Recalibration in functional perceptual-motor tasks: A systematic review

Examining the Effects of Dynamic and Isometric Resistance Training on Knee Joint Kinetics During Unplanned Sidesteps in Elite Female Athletes

ABSTRACT

Kadlec, D, Jordan, MJ, Alderson, J, and Nimphius, S. Examining the effects of dynamic and isometric resistance training on knee joint kinetics during unplanned sidesteps in elite female athletes. J Strength Cond Res XX(X): 000-000, 2024-The purpose of this study was to examine the effects of a 4-week block of isometric (isometricRT) and dynamic resistance training (dynamicRT) on kinetic variables associated with anterior cruciate ligament (ACL) injury risk during unplanned sidesteps in elite female athletes. Twenty-one elite female athletes competing for a women's international rugby union team were recruited with 15 (n = 15; age: 23.4 ± 4.7 years; 170.7 ± 8.4 cm; 84.4 ± 15.4 kg) completing assessment of knee flexion moment, knee valgus moment (KVM), knee internal rotation moment (KIRM), knee joint power during unplanned sidesteps, and lower limb strength before and after a 4-week intervention. Linear mixed effects models and one-dimensional statistical parametric mapping assessed the effect of the interventions. Statistical significance was set at α = 0.05. Postintervention the isometricRT group revealed reduced peak KVM during early stance (p = 0.04) while the dynamicRT group decreased peak KIRM (p < 0.01) and KIRM over 8.8-86.6% (p < 0.01) and 96.9-98.5% (p = 0.047). An exploratory combined group analysis revealed reductions in KVM over 7.9-21.8% (p = 0.002) and in KIRM over 8.3-90.5% (p < 0.01) and 96.2-98.5% (p = 0.046). Most lower limb isometric and dynamic strength measures increased after both resistance training interventions. Overall, both groups increased lower-body maximum strength while reducing kinetic knee joint variables associated with ACL injury risk during unplanned sidesteps. These results highlight the importance of increasing single-joint and multijoint strength in female athletes to mitigate the mechanical knee joint demands during sidestepping.

Jumping and leaping estimations using optic flow

Optic flow provides information on movement direction and speed during locomotion. Changing the relationship between optic flow and walking speed via training has been shown to influence subsequent distance and hill steepness estimations. Previous research has shown that experience with slow optic flow at a given walking speed was associated with increased effort and distance overestimation in comparison to experiencing with fast optic flow at the same walking speed. Here, we investigated whether exposure to different optic flow speeds relative to gait influences perceptions of leaping and jumping ability. Participants estimated their maximum leaping and jumping ability after exposure to either fast or moderate optic flow at the same walking speed. Those calibrated to fast optic flow estimated farther leaping and jumping abilities than those calibrated to moderate optic flow. Findings suggest that recalibration between optic flow and walking speed may specify an action boundary when calibrated or scaled to actions such as leaping, and possibly, the manipulation of optic flow speed has resulted in a change in the associated anticipated effort for walking a prescribed distance, which in turn influence one's perceived action capabilities for jumping and leaping.

Effects of arm-support exoskeletons on pointing accuracy and movement

Exoskeletons are wearable devices that support or augment users' physical abilities. Previous studies indicate that they reduce the physical demands of repetitive tasks such as those involving heavy material handling, work performed with arms elevated, and the use of heavy tools. However, there have been concerns about exoskeletons hindering movement and reducing its precision. To this end, the current study investigated how proprioception enables people to point to targets in a blindfolded, repetitive pointing task, and their ability to recalibrate their pointing movement based on visual feedback during an intervening calibration phase, both with and without an arm-support exoskeleton. On each trial, participants were instructed to follow a 40 BPM metronome to point six times alternating between two target points placed either on a vertical or horizontal line. Within a trial, each pointing movement alternated between flexion and extension. Results indicate that participants' average pointing error increased by 4% when they wore an exoskeleton, compared to when they did not. The average pointing error was 12% lower when the target points were aligned vertically as compared to horizontally. It was also observed that the average pointing error was 14% lower during flexion as compared to extension movement. Surprisingly, accuracy did not improve in the post-test as compared to the pre-test phase, likely due to accuracy being high from the beginning. Participants' movement dynamics were analyzed using Recurrence Quantification Analysis. It was found that movements were less deterministic (1% reduction in percentage of determinism) and less stable (13.6% reduction in average diagonal line length on the recurrence plot) when they wore the exoskeleton as compared to when they did not. These results have implications on the design of arm-support exoskeletons and for facilitating their integration into the natural motor synergies in humans.

