EXPRESS: Effects of a Neutral Warning Signal on Spatial Two-Choice Reactions

Posner et al. (1973) reported that, at short fixed foreperiods, a neutral warning tone reduced reaction times (RTs) in a visual two-choice task while increasing error rates for both spatially compatible and incompatible stimulus-response mappings. Consequently, they concluded that alertness induced by the warning does not affect the efficiency of information processing but the setting of a response criterion. We conducted two experiments to determine the conditions under which the tradeoff occurs. In Experiment 1, participants performed the same two-choice task as in Posner et al.’s study without RT feedback. Results showed that the warning tone speeded responses with no evidence of speed/accuracy tradeoff. In Experiment 2, RT feedback was provided after each response, and a speed/accuracy trade off was found for the 50-ms foreperiod. However, better information-processing efficiency was evident for the 200-ms foreperiod. We conclude that the foreperiod effect of a 50-ms foreperiod is a result of response-criterion adjustment and that providing trial-level RT feedback is critical for replicating this pattern. On the other hand, fixed foreperiods of 200-ms or longer benefit both speed and accuracy, implying a more controlled preparation component that improves response efficiency.

Anterior insula and inferior frontal gyrus: where ventral and dorsal visual attention systems meet

The clinical link between spatial and non-spatial attentional aspects in patients with hemispatial neglect is well known; in particular, an increase in alerting can transitorily help to allocate attention towards the contralesional side. In models of attention, this phenomenon is postulated to rely on an interaction between ventral and dorsal cortical networks, subtending non-spatial and spatial attentional aspects, respectively. However, the exact neural underpinnings of the interaction between these two networks are still poorly understood. In the present study, we included 80 right-hemispheric patients with subacute stroke (50% women; age range: 24–96), 33 with and 47 without neglect, as assessed by paper–pencil cancellation tests. The patients performed a computerized task in which they were asked to respond as quickly as possible by button-press to central targets, which were either preceded or not preceded by non-spatial, auditory warning tones. Reaction times in the two different conditions were measured. In neglect patients, a warning tone, enhancing activity within the ventral attentional ‘alerting’ network, could boost the reaction (in terms of shorter reaction times) of the dorsal attentional network to a visual stimulus up to the level of patients without neglect. Critically, using voxel-based lesion-symptom mapping analyses, we show that this effect significantly depends on the integrity of the right anterior insula and adjacent inferior frontal gyrus, i.e., right-hemispheric patients with lesions involving these areas were significantly less likely to show shorter reaction times when a warning tone was presented prior to visual target appearance. We propose that the right anterior insula and inferior frontal gyrus are a critical hub through which the ventral attentional network can ‘alert’ and increase the efficiency of the activity of the dorsal attentional network.

Effectiveness of Lateral Auditory Collision Warnings: Should Warnings Be Toward Danger or Toward Safety?

Objective The present study investigated the design of spatially oriented auditory collision-warning signals to facilitate drivers’ responses to potential collisions. Background Prior studies on collision warnings have mostly focused on manual driving. It is necessary to examine the design of collision warnings for safe takeover actions in semi-autonomous driving. Method In a video-based semi-autonomous driving scenario, participants responded to pedestrians walking across the road, with a warning tone presented in either the avoidance direction or the collision direction. The time interval between the warning tone and the potential collision was also manipulated. In Experiment 1, pedestrians always started walking from one side of the road to the other side. In Experiment 2, pedestrians appeared in the middle of the road and walked toward either side of the road. Results In Experiment 1, drivers reacted to the pedestrian faster with collision-direction warnings than with avoidance-direction warnings. In Experiment 2, the difference between the two warning directions became nonsignificant. In both experiments, shorter time intervals to potential collisions resulted in faster reactions but did not influence the effect of warning direction. Conclusion The collision-direction warnings were advantageous over the avoidance-direction warnings only when they occurred at the same lateral location as the pedestrian, indicating that this advantage was due to the capture of attention by the auditory warning signals. Application The present results indicate that drivers would benefit most when warnings occur at the side of potential collision objects rather than the direction of a desirable action during semi-autonomous driving.

