Working alone or in the presence of others: exploring social facilitation in baggage X-ray security screening tasks

The human-factors' challenges of (tele)drivers of Autonomous Vehicles

Autonomous capabilities, including Autonomous Vehicle (AV) technology, aim to reduce human effort, extend capabilities, and enhance safety. While AVs offer societal benefits, human intervention remains necessary, especially in complex situations. As communication technology advances, human intervention is possible from remote sites. In such remote locations, highly skilled tele-drivers (TEDs) are ready to face situations too complicated for the AV. However, current work still needs a comprehensive mapping of the challenges that TEDs would face. Some of these challenges are shared with IVDs but may have stronger or weaker effects on the remote driver's ability to maintain safety. Other challenges, such as limited situational awareness of the road scene, the indirect experience of vehicle motion, and communication latency, are unique to TEDs. We assess the challenges, comparing their impact on TEDs versus IVDs, and explore technological countermeasures aimed at mitigating specific challenges encountered by TEDs. Lastly, we identified knowledge gaps and areas lacking understanding in the literature, highlighting avenues for future research and practical implications for practitioners.

Social facilitation effects in online coaction: the moderating role of social comparison direction

Online and face-to-face coactions are widely used work organization modes. This study aims to investigate the effect of social comparison direction on task performance when people coact online. A total of 40 individuals were recruited to participate in a 2 (coaction type: online and face to face) × 3 (social comparison direction: upward, downward and no comparison) × 2 (phase: pre-comparison and post-comparison) within-subject experiment. The participants performed visual search tasks while their response time and search accuracy rates were measured. Results showed that the participants were reported to perform faster when they coacted online than face to face. The upward comparison led to a stronger social facilitation effect than the downward and no comparison directions, either in online or face-to-face coaction. These findings provide practical implications in the design of coaction modes for groups and teams working remotely.

An EEG-Based Investigation of the Effect of Perceived Observation on Visual Memory in Virtual Environments

The presence of external observers has been shown to affect performance on cognitive tasks, but the parameters of this impact for different types of tasks and the underlying neural dynamics are less understood. The current study examined the behavioral and brain activity effects of perceived observation on participants’ visual working memory (VWM) in a virtual reality (VR) classroom setting, using the task format as a moderating variable. Participants (n = 21) were equipped with a 57-channel EEG cap, and neural data were collected as they completed two VWM tasks under two observation conditions (observed and not observed) in a within-subjects experimental design. The “observation” condition was operationalized through the addition of a static human avatar in the VR classroom. The avatar’s presence was associated with a significant effect on extending the task response time, but no effect was found on task accuracy. This outcome may have been due to a ceiling effect, as the mean participant task scores were quite high. EEG data analysis supported the behavioral findings by showing consistent differences between the no-observation and observation conditions for one of the VWM tasks only. These neural differences were identified in the dorsolateral prefrontal cortex (dlPFC) and the occipital cortex (OC) regions, with higher theta-band activity occurring in the dlPFC during stimulus encoding and in the OC during response selection when the “observing” avatar was present. These findings provide evidence that perceived observation can inhibit performance during visual tasks by altering attentional focus, even in virtual contexts.

Peer Presence Effects on Eye Movements and Attentional Performance

"Social facilitation" refers to the enhancement or impairment of performance engendered by the mere presence of others. It has been demonstrated for a diversity of behaviors. This study assessed whether it also concerns attention and eye movements and if yes, which decision-making mechanisms it affects. Human volunteers were tested in three different tasks (saccades, visual search, and continuous performance) either alone or in the presence of a familiar peer. The results failed to reveal any significant peer influence on the visual search and continuous performance tasks. For saccades, by contrast, they showed a negative or positive peer influence depending on the complexity of the testing protocol. Pro-and anti-saccades were both inhibited when pseudorandomly mixed, and both facilitated when performed separately. Peer presence impaired or improved reaction times, i.e., the speed to initiate the saccade, as well as peak velocity, i.e., the driving force moving the eye toward the target. Effect sizes were large, with Cohen's d-values ranging for reaction times (RTs) from 0.50 to 0.95. Analyzing RT distributions using the LATER (Linear Approach to Threshold with Ergodic Rate) model revealed that social inhibition of pro- and anti-saccades in the complex protocol was associated with a significant increase in the rate of rise. The present demonstration that the simple presence of a familiar peer can inhibit or facilitate saccades depending on task difficulty strengthens a growing body of evidence showing social modulations of eye movements and attention processes. The present lack of effect on visual search and continuous performance tasks contrasts with peer presence effects reported earlier using similar tasks, and future studies are needed to determine whether it is due to an intermediate level of difficulty maximizing individual variability. Together with an earlier study of the social inhibition of anti-saccades also using the LATER model, which showed an increase of the threshold, the present increase of the rate of rise suggests that peer presence can influence both the top-down and bottom-up attention-related processes guiding the decision to move the eyes.