A systematic review of perception of affordances for the person-plus-object system

Human behavior often involves the use of an object held by or attached to the body, which modifies the individual's action capabilities. Moreover, most everyday behaviors consist of sets of behaviors that are nested over multiple spatial and temporal scales, which require perceiving and acting on nested affordances for the person-plus-object system. This systematic review investigates how individuals attune to information about affordances involving the person-plus-object system and how they (re)calibrate their actions to relevant information. We analyzed 71 articles-34 on attunement and 37 on (re)calibration with healthy participants-that experimentally investigated the processes involved in the perception of affordances for the person-plus-object system (including attunement, calibration, and recalibration). With respect to attunement, objects attached to the body create a multiplicity of affordances for the person-plus-object system, and individuals learned (1) to detect information about affordances of (and for) the person-plus-object system in a task and (2) to choose whether, when, and how to exploit those affordances to perform that task. Concerning (re)calibration, individuals were able (1) to quickly scale their actions in relation to the (changed) action capabilities of the person-plus-object system and (2) to perceive multiple functionally equivalent ways to exploit the affordances of that system, and these abilities improved with practice. Perceiving affordances for the person-plus-object system involves learning to detect the information about such affordances (attunement) and the scaling of behaviors to such information (calibration). These processes imply a general ability to incorporate an object attached to the body into an integrated person-plus-object system.

An examination of perceptual-motor recalibration in a 1-vs-1 anticipation test

This study examined the processes of perceptual-motor calibration/recalibration of defensive football players in a 1-vs-1 scenario. Ankle weights were used to reduce the acceleration capabilities of players performing an anticipation test, with the aim being to examine the player's response to the disturbance in terms of when movement was initiated and the impact on the mechanisms that underpinned anticipation, namely gaze behaviour. The ankle weights disturbed the perceptual-motor system and players initiated movement significantly earlier in the 1-vs-1 anticipation test. Analyses of perceptual-motor calibration/recalibration revealed that players acted closer to their maximal action capabilities prior to the addition of ankle weights, which negatively influenced the scaling of action capabilities. Moreover, players were unable to recalibrate whilst wearing ankle weights. However, following the withdrawal of the ankle weights, players were able to recalibrate within 11-15 trials. Players did not adapt gaze behaviour as a result of the disturbance being placed on the perceptual-motor system, but task familiarization resulted in more efficient eye movements. The results of this study show the importance of providing players the opportunity to "scale" action to perceptual information.

Coaching and talent development in esports: a theoretical framework and suggestions for future research

Esports is a growing phenomenon that is capturing the attention of individuals worldwide, and has grown to provide professional and lucrative careers for those who reach the upper echelons. One question that arises, is how esports athletes develop the necessary skills required to improve and compete. This perspective piece opens the door to skill acquisition within esports and how research through an ecological approach can benefit researchers and practitioners as they understand the various perception-action couplings and decision-making challenges faced by esports athletes. We will identify and discuss what constraints look like in esports, the role of affordances, and theorize the implementation of a constraints-led approach in contrasting esports genres. As esports is technology-heavy in nature and generally sedentary, the use of eye-tracking technology is argued to represent an effective method to better understand perceptual attunement between individuals and teams. Future research into skill acquisition in esports is needed to develop a clearer picture of what makes the greatest esports player so great, and how newer players can be developed effectively.

