Physical Motion Cues Research Articles

When "looking at nothing" imparts something: Retrospective gaze cues flexibly direct prioritization in visual working memory.

Previous research has shown that retrospective gaze cues direct attention to internally maintained representations in visual working memory (vWM). Here, we aimed to differentiate the dual nature of gaze and accordingly proposed two hypotheses regarding the gaze-induced prioritization in vWM. The directional cueing hypothesis claims a constant attentional shifting to the gazed-at direction. By contrast, the referential cueing hypothesis proposes that gaze cues selectively orient attention toward their referents. To test these hypotheses, we employed an adapted change-detection task wherein gaze cues were presented during the retention interval. Critically, the cue character was positioned between two barriers, which could be either opaque (the blocked condition) or transparent (the unblocked condition). Polygons previously presented at the gazed-at (vs. gazed-away) location were better memorized, but not when the visual perspective of the character was obstructed (i.e., the blocked condition, Experiment 1). Subsequent experiments demonstrated that physical motion cues (Experiment 2) and inverted face cues (Experiment 3), which disrupted the extraction of referential signals, were immune to barrier settings. In Experiment 4, we generalize this selective cueing effect to faces with fearful expressions. These consistent findings support the referential cueing hypothesis and emphasize the distinctiveness of social attention. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Stimulus Onset Asynchrony Affects Weighting-related Event-related Spectral Power in Self-motion Perception.

Self-motion perception relies primarily on the integration of the visual, vestibular, proprioceptive, and somatosensory systems. There is a gap in understanding how a temporal lag between visual and vestibular motion cues affects visual-vestibular weighting during self-motion perception. The beta band is an index of visual-vestibular weighting, in that robust beta event-related synchronization (ERS) is associated with visual weighting bias, and robust beta event-related desynchronization is associated with vestibular weighting bias. The present study examined modulation of event-related spectral power during a heading judgment task in which participants attended to either visual (optic flow) or physical (inertial cues stimulating the vestibular, proprioceptive and somatosensory systems) motion cues from a motion simulator mounted on a MOOG Stewart Platform. The temporal lag between the onset of visual and physical motion cues was manipulated to produce three lag conditions: simultaneous onset, visual before physical motion onset, and physical before visual motion onset. There were two main findings. First, we demonstrated that when the attended motion cue was presented before an ignored cue, the power of beta associated with the attended modality was greater than when visual-vestibular cues were presented simultaneously or when the ignored cue was presented first. This was the case for beta ERS when the visual-motion cue was attended to, and beta event-related desynchronization when the physical-motion cue was attended to. Second, we tested whether the power of feature-binding gamma ERS (demonstrated in audiovisual and visual-tactile integration studies) increased when the visual-vestibular cues were presented simultaneously versus with temporal asynchrony. We did not observe an increase in gamma ERS when cues were presented simultaneously, suggesting that electrophysiological markers of visual-vestibular binding differ from markers of audiovisual and visual-tactile integration. All event-related spectral power reported in this study were generated from dipoles projecting from the left and right motor areas, based on the results of Measure Projection Analysis.

The Impact of Physical Motion Cues on Driver Braking Performance: A Clinical Study Using Driving Simulator and Eye Tracker.

Driving simulators are increasingly being incorporated by driving schools into a training process for a variety of vehicles. The motion platform is a major component integrated into simulators to enhance the sense of presence and fidelity of the driving simulator. However, less effort has been devoted to assessing the motion cues feedback on trainee performance in simulators. To address this gap, we thoroughly study the impact of motion cues on braking at a target point as an elementary behavior that reflects the overall driver's performance. In this paper, we use an eye-tracking device to evaluate driver behavior in addition to evaluating data from a driving simulator and considering participants' feedback. Furthermore, we compare the effect of different motion levels ("No motion", "Mild motion", and "Full motion") in two road scenarios: with and without the pre-braking warning signs with the speed feedback given by the speedometer. The results showed that a full level of motion cues had a positive effect on braking smoothness and gaze fixation on the track. In particular, the presence of full motion cues helped the participants to gradually decelerate from 5 to 0 ms-1 in the last 240 m before the stop line in both scenarios, without and with warning signs, compared to the hardest braking from 25 to 0 ms-1 produced under the no motion cues conditions. Moreover, the results showed that a combination of the mild motion conditions and warning signs led to an underestimation of the actual speed and a greater fixation of the gaze on the speedometer. Questionnaire data revealed that 95% of the participants did not suffer from motion sickness symptoms, yet participants' preferences did not indicate that they were aware of the impact of simulator conditions on their driving behavior.

