Evaluating Driver Features for Cognitive Distraction Detection and Validation in Manual and Level 2 Automated Driving.

OBJECTIVE: This study aimed to investigate the impacts of feature selection on driver cognitive distraction (CD) detection and validation in real-world nonautomated and Level 2 automated driving scenarios. BACKGROUND: Real-time driver state monitoring is critical to promote road user safety. METHOD: Twenty-four participants were recruited to drive a Tesla Model S in manual and Autopilot modes on the highway while engaging in the N-back task. In each driving mode, CD was classified by the random forest algorithm built on three "hand-crafted" glance features (i.e., percent road center [PRC], the standard deviation of gaze pitch, and yaw angles), or through a large number of features that were transformed from the output of a driver monitoring system (DMS) and other sensing systems. RESULTS: In manual driving, the small set of glance features was as effective as the large set of machine-generated features in terms of classification accuracy. Whereas in Level 2 automated driving, both glance and vehicle features were less sensitive to CD. The glance features also revealed that the misclassified driver state was the result of the dynamic fluctuations and individual differences of cognitive loads under CD. CONCLUSION: Glance metrics are critical for the detection and validation of CD in on-road driving. APPLICATIONS: The paper suggests the practical value of human factors domain knowledge in feature selection and ground truth validation for the development of driver monitoring technologies.

Response Complexity Reduces Errors on a Response Inhibition Task.

OBJECTIVE: The purpose of this investigation was to elucidate the role of button-response complexity to targets in a response inhibition task. BACKGROUND: Response inhibition is the ability to correctly inhibit an overt response to a target. The U.S. military is actively pursuing development of armed, combat robots as a force multiplier, which may present challenges to operators of combat robots in the form of response inhibition errors. METHOD: A total of 15 participants completed two 51-min versions of a modified sustained attention to response task (SART). Participants were outfitted with an electrocardiogram to index heart-rate variability and completed the NASA-Task Load Index (NASA-TLX) to index workload. RESULTS: The results demonstrated that the complex SART reduced errors of commission (4%) and slowed response times (874 ms) to correct Go targets relative to the simple SART (14%, 739 ms). The NASA-TLX did not show differences between the modified SARTs; however, heart-rate variability did demonstrate that Soldiers had an increased autonomic stress response to the complex SART. CONCLUSION: Increasing the behavioral response requirement during a response inhibition task can decrease errors of commission; however, it comes at the cost of slower response times to target stimuli. Heart-rate variability may provide better insight into objective workload relative to subjective measures. APPLICATION: The use of complex behavioral responses may provide a viable option to reduce potential "friendly fire" or collateral damage by Soldiers remotely engaging a target-rich environment.

Visual Feedback Attenuates Mean Concentric Barbell Velocity Loss and Improves Motivation, Competitiveness, and Perceived Workload in Male Adolescent Athletes.

Weakley, JJS, Wilson, KM, Till, K, Read, DB, Darrall-Jones, J, Roe, GAB, Phibbs, PJ, and Jones, B. Visual feedback attenuates mean concentric barbell velocity loss and improves motivation, competitiveness, and perceived workload in male adolescent athletes. J Strength Cond Res 33(9): 2420-2425, 2019-It is unknown whether instantaneous visual feedback of resistance training outcomes can enhance barbell velocity in younger athletes. Therefore, the purpose of this study was to quantify the effects of visual feedback on mean concentric barbell velocity in the back squat and to identify changes in motivation, competitiveness, and perceived workload. In a randomized-crossover design (Feedback vs. Control), feedback of mean concentric barbell velocity was or was not provided throughout a set of 10 repetitions in the barbell back squat. Magnitude-based inferences were used to assess changes between conditions, with almost certainly greater differences in mean concentric velocity between the Feedback (0.70 ± 0.04 m·s) and Control (0.65 ± 0.05 m·s) observed. In addition, individual repetition mean concentric velocity ranged from possibly (repetition number 2: 0.79 ± 0.04 vs. 0.78 ± 0.04 m·s) to almost certainly (repetition number 10: 0.58 ± 0.05 vs. 0.49 ± 0.05 m·s) greater when provided feedback, whereas almost certain differences were observed in motivation, competitiveness, and perceived workload, respectively. Providing adolescent male athletes with visual kinematic information while completing resistance training is beneficial for the maintenance of barbell velocity during a training set, potentially enhancing physical performance. Moreover, these improvements were observed alongside increases in motivation, competitiveness, and perceived workload providing insight into the underlying mechanisms responsible for the performance gains observed. Given the observed maintenance of barbell velocity during a training set, practitioners can use this technique to manipulate training outcomes during resistance training.

Go-stimuli proportion influences response strategy in a sustained attention to response task.

