Manual Tracking Task Research Articles

Priority influences task selection decisions in multi-task management

The role of task priority on task selection in multi-task management is unclear based on prior work, leading to a common finding of ‘priority neglect’. However, properties such as urgency and conflict may influence whether operators weigh priority in their decision. We examined the role of instructed task prioritization, bolstered by more urgent and conflicting conditions, on how operators select among emergent, concurrent tasks when multitasking. Using the Multi-Attribute Task Battery (MATB) multitasking platform we tested both an auditory communications task and a manual tracking task as the priority tasks. Results showed that instructed priority significantly increased target task selection under the conflicting task conditions for both tasks. Urgency itself may modulate whether instructions to prioritize affect task selection choices when multitasking, and therefore counter to prior results instructions may yet be useful for helping operators select a higher priority task under conflict, a generalizable effect to be further explored.

The effect of different depth planes during a manual tracking task in three-dimensional virtual reality space

Unlike ballistic arm movements such as reaching, the contribution of depth information to the performance of manual tracking movements is unclear. Thus, to understand how the brain handles information, we investigated how a required movement along the depth axis would affect behavioral tracking performance, postulating that it would be affected by the amount of depth movement. We designed a visually guided planar tracking task that requires movement on three planes with different depths: a fronto-parallel plane called ROT (0), a sagittal plane called ROT (90), and a plane rotated by 45° with respect to the sagittal plane called ROT (45). Fifteen participants performed a circular manual tracking task under binocular and monocular visions in a three-dimensional (3D) virtual reality space. As a result, under binocular vision, ROT (90), which required the largest depth movement among the tasks, showed the greatest error in 3D. Similarly, the errors (deviation from the target path) on the depth axis revealed significant differences among the tasks. Under monocular vision, significant differences in errors were observed only on the lateral axis. Moreover, we observed that the errors in the lateral and depth axes were proportional to the required movement on these axes under binocular vision and confirmed that the required depth movement under binocular vision determined depth error independent of the other axes. This finding implies that the brain may independently process binocular vision information on each axis. Meanwhile, the required depth movement under monocular vision was independent of performance along the depth axis, indicating an intractable behavior. Our findings highlight the importance of handling depth movement, especially when a virtual reality situation, involving tracking tasks, is generated.

Age-related decline of online visuomotor adaptation: a combined effect of deteriorations of motor anticipation and execution.

The literature has established that the capability of visuomotor adaptation decreases with aging. However, the underlying mechanisms of this decline are yet to be fully understood. The current study addressed this issue by examining how aging affected visuomotor adaptation in a continuous manual tracking task with delayed visual feedback. To distinguish separate contributions of the declined capability of motor anticipation and deterioration of motor execution to this age-related decline, we recorded and analyzed participants' manual tracking performances and their eye movements during tracking. Twenty-nine older people and twenty-three young adults (control group) participated in this experiment. The results showed that the age-related decline of visuomotor adaptation was strongly linked to degraded performance in predictive pursuit eye movement, indicating that declined capability motor anticipation with aging had critical influences on the age-related decline of visuomotor adaptation. Additionally, deterioration of motor execution, measured by random error after controlling for the lag between target and cursor, was found to have an independent contribution to the decline of visuomotor adaptation. Taking these findings together, we see a picture that the age-related decline of visuomotor adaptation is a joint effect of the declined capability of motor anticipation and the deterioration of motor execution with aging.

Assistive Sensory Feedback for Trajectory Tracking in Augmented Reality

Abstract In recent years, Augmented Reality (AR) has been successfully applied in various fields to assist in the execution of manual tasks. However, there is still a lack of complete set of criteria for interface design for generating real-time interactive functions and effectively improving the task efficiency through AR. In this study, subjects performed two kinds of trajectory tracking tasks in AR, the simple trajectory and complex trajectory. Their task performance under five different sensory feedbacks, namely, central vision, peripheral vision, auditory sensation, tactile sensation and no feedback, were compared. The results show that in the trajectory tracking task in complex trajectories, the feedback information should not only provide prompts of error states, but also provide suggestions for correcting the actions to the subjects. In addition, compared with visual sensation and auditory sensation, the feedback information of tactile sensation has better adaptation. Furthermore, the subjects tend to rely on the real-time feedback of tactile sensation to complete difficult tasks. It was found that in the manual trajectory tracking task, determining whether the trajectory tracking task is within the acceptable trajectory range will be affected by the postures subjects use for the tasks, and will change the task performance. Therefore, it is suggested that when designing auxiliary functions, the limitations of the postures of the task should be considered. The experimental results and findings obtained in this study can provide a reference for the auxiliary interface design of manual tasks in AR.