The New Era of Virtual Reality Locomotion: A Systematic Literature Review of Techniques and a Proposed Typology

The latest technical and interaction advancements that took place in the Virtual Reality (VR) field have marked a new era, not only for VR, but also for VR locomotion. Although the latest advancements in VR locomotion have raised the interest of both researchers and users in analyzing and experiencing current VR locomotion techniques, the field of research on VR locomotion, in its new era, is still uncharted. In this work, VR locomotion is explored through a systematic literature review investigating empirical studies of VR locomotion techniques from 2014–2017. The review analyzes the VR locomotion techniques that have been studied, their interaction-related characteristics and the research topics that were addressed in these studies. Thirty-six articles were identified as relevant to the literature review, and the analysis of the articles resulted in 73 instances of 11 VR locomotion techniques, such as real-walking, walking-in-place, point and teleport, joystick-based locomotion, and more. Results showed that since the VR revival, the focus of VR locomotion research has been on VR technology and various technological aspects, overshadowing the investigation of user experience. From an interaction perspective, the majority of the utilized and studied VR locomotion techniques were found to be based on physical interaction, exploiting physical motion cues for navigation in VR environments. A significant contribution of the literature review lies in the proposed typology for VR locomotion, introducing four distinct VR locomotion types: motion-based, room scale-based, controller-based and teleportation-based locomotion.

Identification of Multimodal Pilot Control Behavior in Real Flight

Flight simulators are widely used for research and training of pilots. However, in skill-based control tasks, pilots behave differently in the simulator compared to real flight, due to limited visual and physical motion cues. This warrants a method that quantifies simulator fidelity by the differences between pilot control behavior in real flight and in the simulator. This paper presents the results of in-flight experiments to determine multimodal pilot control behavior in real flight, the baseline in determining simulator fidelity. The experiment is performed in a Cessna Citation II laboratory aircraft with a custom-built fly-by-wire system. To estimate pilots' visual and vestibular responses, two forcing functions need to be inserted into the control loop at different locations. The fly-by-wire system was used to physically disturb the aircraft with a disturbance forcing function, while pilots had to track a target forcing function on a display in the cockpit. Both a multisine and a ramp target signal were tested in roll and pitch control tasks, resulting in four experimental conditions. The results show that multimodal pilot control behavior can indeed be identified in real flight using the current fly-by-wire system setup. For two pilots, pilot model parameters could be estimated with high accuracy for all conditions. For some conditions of the two remaining pilots, however, no accurate parameter estimates could be found, as their control activity did not allow for a stable global optimum of the parameter estimation problem.

Self versus Environment Motion in Postural Control

To stabilize our position in space we use visual information as well as non-visual physical motion cues. However, visual cues can be ambiguous: visually perceived motion may be caused by self-movement, movement of the environment, or both. The nervous system must combine the ambiguous visual cues with noisy physical motion cues to resolve this ambiguity and control our body posture. Here we have developed a Bayesian model that formalizes how the nervous system could solve this problem. In this model, the nervous system combines the sensory cues to estimate the movement of the body. We analytically demonstrate that, as long as visual stimulation is fast in comparison to the uncertainty in our perception of body movement, the optimal strategy is to weight visually perceived movement velocities proportional to a power law. We find that this model accounts for the nonlinear influence of experimentally induced visual motion on human postural behavior both in our data and in previously published results.

Optimization of Human Perception Modeling Using Interval Analysis

Estimating multi-modal pilot model parameters from experiment or simulation data requires solving a global nonlinear optimization problem with many local minimums. Using the traditional parameter estimation techniques, finding the global optimum is dependent on the initial parameter estimate. In this paper the parameter optimization is performed by using the theory of interval analysis, which deals with intervals of numbers instead of crisp numbers. Interval analysis has been shown to be an excellent tool for global nonlinear optimization and it can guarantee that the global minimum of the cost function is found. The interval optimization method is applied to data from an experiment investigating the role of optic flow and the influence of physical motion cues during control of self-motion. A comparison between gradient based and interval optimization shows that the interval method can find the global minimum of the cost function, resulting in the optimal set of model parameters, while the gradient-based method often converges to a local minimum.

Effects of Peripheral Visual and PhysicalMotion Cues in Roll-Axis Tracking Tasks

In this paper, the effects of peripheral visual and physical motion cues on manual control of second-order roll dynamics are investigated. In particular, the differences between the use of these cues in compensatory target-following and disturbance-rejection tasks are considered. Tracking performance, control activity, and measures of control behavior are determined from recent measurements and compared with results from an earlier experiment. Most previously reported effects of peripheral visual and physical motion cues in target following and disturbance rejection are confirmed. A comparison of tasks with varying levels of difficulty is found to reveal reduced effectiveness of peripheral visual and physical motion cues in the less difficult target-following tasks only. Observed differences in measured control behavior for target following and disturbance rejection are related to effective strategies for reducing tracking errors introduced by the forcing-function signals in both tasks.