The sustained attention to response task (SART) usefulness as a measure of sustained attention has been questioned. The SART may instead be a better measure of other psychological processes and could prove useful in understanding some real-world behaviours. Thirty participants completed four Go/No-Go response tasks much like the SART, with Go-stimuli proportions of .50, .65, .80 and .95. As Go-stimuli proportion increased, reaction times decreased while both commission errors and self-reported task-related thoughts increased. Performance measures were associated with task-related thoughts but not task-unrelated thoughts. Instead of faster reaction times and increased commission errors being due to absentmindedness or perceptual decoupling from the task, the results suggested participants made use of two competing response strategies, in line with a response strategy or response inhibition perspective of SART performance. Interestingly, performance measures changed in a nonlinear manner, despite the linear Go proportion increase. A threshold may exist where the prepotent motor response becomes more pronounced, leading to the disproportionate increase in response speed and commission errors. This research has implications for researchers looking to employ the SART and for more applied contexts where the consequences of response inhibition failures can be serious.

The effect of task-relevant and irrelevant anxiety-provoking stimuli on response inhibition.

The impact of anxiety-provoking stimuli on the Sustained Attention to Response Task (SART; Robertson, Manly, Andrade, Baddeley, & Yiend, 1997), and response inhibition more generally, is currently unclear. Participants completed four SARTs embedded with picture stimuli of two levels of emotion (negative or neutral) and two levels of task-relevance (predictive or non-predictive of imminent No-Go stimuli). Negative pictures had a small but detectable adverse effect on performance regardless of their task-relevance. Overall, response times and rates of commission errors were more dependent upon the predictive value (relevance) of the pictures than their attention-capturing nature (i.e., negative valence). The findings raise doubt over whether anxiety improves response inhibition, and also lend support to a response strategy perspective of SART performance, as opposed to a mindlessness or mind-wandering explanation.

The effects of warning cues and attention-capturing stimuli on the sustained attention to response task.

Performance on the sustained attention to response task (SART) is often characterized by a speed-accuracy trade-off, and SART performance may be influenced by strategic factors (Head and Helton Conscious Cogn 22: 913-919, 2013). Previous research indicates a significant difference between reliable and unreliable warning cues on response times and errors (commission and omission), suggesting that SART tasks are influenced by strategic factors (Helton et al. Conscious Cogn 20: 1732-1737, 2011; Exp Brain Res 209: 401-407, 2011). With regards to warning stimuli, we chose to use cute images (exhibiting infantile features) during a SART, as previous literature indicates cute images cause participants to engage attention. If viewing cute things makes the viewer exert more attention than normal, then exposure to cute stimuli during the SART should improve performance if SART performance is a measure of perceptual coupling. Reliable warning cues were shown to reduce both response time and errors of commission, and increase errors of omission, relative to unreliable warning cues. Cuteness of the warning stimuli, however, had no significant effect on SART performance. These results suggest the importance of strategic factors in SART performance, not increased attention, and add to the growing literature which suggests the SART is not a good measure of sustained attention, vigilance or perceptual coupling.

Spider stimuli improve response inhibition.

Anxiety can have positive effects on some aspects of cognition and negative effects on others. The current study investigated whether task-relevant anxiety could improve people's ability to withhold responses in a response inhibition task. Sixty-seven university students completed a modified and an unmodified version of the Sustained Attention to Response Task (SART; Robertson, Manly, Andrade, Baddeley, & Yiend, 1997) and provided subjective measures of arousal and thoughts. Anxiety appeared to improve participants' ability to withhold responses. Further, participants' performance was consistent with a motor response inhibition perspective rather than a mind-wandering perspective of SART commission error performance. Errors of commission were associated with response times (speed-accuracy trade-off) as opposed to task-unrelated thoughts. Task-related thoughts were associated with the speed-accuracy trade-off. Conversely task-unrelated thoughts showed an association with errors of omission, suggesting this SART metric could be an indicator of sustained attention. Further investigation of the role of thoughts in the SART is warranted.

Friendly Fire and the Sustained Attention to Response Task.

OBJECTIVE: We investigated whether losses of inhibitory control could be responsible for some friendly-fire incidents. BACKGROUND: Several factors are commonly cited to explain friendly-fire incidents, but failure of inhibitory control has not yet been explored. The Sustained Attention to Response Task (SART) could be a valid model for inhibition failures in some combat scenarios. METHOD: Participants completed small-arms simulations using near infrared emitter guns, confronting research assistants acting as friends or foes. In Experiment 1, seven participants completed three conditions with three different proportions of foes (high, medium, low). In Experiment 2, 13 participants completed high-foe (high-go) and low-foe (low-go) versions of a small-arms simulation as well as comparative computer tasks. RESULTS: Participants made more friendly-fire errors (errors of commission) when foe proportion was high. A speed-accuracy trade-off was apparent, with participants who were faster to fire on foes also more likely to accidentally shoot friends. When foe proportion was higher, response times to foe stimuli were faster, and subjective workload ratings were higher. CONCLUSION: Failures of inhibitory control may be responsible for some friendly-fire incidents and the SART could be a suitable empirical model for some battlefield environments. The effect appears to be disproportionately greater at higher foe proportions. The exact nature of performance reductions associated with high-foe proportions requires further investigation. APPLICATION: The SART may be a useful model of friendly-fire scenarios. It could be used to indicate a soldier's likelihood to commit a friendly-fire mistake and to identify high-risk environments.