Training for "Worst-Case" Scenarios in Sidestepping: Unifying Strength and Conditioning and Perception-Action Approaches

Sidesteps can impose high demands on the knee joint and lead to non-contact anterior cruciate ligament (ACL) injuries. Understanding how different constraints shape an athlete's movement strategy and the associated joint demands can help design training interventions to increase injury resilience. Motor capacities, such as muscular strength and power, act as boundaries for the safe execution of perceptual-motor skills and co-determine the emergence of unique movement strategies. Increasing single- and multi-joint strength enables a broader solution space for movement strategies and increases load tolerance. Manipulating task constraints during sidesteps can be used in the training process to systematically expose athletes to increasing demands (on the knee joint or any joint or structure) in preparation for "worst-case" scenarios. In particular, the type and timing of information available influence the preparation time, subsequently affecting the movement strategy and the associated magnitude of external knee joint loading (e.g., knee valgus moment). While an athlete's perceptual-cognitive skills contribute to the preparation time during in situ scenarios, attempts to further improve those skills with the aim of increasing athlete preparation time prior to "worst-case" scenarios are yet to demonstrate conclusive evidence of transfer to on-field situations. Therefore, in the current article, we reflect on the impact of different interacting constraints that influence the execution of sidesteps during in situ scenarios and impose high demands on the knee joint. Subsequently, we discuss how an integrated perspective, drawing on knowledge and perspectives from strength and conditioning and perception-action, may enhance an athlete's ability to withstand "worst-case" scenarios and adapt to perform varied movement executions when sidestepping.

Repeated conditionally automated driving on the road: How do drivers leave the loop over time?

The goal of this on the road driving study was to investigate how drivers adapt their behavior when driving with conditional vehicle automation (SAE L3) on different occasions. Specifically, we focused on changes in how fast drivers took over control from automation and how their gaze off the road changed over time. On each of three consecutive days, 21 participants drove for 50 min, in a conditionally automated vehicle (Wizard of Oz methodology), on a typical German commuting highway. Over these rides the take-over behavior and gaze behavior were analyzed. The data show that drivers' reactions to non-critical, system initiated, take-overs took about 5.62 s and did not change within individual rides, but on average became 0.72 s faster over the three rides. After these self-paced take-over requests a final urgent take-over request was issued at the end of the third ride. In this scenario participants took over rapidly with an average of 5.28 s. This urgent take-over time was not found to be different from the self-paced take-over requests in the same ride. Regarding gaze behavior, participants' overall longest glance off the road and the percentage of time looked off the road increased within each ride, but stayed stable over the three rides. Taken together, our results suggest that drivers regularly leave the loop by gazing off the road, but multiple exposures to take-over situations in automated driving allow drivers to come back into loop faster.

Perceptual-motor recalibration is intact in older adults

From an ecological perspective, perceptual-motor recalibration should be a robust and adaptable process, but there are suggestions that older adults may recalibrate slower. Therefore, this study investigated the age-related temporal effects in perceptual-motor recalibration after motor disturbances. In three experiments, we disturbed young and older adults' perception-action by fitting weights around their ankles and asking them to climb stairs or cross obstacles repeatedly. In Experiment 1, participants (n = 26) climbed stairs with different ankle weights. An innovative methodology was applied, identifying the timeline of recalibration as the point where a stable movement pattern emerged. Experiment 1 showed that older adults recalibrated slower than young adults in lighter (but not heavier) weight conditions. In Experiment 2, participants (n = 24) crossed obstacles with different ankle weights. Results showed that older adults recalibrated faster than young adults. Finally, in Experiment 3, participants (n = 24) crossed obstacles of unpredictable and varying heights with heavy ankle weights. Again, results showed that older adults recalibrated faster than young adults. Taken together these results show that although older adults had reduced muscle strength and flexibility, they recalibrated quickly, especially when the task was more challenging.