Detection measures for visual inspection of X-ray images of passenger baggage

In visual inspection tasks, such as airport security and medical screening, researchers often use the detection measures d' or A' to analyze detection performance independent of response tendency. However, recent studies that manipulated the frequency of targets (target prevalence) indicate that da with a slope parameter of 0.6 is more valid for such tasks than d' or A'. We investigated the validity of detection measures (d', A', and da) using two experiments. In the first experiment, 31 security officers completed a simulated X-ray baggage inspection task while response tendency was manipulated directly through instruction. The participants knew half of the prohibited items used in the study from training, whereas the other half were novel, thereby establishing two levels of task difficulty. The results demonstrated that for both levels, d' and A' decreased when the criterion became more liberal, whereas da with a slope parameter of 0.6 remained constant. Eye-tracking data indicated that manipulating response tendency affected the decision component of the inspection task rather than search errors. In the second experiment, 124 security officers completed another simulated X-ray baggage inspection task. Receiver operating characteristic (ROC) curves based on confidence ratings provided further support for da, and the estimated slope parameter was 0.5. Consistent with previous findings, our results imply that d' and A' are not valid measures of detection performance in X-ray image inspection. We recommend always calculating da with a slope parameter of 0.5 in addition to d' to avoid potentially wrong conclusions if ROC curves are not available.

Independent Coactors May Improve Performance and Lower Workload: Viewing Vigilance Under Social Facilitation

OBJECTIVE

The purpose of the present study was to examine the effects of an independent coactor on vigilance task performance. It was hypothesized that the presence of an independent coactor would improve performance in terms of the proportion of false alarms while also increasing perceived workload and stress.

BACKGROUND

Vigilance, or the ability to maintain attention for extended periods, is of great interest to human factors psychologists. Substantial work has focused on improving vigilance task performance, typically through motivational interventions. Of interest to vigilance researchers is the application of social facilitation as a means of enhancing vigilance. Social facilitation seeks to explain how social presence may improve performance.

METHOD

A total of 100 participants completed a 24-min vigil either alone or in the presence of an independent (confederate) coactor. Participants completed measures of perceived workload and stress.

RESULTS

The results indicated that performance (i.e., proportion of false alarms) was improved for those who completed the vigil in the presence of an independent coactor. Interestingly, perceived workload was actually lower for those who completed the vigil in the presence of an independent coactor, although perceived stress was not affected by the manipulation.

CONCLUSION

Authors of future research should extend these findings to other forms of social facilitation and examine vigilance task performance in social contexts in order to determine the utility of social presence for improving vigilance.

APPLICATION

The use of coactors may be an avenue for organizations to consider utilizing to improve performance because of its relative cost-effectiveness and easy implementation.

Visual search tasks: measurement of dynamic visual lobe and relationship with display movement velocity

Visual lobe is a useful tool for predicting visual search performance. Up till now, no study has focused on dynamic visual lobe. This study developed a dynamic visual lobe measurement system (DVLMS) that could effectively map dynamic visual lobe and calculate visual lobe shape indices. The effects of display movement velocity on lobe shape indices were examined under four velocity conditions: 0, 4, 8 and 16 deg/s. In general, with the increase of display movement velocity, visual lobe area and perimeter became smaller, whereas lobe shape roundness, boundary smoothness, symmetry and regularity deteriorated. The elongation index was not affected by velocity. Regression analyses indicated that display movement velocity was important in determining dynamic visual lobe shape indices. Dynamic visual lobe provides another option for better understanding dynamic vision, in addition to dynamic visual acuity. Findings of this study can provide guidelines for analysing and designing dynamic visual tasks. Practitioner Summary: Dynamic visual lobe is important in reflecting the visual ability of searching for a moving target. We developed a dynamic visual lobe measurement system (DVLMS) and examined display movement velocity's effects on lobe shape. Findings revealed that velocity was a key factor affecting dynamic visual lobe shape indices.

Influence of social presence on eye movements in visual search tasks

This study employed an eye-tracking technique to investigate the influence of social presence on eye movements in visual search tasks. A total of 20 male subjects performed visual search tasks in a 2 (target presence: present vs. absent) × 2 (task complexity: complex vs. simple) × 2 (social presence: alone vs. a human audience) within-subject experiment. Results indicated that the presence of an audience could evoke a social facilitation effect on response time in visual search tasks. Compared with working alone, the participants made fewer and shorter fixations, larger saccades and shorter scan path in simple search tasks and more and longer fixations, smaller saccades and longer scan path in complex search tasks when working with an audience. The saccade velocity and pupil diameter in the audience-present condition were larger than those in the working-alone condition. No significant change in target fixation number was observed between two social presence conditions. Practitioner Summary: This study employed an eye-tracking technique to examine the influence of social presence on eye movements in visual search tasks. Results clarified the variation mechanism and characteristics of oculomotor scanning induced by social presence in visual search.