Dual-task interference while receiving information on a head mounted display and manual tracking with and without auditory warnings

BackgroundDual-task interference is a concern when users attempt to use head mounted displays (HMD) while performing seated manual control tasks. Auditory warnings of information displayed on the HMD may or may not assist users while multi-tasking. ObjectiveIn this study, we investigated the dual-task interference of words, to be remembered later, presented on a HMD and motor control in a manual tracking task. The word presentations were warned or not warned with auditory signals and the impact of audio warnings were examined. MethodsParticipants were required to perform five tasks: (1) a compensatory tracking task performed alone, (2) a word memory task performed alone, (3) a tracking and word memory task, (4) a word memory task with words preceded by audial signals, and (5) a tracking and word memory task with words preceded by audial signals. In addition, in the dual-tasks, half of the word presentations were paired with directions changes in the tracking task to test for immediate perceptual interference. ResultsThere were significant dual task costs for both mean tracking error and later word recall. Additionally, participants took significantly longer to respond to motion changes paired with word presentations than motion changes not paired with word presentations. However, the impact of auditory warnings on tracking performance was nuanced. ConclusionEven with an in field of view transparent HMD momentary and sustained cognitive dual-task interference remains. Reaction times are affected most in the worst case scenario, when task critical events occur at the same time as a text message. ApplicationThe use of HMDs in time critical manual control tasks (such as operating machinery) should be limited. The use of audial warnings to alert operators to information displayed on an HMD requires further research; it may disrupt appropriate or natural task ordering.

Quantifying Motor Skills in Early-Stage Parkinson's Disease Using Human Controller Modeling

This paper investigates the potential of using a manual pursuit tracking task for quantifying loss of motor skills due to Parkinson's disease (PD), by applying human controller (HC) modeling techniques. With this approach, it is possible to obtain detailed quantitative data on motor performance in terms of control gain, response delay, stiffness and damping. Pursuit tracking data was collected from seven early-stage PD patients and a matched control group at the Erasmus MC in Rotterdam. Tracking performance was significantly worse in the PD group compared to the controls. Furthermore, the PD patients showed significantly lower control gains and degraded neuromuscular damping and bandwidth, which indicates that early-stage PD is associated with loss of quick and fast arm movements. While the PD patients showed less consistent and linear control behavior in the task, their data could still be modelled at high accuracy. Using HC models to quantify PD patients’ fine motor skill abilities may contribute to improved (early) detection of motor skill loss in PD, as well as detailed monitoring of symptom development and intervention effectiveness.

Degree and pattern of dual-task interference during walking vary with component tasks in people after stroke: a systematic review.

What are the degree and pattern of dual-task interference during walking in people after stroke? How do these vary with disease chronicity and different component tasks in people after stroke? How does dual-task interference differ between people after stroke and people without stroke? Systematic review with meta-analysis of studies reporting gait-related dual-task interference. People after stroke and people without stroke. Measures of walking and secondary (cognitive or manual) task performance under dual-task conditions relative to those under single-task conditions. Seventy-six studies (2,425 people after stroke and 492 people without stroke) were included. Manual and mental tracking tasks imposed the greatest dual-task interference on gait speed, although there was substantial uncertainty in these estimates. Among mental tracking tasks, the apparently least-complex task (serial 1 subtractions) induced the greatest dual-task interference (-0.17 m/s, 95% CI-0.24 to-0.10) on gait speed, although there was substantial uncertainty in these estimates. Mutual interference (decrement in both walking and secondary component task performances during dual-tasking) was the most common dual-task interference pattern. The results of the sensitivity analyses for studies involving people with chronic stroke were similar to the results of the primary analyses. The amount of dual-task interference from a mental tracking or manual task during walking was similar between people with or without stroke. The degree and pattern of dual-task interference vary with the choice of component tasks. When evaluating limitations to functional mobility during dual-tasking conditions and in planning interventions accordingly, clinicians should select dual-task assessments that correspond to the daily habits and physical demands of people after stroke. CRD42017059004.