An embodied and ecological approach to skill acquisition in racecar driving

Racecar driving is a fast-paced sport that presents the driver-athlete with many perception-action coupling and decision-making challenges. One question that arises is how racecar drivers deal with the influx of perceptual information and manage to perform successfully in such high speeds and, as a result, very limited time to make decisions and act upon them. In this perspective paper, I suggest that the ecological approach is one theoretical framework that can help researchers understand how skill is acquired in racecar driving. I also suggest that an embodied perception of affordances can provide a good basis for research in the field. Specifically, it is an extended embodied cognition that includes not only the driver's mind and body, but the car itself. In a sense, the driver and the car are embodied into one unit and any perception of affordances should be based on this unit. This paper will also discuss the constraints during a race, the affordances the race driver must perceive and how they change over the course of a race, and how researchers can use a racecar driving paradigm to study human perception and action from an embodied and an ecological approach. Specifically, because the driver is seated, measuring EEG and eye movements is relatively simple and can provide additional information on drivers' visual perception of affordances, and their ability to act upon them.

Perceptual changes after learning of an arbitrary mapping between vision and hand movements

The present study examined the perceptual consequences of learning arbitrary mappings between visual stimuli and hand movements. Participants moved a small cursor with their unseen hand twice to a large visual target object and then judged either the relative distance of the hand movements (Exp.1), or the relative number of dots that appeared in the two consecutive target objects (Exp.2) using a two-alternative forced choice method. During a learning phase, the numbers of dots that appeared in the target object were correlated with the hand movement distance. In Exp.1, we observed that after the participants were trained to expect many dots with larger hand movements, they judged movements made to targets with many dots as being longer than the same movements made to targets with few dots. In Exp.2, another group of participants who received the same training judged the same number of dots as smaller when larger rather than smaller hand movements were executed. When many dots were paired with smaller hand movements during the learning phase of both experiments, no significant changes in the perception of movements and of visual stimuli were observed. These results suggest that changes in the perception of body states and of external objects can arise when certain body characteristics co-occur with certain characteristics of the environment. They also indicate that the (dis)integration of multimodal perceptual signals depends not only on the physical or statistical relation between these signals, but on which signal is currently attended.

The influence of age and age simulation on task-difficulty choices in motor tasks

    Having a realistic perception of one's motor abilities is important for successful aging. We used two different motor tasks, carrying a tray with cube-towers (study 1; n = 20 young adults; n = 20 older adults), and stepping over a crossbar (study 2; n = 23 young adults; n = 21 older adults), to investigate how physical risk influences task-difficulty choices. We also investigated the effect of wearing an age simulation suit on young adults. For the tray-carrying task, older adults were more risk-tolerant in their task-difficulty choices. When stepping over the crossbar, older adults left a larger "safety-buffer" than young adults. When wearing the age suit, young adults adopted a more careful strategy in the stepping task. We conclude that healthy older adults flexibly adjust their strategies to postural risks, and that young adults' strategy-choices can be influenced by experimentally inducing some of the sensory-motor constraints of old age.

Examining the effect of reduced action capabilities on defensive anticipation in a 1-vs-1 task

This study used small-sided games (SSGs) to induce fatigue and therefore, reduce the action capabilities of Varsity soccer players (n= 20). The aim was to examine the effect of compromised action capabilities on defensive movement response in a 1-vs-1 scenario. Action capabilities were assessed via countermovement jumps (CMJ), 5-m acceleration, 20-m sprint and a Change of Direction (COD) test. Defensive movement response was measured via a Soccer-Specific Anticipation Test (SSAT). Following SSGs, significant reductions were observed in jump (p=.04, d=.31), acceleration (p<.001, d=.98), and sprint (p<.001, d=.66) performance. Significantly, players tended to move earlier in the SSAT following SSGs (p=.049, d=.66). Furthermore, to examine the distinct effect of reductions in each action capability, players were categorised according to whether SSGs had a worthwhile change in CMJ, acceleration, sprint or COD performance. For each of the four measures, movements tended to be initiated earlier following SSGs, although pre-/post-SSGs differences were not significant (p =.08-.51), moderate to large effect sizes were shown (d=.56-.84). These findings intimate that compromised action capabilities influence the timing of the movement response of defensive players in 1-vs-1 situations.