Gender composition mediates social facilitation effect in co-action condition

Working with co-actors is a common work-organization mode. Whether the presence of opposite-sex co-actors (OCs) can induce social facilitation effect and how an actor's performance is influenced by the gender composition of co-actors remain unknown. The present study aims to examine the influence of the gender composition of co-actors on the intensity of the social facilitation effect. In Experiment 1, participants performed visual search tasks alone and in six co-action conditions with varying gender compositions. In Experiment 2, the participants performed modular arithmetic tasks in three conditions with electroencephalogram activity recorded and salivary cortisol measured: alone, with a same-sex co-actor (SC), and with an OC. Results indicated that the social facilitation effect was stronger in the presence of OCs than in the presence of only SCs. The intensities of social facilitation effect resulting from the varying gender composition of co-actors were obtained and compared. A participant's power of alpha band was lower, whereas power of beta band and normalised cortisol level were higher in the presence of an OC than in the presence of an SC. These findings provide insights into the influencing mechanisms of gender composition on the intensity of the social facilitation effect in the co-action condition.

Examining social facilitation in vigilance: a hit and a miss

Vigilance is the ability of an observer to maintain attention for extended periods of time; however, performance tends to decline with time on watch, a pattern referred to as the vigilance decrement. Previous research has focused on factors that attenuate the decrement; however, one factor rarely studied is the effect of social facilitation. The purpose for the present investigation was to determine how different types of social presence affected the performance, workload and stress of vigilance. It was hypothesised that the presence of a supervisory figure would increase overall performance, but may occur at the cost of increased workload and stress. Results indicated that the per cent of false alarm and response times decreased in the presence of a supervisory figure. Using social facilitation in vigilance tasks may thus have positive, as well as, negative effects depending on the dependent measure of interest and the role of the observer. Practitioner Summary: Social facilitation has rarely been examined in the context of vigilance, even though it may improve performance. Vigilance task performance was examined under social presence. The results of the present study indicated that false alarms and response times decreased in the social presence of a supervisory figure, thus improving performance.

Fluctuations of the experience of togetherness within the team over time: task-cohesion and shared understanding throughout a sporting regular season

Based on a diagnosis action research design, the present study assessed the fluctuations of the team experience of togetherness. Reported experiences of 12 basketball team members playing in the under-18 years old national championship were studied during a four-month training and competitive period. Time series analysis (Auto-Regressive Integrated Moving Average procedures) served to describe temporal properties of the way in which the fluctuations of task-cohesion and shared understanding were step-by-step experienced over time, respectively. Correlations, running-correlations and cross-lagged correlations were used to describe the temporal links that governed the relationships between both phenomena. The results indicated that the task-cohesion dimensions differed mainly for shared understanding dynamics in that their time fluctuations were not embedded in external events, and that the variations in shared understanding tend to precede 'individual attractions to the task' variations with seven team practical sessions. This study argues for further investigation of how 'togetherness' is experienced alternatively as a feeling of cohesion or shared understanding. Practitioner Summary: The present action research study investigated the experience that the team members have to share information during practice, and the subsequent benefices on team cohesion. Results call for specific interventions that make team members accept the fluctuating nature of team phenomena, to help them maintaining their daily efforts.

Risk factors and visual fatigue of baggage X-ray security screeners: a structural equation modelling analysis

This study identified the risk factors influencing visual fatigue in baggage X-ray security screeners and estimated the strength of correlations between those factors and visual fatigue using structural equation modelling approach. Two hundred and five X-ray security screeners participated in a questionnaire survey. The result showed that satisfaction with the VDT's physical features and the work environment conditions were negatively correlated with the intensity of visual fatigue, whereas job stress and job burnout had direct positive influences. The path coefficient between the image quality of VDT and visual fatigue was not significant. The total effects of job burnout, job stress, the VDT's physical features and the work environment conditions on visual fatigue were 0.471, 0.469, -0.268 and -0.251 respectively. These findings indicated that both extrinsic factors relating to VDT and workplace environment and psychological factors including job burnout and job stress should be considered in the workplace design and work organisation of security screening tasks to reduce screeners' visual fatigue. Practitioner Summary: This study identified the risk factors influencing visual fatigue in baggage X-ray security screeners and estimated the strength of correlations between those factors and visual fatigue. The findings were of great importance to the workplace design and the work organisation of security screening tasks to reduce screeners' visual fatigue.