De novo learning versus adaptation of continuous control in a manual tracking task.

How do people learn to perform tasks that require continuous adjustments of motor output, like riding a bicycle? People rely heavily on cognitive strategies when learning discrete movement tasks, but such time-consuming strategies are infeasible in continuous control tasks that demand rapid responses to ongoing sensory feedback. To understand how people can learn to perform such tasks without the benefit of cognitive strategies, we imposed a rotation/mirror reversal of visual feedback while participants performed a continuous tracking task. We analyzed behavior using a system identification approach, which revealed two qualitatively different components of learning: adaptation of a baseline controller and formation of a new, task-specific continuous controller. These components exhibited different signatures in the frequency domain and were differentially engaged under the rotation/mirror reversal. Our results demonstrate that people can rapidly build a new continuous controller de novo and can simultaneously deploy this process with adaptation of an existing controller.

Effects of Preview Time in Manual Tracking Tasks

In manual control tasks, preview of the target trajectory ahead is often limited by poor lighting, objects, or display edges. This paper investigates the effects of limited preview, or preview time, in manual tracking tasks with single- and double-integrator controlled element dynamics. A quasi-linear human controller model is used to predict the human behavior adaptations offline, by finding the model parameters that yield optimal performance at each preview time. These predictions are then verified by fitting the same model to measurements from a human-in-the-loop experiment, where subjects performed a tracking task with eight different preview time settings between 0 and 2 s. Results show that the tracking performance improves and the model's “look-ahead” time parameters increase with increasing preview time. Beyond a certain preview time, approximately 0.6 s and 1.15 s in single- and double-integrator tasks, respectively, additional preview evokes no further adaptations. The offline model predictions closely match the experimental results, which thereby promises to facilitate similar quantitative insights in other tasks with restricted preview.

Automation trust and attention allocation in multitasking workspace

Previous research suggests that operators with high workload can distrust and then poorly monitor automation, which has been generally inferred from automation dependence behaviors. To test automation monitoring more directly, the current study measured operators' visual attention allocation, workload, and trust toward imperfect automation in a dynamic multitasking environment. Participants concurrently performed a manual tracking task with two levels of difficulty and a system monitoring task assisted by an unreliable signaling system. Eye movement data indicate that operators allocate less visual attention to monitor automation when the tracking task is more difficult. Participants reported reduced levels of trust toward the signaling system when the tracking task demanded more focused visual attention. Analyses revealed that trust mediated the relationship between the load of the tracking task and attention allocation in Experiment 1, an effect that was not replicated in Experiment 2. Results imply a complex process underlying task load, visual attention allocation, and automation trust during multitasking. Automation designers should consider operators’ task load in multitasking workspaces to avoid reduced automation monitoring and distrust toward imperfect signaling systems.

Redundant-target processing is robust against changes to task load

Monitoring visual displays while performing other tasks is commonplace in many operational environments. Although dividing attention between tasks can impair monitoring accuracy and response times, it is unclear whether it also reduces processing efficiency for visual targets. Thus, the current three experiments examined the effects of dual-tasking on target processing in the visual periphery. A total of 120 undergraduate students performed a redundant-target task either by itself (Experiment 1a) or in conjunction with a manual tracking task (Experiments 1b–3). Target processing efficiency was assessed using measures of workload resilience. Processing of redundant targets in Experiments 1–2 was less efficient than predicted by a standard parallel race model, giving evidence for limited-capacity, parallel processing. However, when stimulus characteristics forced participants to process targets in serial (Experiment 3), processing efficiency became super-capacity. Across the three experiments, dual-tasking had no effect on target processing efficiency. Results suggest that a central task slows target detection in the display periphery, but does not change the efficiency with which multiple concurrent targets are processed.

