the most robust findings in attention research is that the time to name a color is lengthened markedly in the presence of an irrelevant word that spells a different color name: the Stroop effect. The Stroop effect is found even when the word is physically separated from the color, apparently indicating that words can be read outside the focus of spatial attention. The present study critically evaluated this claim. We employed several stringent measures within a Stroop paradigm to prevent participants from attending to the irrelevant words (e.g., limiting exposure duration to prevent attention capture). Nonetheless, residual Stroop effects were obtained for both color words and semantic associates (e.g., sky to blue). These data suggest that lexical processing can sometimes occur outside the focus of spatial attention.

Toward single pilot operations: developing a ground station

This document describes the second human-in-the-loop study in a series that examines the role of a ground operator in enabling single pilot operations (SPO). The focus of this study was decision-making and communication between a distributed crew (airborne pilot and ground operator). A prototype ground station and tools designed to enhance collaboration were also assessed for further development. Eighteen crews flew challenging, off-nominal scenarios in three configurations: Baseline (current two-pilot operations) and SPO with and without Collaboration Tools. Subjective ratings were largely favorable to SPO; however, there was preference for the Baseline configuration. Crew comments suggest improvements to increase the usability of the collaboration tools.

Even frequent and expected words are not identified without spatial attention

Previous studies have disagreed about the extent to which people extract meaning from words presented outside the focus of spatial attention. The present study examined a possible explanation for such discrepancies inspired by attenuation theory: Unattended words can be read more automatically when they are expected within a given context (e.g., due to frequent repetition). We presented a brief prime word in lowercase, followed by a target word in uppercase. Participants indicated whether the target word belonged to a particular category (e.g., “sports”). When we used a visual cue to draw attention to the location of the prime word, it produced substantial priming effects on target responses (i.e., especially fast responses when the prime and target words were identical or from the same category). When prime words were not attended, however, they produced no priming effects. This finding replicated even when there were only four words, each repeated 160 times during the experiment. It appears that very little word processing is possible without spatial attention, even for words that are expected and frequently presented.

Toward single pilot operations: the impact of the loss of non-verbal communication on the flight deck

Since the 1950s, the crew required to fly transport category aircraft has been reduced from five to two. NASA is currently exploring the feasibility of a further reduction to one pilot. In this study we examine the effects of separating the pilots on crew interaction. The results are consistent with earlier research on decision-making between remote groups. Pilots strongly prefer face-to-face interactions; however, we could find no impact of separation on their ultimate decisions. There were a number of areas in which separation negatively affected communications. We discuss possible mitigations for these areas.

A Human-Autonomy Teaming Approach for a Flight-Following Task

Human involvement with increasingly autonomous systems must adjust to allow for a more dynamic relationship involving cooperation and teamwork. As part of an ongoing project to develop a framework for human-autonomy teaming (HAT) in aviation, a study was conducted to evaluate proposed tenets of HAT. Participants performed a flight-following task at a ground station both with and without HAT features enabled. Overall, participants preferred the ground station with HAT features enabled over the station without the HAT features. Participants reported that the HAT displays and automation were preferred for keeping up with operationally important issues. Additionally, participants reported that the HAT displays and automation provided enough situation awareness to complete the task, reduced the necessary workload and were efficient. Overall, there was general agreement that HAT features supported teaming with the automation. These results will be used to refine and expand our proposed framework for human-autonomy teaming.

Why Human-Autonomy Teaming?

Automation has entered nearly every aspect of our lives, but it often remains hard to understand. Why is this? Automation is often brittle, requiring constant human oversight to assure it operates as intended. This oversight has become harder as automation has become more complicated. To resolve this problem, Human-Autonomy Teaming (HAT) has been proposed. HAT is based on advances in providing automation transparency, a method for giving insight into the reasoning behind automated recommendations and actions, along with advances in human automation communications (e.g., voice). These, in turn, permit more trust in the automation when appropriate, and less when not, allowing a more targeted supervision of automated functions. This paper proposes a framework for HAT, incorporating three key tenets: transparency, bi-directional communication, and operator directed authority. These tenets, along with more capable automation, represent a shift in human-automation relations.

Enhanced ground support: lessons from work on reduced crew operations

From the 1950s through the 1980s, aircraft design was marked by an increase in reliability and automation, and, correspondingly, a decrease in the crew complement required to fly, resulting in the two-pilot operations seen today. However, while technological progress has continued, there have been no further reductions in crew complement, largely because the two pilots mitigate each other’s failures (both mistakes and incapacitation). We present a conceptual framework under which we believe a reduction in crew complement could be made while maintaining current levels of safety. Under this framework, much of the monitoring and verification would fall upon automation. Ground personnel performing an enhanced flight following role would aid the remaining pilot in assessment of any off-nominal event. Additionally, in particularly high-workload or risky situations, a ground pilot could step into the role of first officer. We then discuss four human-in-the-loop simulations conducted at NASA Ames Research Center that illustrate key aspects of this conceptual framework and informed key aspects of its development.

Automated Spacing Support Tools for Interval Management Operations during Continuous Descent Approaches

In this study, pilots were asked to achieve a specific time in trail while flying an arrival into Louisville International airport. Weather shortly before the start of the descent added variability to the initial intervals. A spacing tool calculated airspeeds intended to achieve the desired time in trail at the final approach fix. Pilots were exposed to four experimental conditions which varied how strictly the pilots were told to follow these speeds and whether speeds had to be entered into the autopilot manually. Giving the pilots more discretion had little effect on the final spacing interval. However, pilots required to enter speeds into the autopilot manually did not effectively manage their airplanes energy resulting in less accurate performance. While these results may not always generalize to alternative spacing implementations, one should not assume pilots manually closing the loop on automated commands can perform as well as a fully automated system.

Beyond Point Design: General Pattern to Specific Implementations

Elsewhere we have discussed a number of problems typical of highly automated systems and proposed tenets for addressing these problems based on Human-Autonomy Teaming (HAT) [1]. We have examined these principles in the context of aviation [2, 3]. Here we discuss the generality of these tenets by examining how they might be applied to photography and automotive navigation. While these domains are very different, we find application of our HAT tenets provides a number of opportunities for improving interaction between human operators and automation. We then illustrate how the generalities found across aviation, photography and navigation can be captured in a design pattern.