The role of predictability of the magnitude of a perturbation in control of vertical posture when catching an object

The predictability of perturbation magnitude plays an important role in control of standing posture. The aim of the study was to examine anticipatory (APAs) and compensatory (CPAs) postural adjustments in response to catching objects of uncertain mass. Twenty adults caught the same object with either light or heavy weight placed in it. Electromyographic activity of eight trunk and leg muscles, displacements of the center of pressure, and angular displacement of the shoulder joint were recorded and analyzed during the APAs and CPAs intervals. When the subjects experienced repeated catching of the object with the same weight, they estimated the object mass beforehand and generated APAs more precisely. When the object mass changed unpredictably, they generated APAs based on the most recent catch and needed four to six trials to optimize APAs and CPAs. The muscle co-contraction was a primary pattern for catching the object of uncertain mass. The results of the study suggest that catching the object of uncertain mass is a challenging task that involves co-contraction of postural muscles to maintain balance.

Keeping the driver in the loop through semi-automated or manual lane changes in conditionally automated driving

In the current study we investigated if drivers of conditionally automated vehicles can be kept in the loop through lane change maneuvers. More specifically, we examined whether involving drivers in lane-changes during a conditionally automated ride can influence critical take-over behavior and keep drivers' gaze on the road. In a repeated measures driving simulator study (n = 85), drivers drove the same route three times, each trial containing four lane changes that were all either (1) automated, (2) semi-automated or (3) manual. Each ride ended with a critical take-over situation that could be solved by braking and/or steering. Critical take-over reactions were analyzed with a linear mixed model and parametric accelerated failure time survival analysis. As expected, semi-automated and manual lane changes throughout the ride led to 13.5% and 17.0% faster maximum deceleration compared to automated lane changes. Additionally, semi-automated and manual lane changes improved the quality of the take-over by significantly decreasing standard deviation of the steering wheel angle. Unexpectedly, drivers in the semi-automated condition were slowest to start the braking maneuver. This may have been caused by the drivers' confusion as to how the semi-automated system would react. Additionally, the percentage gaze off-the-road was significantly decreased by the semi-automated (6.0%) and manual (6.6%) lane changes. Taken together, the results suggest that semi-automated and manual transitions may be an alarm-free instrument which developers could use to help maintain drivers' perception-action loop and improve automated driving safety.

Exploring to learn and learning to explore

In respect to ecological psychology processes of attunement and calibration, this critical review focusses on how exploratory behaviors may contribute to skilled perception and action, with particular attention to sport. Based on the theoretical insights of Gibson (The senses considered as perceptual systems, Houghton Mifflin, Boston, 1966) and Reed (Encountering the world: Toward an ecological psychology, Oxford University Press, New York, 1996), exploratory and performatory actions have been differentiated in numerous experiments to study the perception of opportunities of action. The distinction between exploratory and performatory actions has informed the study of infant behavior in developmental psychology. In the current article, we highlight limitations with this distinction in the study of sports performers. We propose that a dynamic view of exploratory behavior would reveal how individuals develop exploratory activity that generates information about the fit between environmental properties and action capabilities. In this aim, practitioners should: (1) give learners the opportunity to safely develop exploratory behaviors even when they act outside their action boundary; and (2) guide learners to search for more reliable information to develop exploratory behaviors that would enhance the transfer of skills to various performance contexts.