Neural predictors of motor control and impact of visuo-proprioceptive information in youth.

For successful motor control, the central nervous system is required to combine information from the environment and the current body state, which is provided by vision and proprioception respectively. We investigated the relative contribution of visual and proprioceptive information to upper limb motor control and the extent to which structural brain measures predict this performance in youth (n = 40; age range 9-18 years). Participants performed a manual tracking task, adopting in-phase and anti-phase coordination modes. Results showed that, in contrast to older participants, younger participants performed the task with lower accuracy in general and poorer performance in anti-phase than in-phase modes. However, a proprioceptive advantage was found at all ages, that is, tracking accuracy was higher when proprioceptive information was available during both in- and anti-phase modes at all ages. The microstructural organization of interhemispheric connections between homologous dorsolateral prefrontal cortices, and the cortical thickness of the primary motor cortex were associated with sensory-specific accuracy of tracking performance. Overall, the findings suggest that manual tracking performance in youth does not only rely on brain regions involved in sensorimotor processing, but also on prefrontal regions involved in attention and working memory. Hum Brain Mapp 38:5628-5647, 2017. © 2017 Wiley Periodicals, Inc.

Climbing fibers predict movement kinematics and performance errors.

Requisite for understanding cerebellar function is a complete characterization of the signals provided by complex spike (CS) discharge of Purkinje cells, the output neurons of the cerebellar cortex. Numerous studies have provided insights into CS function, with the most predominant view being that they are evoked by error events. However, several reports suggest that CSs encode other aspects of movements and do not always respond to errors or unexpected perturbations. Here, we evaluated CS firing during a pseudo-random manual tracking task in the monkey (Macaca mulatta). This task provides extensive coverage of the work space and relative independence of movement parameters, delivering a robust data set to assess the signals that activate climbing fibers. Using reverse correlation, we determined feedforward and feedback CSs firing probability maps with position, velocity, and acceleration, as well as position error, a measure of tracking performance. The direction and magnitude of the CS modulation were quantified using linear regression analysis. The major findings are that CSs significantly encode all three kinematic parameters and position error, with acceleration modulation particularly common. The modulation is not related to "events," either for position error or kinematics. Instead, CSs are spatially tuned and provide a linear representation of each parameter evaluated. The CS modulation is largely predictive. Similar analyses show that the simple spike firing is modulated by the same parameters as the CSs. Therefore, CSs carry a broader array of signals than previously described and argue for climbing fiber input having a prominent role in online motor control.NEW & NOTEWORTHY This article demonstrates that complex spike (CS) discharge of cerebellar Purkinje cells encodes multiple parameters of movement, including motor errors and kinematics. The CS firing is not driven by error or kinematic events; instead it provides a linear representation of each parameter. In contrast with the view that CSs carry feedback signals, the CSs are predominantly predictive of upcoming position errors and kinematics. Therefore, climbing fibers carry multiple and predictive signals for online motor control.

Climbing Fibers Control Purkinje Cell Representations of Behavior.

A crucial issue in understanding cerebellar function is the interaction between simple spike (SS) and complex spike (CS) discharge, the two fundamentally different activity modalities of Purkinje cells. Although several hypotheses have provided insights into the interaction, none fully explains or is completely consistent with the spectrum of experimental observations. Here, we show that during a pseudo-random manual tracking task in the monkey (Macaca mulatta), climbing fiber discharge dynamically controls the information present in the SS firing, triggering robust and rapid changes in the SS encoding of motor signals in 67% of Purkinje cells. The changes in encoding, tightly coupled to CS occurrences, consist of either increases or decreases in the SS sensitivity to kinematics or position errors and are not due to differences in SS firing rates or variability. Nor are the changes in sensitivity due to CS rhythmicity. In addition, the CS-coupled changes in encoding are not evoked by changes in kinematics or position errors. Instead, CS discharge most often leads alterations in behavior. Increases in SS encoding of a kinematic parameter are associated with larger changes in that parameter than are decreases in SS encoding. Increases in SS encoding of position error are followed by and scale with decreases in error. The results suggest a novel function of CSs, in which climbing fiber input dynamically controls the state of Purkinje cell SS encoding in advance of changes in behavior.SIGNIFICANCE STATEMENT Purkinje cells, the sole output of the cerebellar cortex, manifest two fundamentally different activity modalities, complex spike (CS) discharge and simple spike (SS) firing. Elucidating cerebellar function will require an understanding of the interactions, both short- and long-term, between CS and SS firing. This study shows that CSs dynamically control the information encoded in a Purkinje cell's SS activity by rapidly increasing or decreasing the SS sensitivity to kinematics and/or performance errors independent of firing rate. In many cases, the CS-coupled shift in SS encoding leads a change in behavior. These novel findings on the interaction between CS and SS firing provide for a new hypothesis in which climbing fiber input adjusts the encoding of SS information in advance of a change in behavior.