Attribution Biases and Trust Development in Physical Human-Machine Coordination: Blaming Yourself, Your Partner or an Unexpected Event

Reading partners’ actions correctly is essential for successful coordination, but interpretation does not always reflect reality. Attribution biases, such as self-serving and correspondence biases, lead people to misinterpret their partners’ actions and falsely assign blame after a surprise, or unexpected event. These biases further influence people’s trust in their partners, including machine partners (Muir, 1987; Madhavan & Wiegmann, 2004). Advances in robotics have allowed for robots to partner with people at work and be treated socially (Young, Hawkins, Sharlin & Igarashi, 2009). However, these advances may interfere with a person’s appropriate calibration of trust in robots (Parasuraman & Miller, 2004). A better understanding of attribution biases in the wake of an unexpected event may shed light on how trust develops in a robot partner. This study was built on a human coordination example to serve as a reference for future human-robot interactions. We posit that attribution biases lead people to blame their partner after experiencing a negative performance outcome, thus lowering their trust in the partner. Sixty participants (30 pairs) were tasked to coordinate with an unfamiliar human partner, to lift a 17.5 lb. box containing a 200ml cup of water filled to the brim, from the floor to a table, as quickly as possible without spilling water. Before the task, participants were told that the pair with the best performance would be rewarded; however, all pairs were told they did not achieve this. Participant pairs were randomly assigned to a surprise condition during which they heard a 250 Hz warning tone, or a baseline condition with no warning tone. Participants in both conditions were told to pause the task as quickly as possible if the warning tone was present. It was unknown to participants when or if a warning tone would occur. To assess participants’ trust in their partner, Muir’s (1987) trust questionnaire was administered twice, once after introducing the task to participants, and again after the coordination task was completed. To capture blame assignment, a scale based on Kim and Hinds (2006) was administered after participants were told they did not achieve the best performance. Results indicate participants were less likely to blame their partners for the negative outcome, compared to blaming themselves or the warning tone itself (in the surprise condition). Next, surprisingly, in the surprise condition, instead of experiencing a decrease of trust in a partner after the negative outcome, there was a significant increase in trust in their partners. No significant difference in trust was found in the baseline condition. Finally, results also indicate that initial trust in a partner is a significant predictor for how people assign blame. In general, the effects of attribution biases were not observed in the present study. Friendliness may be a factor in people’s assignment of blame; although participants were unfamiliar with one another, all participants were students at the same university. Second, shared experience during the surprise condition, including the chance to assess their partner’s behaviors in response to the warning tone, may have been a catalyst for increased trust in a partner. It is important to note that although physical differences between participants were not evaluated in this study, height may be a potential confounding factor in this task. These findings enlighten our understanding of physical human-robot coordination scenarios and trust in a partner.

Driver Responses to Augmented Reality Warnings and Alternatives at Urban Signalized Intersections

This study examined an augmented reality warning system that highlighted threats with a yellow arrow pointing towards the potential threat and a red bar below it. Sixteen drivers drove a fixed base driving simulator in a world with 61 intersections, 10 of which contained threats. Threats could appear from any direction, and go straight or turn. Each subject completed 3 test blocks of those intersections in a different random order – no warning, a warning tone, or a warning tone accompanied by the augmented reality warning. Warnings led to significantly fewer crashes (14 for augmented reality, 24 for warning tone, 30 for no warning). When compared to no warnings, augmented reality warnings also led to shorter response times (23%/35% less, depending upon how RT was measured), greater maximum brake pressures (42%) and greater maximum decelerations (18%). These results indicate that augmented reality warnings can be beneficial to drivers.

The Content of IMF Staff Reports for Euro Area Countries

This chapter analyzes the tone and information content of the two external policy reports of the Internal Monetary Fund (IMF), the IMF Article IV Staff Reports, and Executive Board Assessments for Euro area countries. In particular, the researchers create a tone measure denoted WARNING based on the existing DICTION 5.0 Hardship dictionary. This study finds that in the run-up to the current credit crises, average WARNING tone levels of Staff Reports for Slovenia, Luxembourg, Greece, and Malta are one standard deviation above the EMU sample mean; and for Spain and Belgium, they are one standard deviation below the mean value. Furthermore, on average for Staff Reports over the period 2005-2007, there are insignificant differences between the EMU sample mean and Staff Reports’ yearly averages. Researchers find the presence of a significantly increased level of WARNING tone in 2006 (compared to the previous year) for the IMF Article IV Staff Reports. There is also a systematic bias of WARNING scores for Executive Board Assessments versus WARNING scores for the Staff Reports.

Are Individual Differences in Absentmindedness Correlated with Individual Differences in Attention?

We administered the Cognitive Failures Questionnaire (CFQ) and one of two versions of the Attention Network Test (ANT) to 200 participants. Orthogonal subtraction scores based on performance (reaction time and error rate) from selected conditions of the ANT provided measures of the efficacy of three attention components: alerting, orienting, and executive control, while the total CFQ score provided a global measure of absentmindedness. Executive control was not associated with the CFQ in either experiment. When alertness was generated by a warning tone, greater alerting effects in reaction time were associated with higher CFQ scores (greater absentmindedness). The orienting effects in accuracy obtained from the two versions of the ANT varied with absentmindedness in opposite directions, suggesting that these two tests tap different aspects of orienting.