Understanding a Player's Decision-Making Process in Team Sports: A Systematic Review of Empirical Evidence

Three perspectives were taken to explain decision-making within team sports (information processing, recognition primed decision-making, and ecological dynamics perspectives), resulting in conceptual tension and practical confusion. The aim of this paper was to interrogate empirical evidence to (1) understand the process of decision-making within team sports and (2) capture the characteristics of decision-making expertise in a team sport context. Nine electronic databases (SPORTDiscus, PsycINFO, PsycArticles, PsycTests, PubMed, SAGE journals online, Web of Knowledge, Academic Search Complete, and Web of Science) were searched until the final return in March 2021. Fifty-three articles satisfied the inclusion criteria, were analysed thematically, and synthesised using a narrative approach. Findings indicate that the relative absence or presence of mental representation within the decision-making process depends on factors, including complexity, typicality, time available, and contextual priors available in the game situation. We recommend that future research integrate concepts and methodologies prevalent within each perspective to better understand decision-making within team sports before providing implications for practitioners.

Learning and transfer of perceptual-motor skill: Relationship with gaze and behavioral exploration

Visual and haptic exploration were shown to be central modes of exploration in the development of locomotion. However, it is unclear how learning affects these modes of exploration in locomotor task such as climbing. The first aim of this study was to investigate the modifications of learners' exploratory activity during the acquisition of a perceptual-motor skill. The second aim was to determine to what extent the acquired perceptual-motor skill and the learners' exploratory activity were transferred to environments presenting novel properties. Seven participants attended 10 learning sessions on wall climbing. The effects of practice were assessed during pretest, posttest, and retention tests, each composed of four climbing routes: the route climbed during the learning sessions and three transfer routes. The transfer routes were designed by manipulating either the distance between handholds, the orientation of the handholds or the handholds shape. The results showed that the number of exploratory hand movements and fixations decreased with practice on the learning route. A visual entropy measure suggested that the gaze path in this route became more goal-directed on posttest, but some search was necessary on the retention test. The number of exploratory movements also decreased on the three transfer routes following practice, whereas the number of fixations was higher than on the learning route, suggesting that, with learning, participants relied more on exploration from a distance to adapt to the new properties of the transfer routes. Analyses of the individual performances and behaviors showed differences in the development of skilled exploratory activity.

Comparing driving behavior of humans and autonomous driving in a professional racing simulator

Motorsports have become an excellent playground for testing the limits of technology, machines, and human drivers. This paper presents a study that used a professional racing simulator to compare the behavior of human and autonomous drivers under an aggressive driving scenario. A professional simulator offers a close-to-real emulation of underlying physics and vehicle dynamics, as well as a wealth of clean telemetry data. In the first study, the participants' task was to achieve the fastest lap while keeping the car on the track. We grouped the resulting laps according to the performance (lap-time), defining driving behaviors at various performance levels. An extensive analysis of vehicle control features obtained from telemetry data was performed with the goal of predicting the driving performance and informing an autonomous system. In the second part of the study, a state-of-the-art reinforcement learning (RL) algorithm was trained to control the brake, throttle and steering of the simulated racing car. We investigated how the features used to predict driving performance in humans can be used in autonomous driving. Our study investigates human driving patterns with the goal of finding traces that could improve the performance of RL approaches. Conversely, they can also be applied to training (professional) drivers to improve their racing line.