Modeling Relationships among Workload, Trust, and Visual Scanning in an Automated Flight Task

The present study explored relationships among operators’ workload, subjective trust, and visual scanning patterns during their interaction with imperfect automation in a low-fidelity flight simulation task. Participants performed both a manual tracking task and a secondary system monitoring task (automated; FA- vs. miss-prone) under high and low load conditions manipulated by central task demand. The high load condition produced, 1) less frequent saccades toward system monitoring, 2) greater subjective workload, and 3) lower levels of subjective trust, compared to the low load condition. A mediation analysis revealed that subjective workload mediated the effect of load on visual scanning patterns whereas subjective trust did not. The results imply that, when the central task demands more attention, operators strategically reduce sampling rates of information from the system monitoring task assisted by imperfect automation depending on their subjective workload but not on subjective trust.

Change Detection for Measuring Attention Allocation

Attention allocation is an important component of situation awareness and is often assessed with eye tracking. A series of pilot studies were performed to examine a novel approach to evaluating attention in complex three dimensional environments that pose challenges to eye tracking methodologies. This novel approach involves integrating change detector objects into an existing interface to assess attention allocation within the interface. Three pilot studies examined the effectiveness of prototype change detector objects in conjunction with a primary manual tracking task. Change detection accuracy and response times were measured between change detectors located at systematically varying distances from the manual tracking task locus of attention. The results provide evidence for this approach to differentiate between interface regions and their associated attention allocation while completing a primary task. Future efforts will focus on examining the effectiveness of these change detectors in assessing attention allocation during a simulated nuclear process task using a microworld simulation environment.

Unchanging Capacity

Complex workspaces often require operators to divide attention between information within the visual periphery and a visual central task. For an air traffic controller, for example, monitoring complex displays while also watching for potential hazards is essential for avoiding aircraft collisions. In such environments, fast and accurate detection of peripheral events may be critical for safe performance. Presenting targets redundantly offers a potential way of speeding up target detection (Little, Eidels, Fific, & Wang, 2015; Townsend & Eidels, 2011). It remains unclear, however, whether redundant-target processing remains efficient with a concurrent central task. A series of experiments examined the effects of dual-tasking on peripheral redundant-target processing, either between- (Experiments 1a & 1b) or within-participants (Experiment 4). Furthermore, Experiments 2 and 3 manipulated target-distractor discriminability and distractor presence to examine the effects of target salience on dual-task processing efficiency. One hundred and one undergraduate students ( N =20 in each of Experiments 1a to 3; N = 21 in Experiment 4) performed a redundant-target task either by itself (Experiment 1a) or whilst performing a manual tracking task (Experiments 1b-4). The tracking task required participants to maneuver a joystick using both hands to align a cursor with a moving red target. The detection task required participants to press a joystick button bimanually whenever a target appeared at a location in the peripheral visual field. Experiments 1a, 1b, and Experiment 4 employed “T” as the target item and “L” as distractor items that appeared randomly rotated in 90° steps. In Experiment 2, target salience was increased by employing “X” as the target item and “O” for the distractor items. Experiment 3 tested peripheral target processing in the absence of distractors; hence, only the target item “T” was employed. Processing efficiency in the target-detection task was calculated using measures of resiliency (Little et al., 2015) or workload capacity (Townsend & Eidels, 2011). In all five experiments, processing of redundant targets was less efficient than predicted by a standard parallel race model (Raab, 1962; Townsend & Eidels, 2011). Surprisingly, processing efficiency differed negligibly between the single and dual-task conditions. Capacity may be protected from task-load effects due to separate information-processing resource pools within the central and peripheral visual fields (Wickens, 2002). Neither increasing the discriminability between targets and distractors, nor removing distractors entirely, had any effect on redundant-target processing efficiency. Results suggest target processing in the visual periphery is capacity-limited, but that processing efficiency is robust against changes to concurrent task load or target salience.