Prolonging the response movement inhibits the feed-forward motor program in the sustained attention to response task.

Despite widespread use in clinical and experimental contexts, debate continues over whether or not the Sustained Attention to Response Task (SART) successfully measures sustained attention. Altering physical aspects of the response movement required to SART stimuli may help identify whether performance is a better measure of perceptual decoupling, or response strategies and motor inhibition. Participants completed a SART where they had to manually move a mouse cursor to respond to stimuli, and another SART where this extra movement was not required, as in a typical SART. Additionally, stimuli were located at either a close or a far distance away. Commission errors were inversely related to distance in the manual movement condition, as the farther distance led to longer response times which gave participants more time to inhibit prepotent responses and thus prevent commission errors. Self-reported measures of mental demand and fatigue suggested there were no differences in mental demands between the manual and automatic condition; instead the differences were primarily in physical demands. No differences were found for task-unrelated thoughts between the manual and automatic condition. The movement effect combined with participants' subjective reports are evidence for time dependent action stopping, not greater cognitive engagement. These findings support a response strategy perspective as opposed to a perceptual decoupling perspective, and have implications for authors considering using the SART. Applied implications of this research are also discussed.

A functional near-infrared spectroscopy study of the effects of configural properties on sustained attention.

Forty-five participants performed a vigilance task during which they were required to respond to a critical signal at a local feature level, while the global display was altered between groups (either a circle, a circle broken apart and reversed, or a reconnected figure). The shape in two of the groups formed a configurative whole (the circle and reconnected conditions), while the remaining shape had no complete global element (broken circle). Performance matched the results found in the previous experiments using this stimulus set, where a configural superiority effect was found to influence accuracy over time. Physiological data, measured using functional near-infrared spectroscopy, revealed elevated activation in the right pre-frontal cortex compared to the left pre-frontal cortex during the task. Additionally, bilateral activation was found in the conditions that formed configurative wholes, while hemispheric differences over time were found in the condition that did not. These findings suggest that configural aspects of stimuli may explain why non-typical laterality effects have been found in similar research.

Prior Mental Fatigue Impairs Marksmanship Decision Performance.

Purpose: Mental fatigue has been shown to impair subsequent physical performance in continuous and discontinuous exercise. However, its influence on subsequent fine-motor performance in an applied setting (e.g., marksmanship for trained soldiers) is relatively unknown. The purpose of this study was to investigate whether prior mental fatigue influences subsequent marksmanship performance as measured by shooting accuracy and judgment of soldiers in a live-fire scenario. Methods: Twenty trained infantry soldiers engaged targets after completing either a mental fatigue or control intervention in a repeated measure design. Heart rate variability and the NASA-TLX were used to gauge physiological and subjective effects of the interventions. Target hit proportion, projectile group accuracy, and precision were used to measure marksmanship accuracy. Marksmanship accuracy was assessed by measuring bullet group accuracy (i.e., how close a group of shots are relative to center of mass) and bullet group precision (i.e., how close are each individual shot to each other). Additionally, marksmanship decision accuracy (correctly shooting vs. correctly withholding shot) when engaging targets was used to examine marksmanship performance. Results: Soldiers rated the mentally fatiguing task (59.88 ± 23.7) as having greater mental workload relative to the control intervention [31.29 ± 12.3, t(19) = 1.72, p < 0.001]. Additionally, soldiers completing the mental fatigue intervention (96.04 ± = 37.1) also had lower time-domain (standard deviation of normal to normal R-R intervals) heart rate variability relative to the control [134.39 ± 47.4, t(18) = 3.59, p < 0.001]. Projectile group accuracy and group precision failed to show differences between interventions [t(19) = 0.98, p = 0.34, t(19) = 0.18, p = 0.87, respectively]. Marksmanship decision errors significantly increased after soldiers completed the mental fatigue intervention (48% ± 22.4) relative to the control intervention [M = 32% ± 79.9, t(19) = 4.39, p < 0.001]. There was a significant negative correlation between shooting response time and errors of commission (r = -0.61; p = 0.004) when preceded by the mental fatigue intervention, but not the control (r = -0.31; p = 0.17). Conclusion: The mental fatigue intervention was successful in eliciting fatigue which was supported subjectively and objectively. Marksmanship judgment performance is significantly reduced when soldiers are mentally fatigued, although shot accuracy is not.

Cognitive engineering.

Cognitive engineering is the application of cognitive psychology and related disciplines to the design and operation of human-machine systems. Cognitive engineering combines both detailed and close study of the human worker in the actual work context and the study of the worker in more controlled environments. Cognitive engineering combines multiple methods and perspectives to achieve the goal of improved system performance. Given the origins of experimental psychology itself in issues regarding the design of human-machine systems, cognitive engineering is a core, or fundamental, discipline within academic psychology. WIREs Cogn Sci 2013, 4:17-31. doi: 10.1002/wcs.1204 CONFLICT OF INTEREST: The authors declare no conflict of interest. For further resources related to this article, please visit the WIREs website.