The effects of testing environment, experimental design, and ankle loading on calibration to perturbed optic flow during locomotion

Calibration is the process by which the execution of actions becomes scaled to the (changing) relationship between environmental features and the actor's action capabilities. Though much research has investigated how individuals calibrate to perturbed optic flow, it remains unclear how different experimental factors contribute to the magnitude of calibration transfer. In the present study, we assessed how testing environment (Experiment 1), an adapted pretest-calibration-posttest design (Experiment 2), and bilateral ankle loading (Experiment 3) affected the magnitude of calibration to perturbed optic flow. We found that calibration transferred analogously to real-world and virtual environments. Although the magnitude of calibration transfer found here was greater than that reported by previous researchers, it was evident that calibration occurred rapidly and quickly plateaued, further supporting the claim that calibration is often incomplete despite continued calibration trials. We also saw an asymmetry in calibration magnitude, which may be due to a lack of appropriate perceptual-motor scaling prior to calibration. The implications of these findings for the assessment of distance perception and calibration in real-world and virtual environments are discussed.

Effects of Enriched Physical Activity Environments on Balance and Fall Prevention in Older Adults: A Scoping Review

The incidence of falling, due to aging, is related to both personal and environmental factors. There is a clear need to understand the nature of the major risk factors and design features of a safe and navigable living environment for potential fallers. The aim of this scoping review was to identify studies that have examined the effectiveness of environments, which promote physical activity and have an impact on falls prevention. Selected studies were identified and categorized into four main topics: built environment, environment modifications, enriched environments, and task constraints. The results of this analysis showed that there are a limited number of studies aiming to enhance dynamic postural stability and fall prevention through designing more functional environments. This scoping review study suggests that the design of interventions and the evaluation of an environment to support fall prevention are topics for future research.

How an Age Simulation Suit affects Motor and Cognitive Performance and Self-perception in Younger Adults

BACKGROUND/STUDY CONTEXT

We assessed the influence of wearing an Age Simulation Suit (GERT) on gross motor, fine motor and cognitive performance in healthy young adults.

METHODS

In a within-subjects design, we tested 20 young adults (M _age = 22.3 years) with and without the Age Simulation Suit. We assessed gross motor (Functional Fitness test) and fine motor (Purdue Pegboard test) functioning, cognitive performance (Digit Symbol Substitution test), and questionnaires on perceived physical state and mood. Gross and fine motor tests provided norms for large samples of older adults.

RESULTS

Wearing the Age Simulation Suit leads to significant performance reductions in all task dimensions, with large effect sizes. Depending on the subtest, participants' performances were reduced to the level of mid-50- to 85-years-olds for almost all tests of gross and fine motor performance. Mood and perceived physical state also declined while wearing the suit.

CONCLUSION

We argue that the GERT suit offers an attractive possibility to experimentally simulate the effects of aging-related sensory and motor losses and propose future studies with this paradigm, in the context of cognitive-motor dual-tasking or motor learning.

Getting Back Into the Loop: The Perceptual-Motor Determinants of Successful Transitions out of Automated Driving

OBJECTIVE

To present a structured, narrative review highlighting research into human perceptual-motor coordination that can be applied to automated vehicle (AV)-human transitions.

BACKGROUND

Manual control of vehicles is made possible by the coordination of perceptual-motor behaviors (gaze and steering actions), where active feedback loops enable drivers to respond rapidly to ever-changing environments. AVs will change the nature of driving to periods of monitoring followed by the human driver taking over manual control. The impact of this change is currently poorly understood.

METHOD

We outline an explanatory framework for understanding control transitions based on models of human steering control. This framework can be summarized as a perceptual-motor loop that requires (a) calibration and (b) gaze and steering coordination. A review of the current experimental literature on transitions is presented in the light of this framework.

RESULTS

The success of transitions are often measured using reaction times, however, the perceptual-motor mechanisms underpinning steering quality remain relatively unexplored.

CONCLUSION

Modeling the coordination of gaze and steering and the calibration of perceptual-motor control will be crucial to ensure safe and successful transitions out of automated driving.

APPLICATION

This conclusion poses a challenge for future research on AV-human transitions. Future studies need to provide an understanding of human behavior that will be sufficient to capture the essential characteristics of drivers reengaging control of their vehicle. The proposed framework can provide a guide for investigating specific components of human control of steering and potential routes to improving manual control recovery.