Influence of Focus of Attention Instructions on Performance of Manual Tracking Task at Different Speeds

PURPOSE: Instructions are an essential part of skill acquisition. Previous research (Wulf, 2007; Porter, 2010) has established that external focus of attention instruction (EFI) supersedes that of internal focus of attention instruction (IFI) on performance of a specific task. Tenants of dynamics systems theory however, dictate that a resulting performance occurs through the most optimal performance subsystems. Thus, as the constraints placed on a task shift so too does the performance of the system. Previously, Porter (2011) demonstrated that time on task (TT) performance on a novel rotary pursuit tracking task, at 15 rpms, was greatest with EFI compared to IFI. When the constraints on the task are altered, such as movement speed, it was hypothesized that self-organization of the subsystems would reduce the influence of instructions on performance outcomes. METHODS: 18 subjects (mean age=26.4; f=6; m=12) performed 3 x 30 s trials of a rotary tracking task in three experimental conditions at 40 rpm. The three conditions were: control (C), IFI and EFI. Conditions were counterbalanced to prevent an order effect with trials being performed on separate days. Data was analyzed using a 2 way repeated measures ANOVA 3 (instruction) x 3 (trial). RESULTS: Main effects for instruction (F2, 34= 7.19, p=0.002) and trial (F2, 34= 16.58, p=0.001) were observed between conditions. Post hoc analysis with Bonferroni adjustment indicated that both IFI and EFI demonstrated more TT than C, but were not different than each other (C= 18.21 SE= .88; IF = 20.24 SE = 1.08; EF = 21.32 SE = .92). CONCLUSIONS: Previous research would predict that EFI instruction would have more TT than IFI instruction. However, as evidenced by no differences between IFI & EFI conditions suggests performance is more greatly influenced by task constraints than focus of attention instructions. These findings suggest that movement practitioners should consider task constraints as a performance variable in conjunction with instructional considerations.

Subthreshold, noisy galvanic vestibular stimulation affects submovements in manual tracking tasks in Parkinson’s disease

s / Brain Stimulation 8 (2015) 395e411 401 through direct or indirect approach has shown promising results in relieving tinnitus in both human and animal subjects. Among the structures stimulated include the cochlear nucleus, auditory cortex, basal ganglion, and prefrontal cortex. However, there remains a large variability in therapeutic effects across different brain stimulation modalities. In order to achieve effective therapy, our lab has established animalmodels of brain stimulation to suppress tinnitus. We have been searching for optimal stimulation strategies and to delineate the underlyingmechanisms of brain-stimulation-induced tinnitus suppression. In this conference, I will present the latest development on tinnitus suppression through brain stimulation and discuss the underlying mechanisms and technological development.

Effects of old age and resource demand on double-step adaptation of saccadic eye movements.

It is still unknown whether adaptation of saccades--like that of arm movements-deteriorates in the presence of a concurrent resource--demanding task, and whether it is affected by old age. We therefore compared double-step adaptation of saccade directions in young and older persons exposed to the adaptation task only (groups CY & CO), to the adaptation task and a spatially adjacent manual tracking task (AY & AO) or to the adaptation task and a spatially distant manual tracking task (DY & DO). Adaptation was similar in all groups except DO: the latter group showed no consistent adaptation and no adequate aftereffects. Tracking improved little by practice in all groups except AY, where the improvement was substantial. Our data therefore provide no evidence for an impact of old age and resource demand on saccadic adaptation, possibly because the neural substrate partly differs from that for arm adaptation. The lack of adaptation in DO probably reflects the well-known shrinkage of the functional field of view in old age.