Spatial updating in virtual reality: the sufficiency of visual information

Robust and effortless spatial orientation critically relies on "automatic and obligatory spatial updating", a largely automatized and reflex-like process that transforms our mental egocentric representation of the immediate surroundings during ego-motions. A rapid pointing paradigm was used to assess automatic/obligatory spatial updating after visually displayed upright rotations with or without concomitant physical rotations using a motion platform. Visual stimuli displaying a natural, subject-known scene proved sufficient for enabling automatic and obligatory spatial updating, irrespective of concurrent physical motions. This challenges the prevailing notion that visual cues alone are insufficient for enabling such spatial updating of rotations, and that vestibular/proprioceptive cues are both required and sufficient. Displaying optic flow devoid of landmarks during the motion and pointing phase was insufficient for enabling automatic spatial updating, but could not be entirely ignored either. Interestingly, additional physical motion cues hardly improved performance, and were insufficient for affording automatic spatial updating. The results are discussed in the context of the mental transformation hypothesis and the sensorimotor interference hypothesis, which associates difficulties in imagined perspective switches to interference between the sensorimotor and cognitive (to-be-imagined) perspective.

Driver steering reaction time to abrupt-onset crosswinds, as measured in a moving-base driving simulator.

A moving-base driving simulator was used in three experiments involving driver reaction time (RT) to simulated crosswind disturbances. Analyses were conducted on driver steering reaction time (RT) to the disturbances. Experiment 1 revealed that RT was significantly shorter when physical-motion cues were present. A second variable, vehicle yaw rate rise time, showed no effect. In Experiment 2, design parameters influencing aerodynamic behavior of a vehicle were adjusted. RT increased as the vehicle center of pressure (point of crosslvind application) moved rearward (rom the (ront axle. However, rearward movement of the center of pressure also produced less disturbance of the vehicle itself Changes in understeer and steering sensitivity yielded no significant effect. In Experiment 3, both uninitiated drivers and drivers with time on task were examined. Neither the first exposure to a step gust nor driving time up to 150 mirl caused significant changes in RT when perfurmance was compared with that of practiced, fresh drivers. Interexperiment comparisons using crosswind amplitude and shape as independent variables demonstrated that the amplitude and rise time of the crosswinds were critical determinants of steering RT.

Comparison of Computer-Generated and Simulated Motion Picture Displays in a Driving Simulation

An automotive driving simulator with a computer-generated display system, three axes of physical motion (roll, yaw, and lateral translation), sound, and vibration cues was used to investigate and compare human psychomotor response and vehicle response to different types of displays and motion cues. Subjects drove the simulator under four levels of displays; three being simulated preprogrammed motion picture displays (MPDS), one being the standard computer-generated display (CGDS). Motion and no-motion conditions were instituted at each display level. Each data run included lane-keeping and lane-changing tasks for various simulated highway conditions. During lane changes under MPDS conditions, both preprogrammed and nonpreprogrammed simulator conditions were examined. Seven dependent variables were used to measure performance. Results of the experiment show that one level of the simulated preprogrammed MPDS produced performance similar to that of a CGDS in all seven measures, whereas the other levels differed significantly. This suggests that using a properly instrumented preprogrammed MPDS will not compromise experimental results for certain research and educational experiments, and that in many cases an economical simulation using an MPDS would be adequate.

The Influence of Motion and Audio Cues on Driver Performance in an Automobile Simulator

A highway driving simulator with a computer-generated visual display, physical motion cues of roll, yaw, and lateral translation, and velocity-dependent sound/vibration cues was used to investigate the influence of these cues on driver performance. Forty-eight student subjects were randomly allocated to six experimental groups. Each group of eight subjects experienced a unique combination of the motion and audio cues. The control group received a full simulation condition while each of the remaining five groups performed with certain combinations of motion and sound deleted. Each driver generated nine minutes of continuous data from which five performance measures were derived. Results indicate that the performance measures of yaw, lateral, and velocity deviation are significantly affected by the deletion of cues. In support of the hypothesis that driver performance is augmented by the addition of motion cues, statistically significant negative correlations were obtained between the number of motion cues present and the measures of yaw and lateral deviation. With respect to motion and audio cues, recommendations are made regarding simulator design criteria.

Aircraft Simulator Motion and the Order of Merit of Flight Attitude and Steering Guidance Displays

Twenty-four nonpilot, volunteer subjects were tested on three flight tasks while flying four basic aircraft attitude presentations (moving horizon, moving airplane, frequency-separated, and kinalog) in a light twin-engine aircraft simulator providing three types of motion cues (no motion, standard GAT-2 motion, and washout motion). The flight tasks involved conflicting visual and vestibular cues and included disturbed attitude tracking, command flight path tracking in both pursuit and compensatory modes, and a series of recovery trials from discrete unknown attitudes. To provide a basis for comparison, the present simulator study closely replicated the procedures used in the Roscoe and Williges (1975) flight experiment. The frequency-separated display yielded performances at least equivalent and in some cases superior to those obtained with the conventional moving horizon display. Either type of simulator motion resulted in better disturbed attitude tracking performance than no motion, and washout motion provided stereotypic control responses in recovery from unknown attitudes most closely corresponding to those obtained in flight. It was concluded that care must be used in generalizing simulator results to flight performance when no physical motion cues or inappropriate ones are present in the simulator.