scholarly journals Infants prospectively control reaching based on the difficulty of future actions – To what extent can infants’ multiple step actions be explained by Fitts’ law?

2018 ◽  
Author(s):  
Janna M. Gottwald ◽  
Aurora De Bortoli Vizioli ◽  
Marcus Lindskog ◽  
Pär Nyström ◽  
Therese L. Ekberg ◽  
...  
Keyword(s):  
Motor Control ◽  
Motion Tracking ◽  
Tracking System ◽  
Action Planning ◽  
Task Demands ◽  
Fitts Law ◽  
Movement Unit ◽  
In The Beginning ◽  
Motion Tracking System ◽  
Goal Distance

Prospective motor control, a key element of action planning, is the ability to adjust one’s actions with respect to task demands and action goals in an anticipatory manner. The current study investigates whether 14-month-olds are able to prospectively control their reaching actions based on the difficulty of the subsequent action. We used a reach-to-place task, with difficulty of the placing action varied by goal size and goal distance. To target prospective motor control, we determined the kinematics of the prior reaching movements using a motion-tracking system. Peak velocity of the first movement unit of the reach served as indicator for prospective motor control. Both difficulty aspects (goal size and goal distance) affected prior reaching, suggesting that both these aspects of the subsequent action have an impact on the prior action. The smaller the goal size and the longer the distance to the goal, the slower infants were in the beginning of their reach towards the object. Additionally we modeled movement times of both reaching and placing actions using a formulation of Fitts’ law. The model was significant for placement and reaching movement times. These findings suggest that 14-month-olds are able to plan their future actions and prospectively control their related movements with respect to future task difficulties.

scholarly journals Measuring Prospective Motor Control in Action Development

2018 ◽  
Author(s):  
Janna M. Gottwald
Keyword(s):  
Motor Control ◽  
Motor Development ◽  
Motion Tracking ◽  
Peak Velocity ◽  
Action Planning ◽  
Human Movement ◽  
Fixed Time ◽  
Task Demands ◽  
Kinematic Measures ◽  
Movement Unit

This article critically reviews kinematic measures of prospective motor control. Prospective motor control, the ability to anticipatorily adjust movements with respect to task demands and action goals, is an important process involved in action planning. In manual object manipulation tasks, prospective motor control has been studied in various ways, mainly using motion tracking. For this matter, it is crucial to pinpoint the early part of the movement that purely reflects prospective (feed-forward) processes, but not feedback influences from the unfolding movement. One way of defining this period is to rely on a fixed time criterion; another is to base it flexibly on the inherent structure of each movement itself. Velocity—as one key characteristic of human movement—offers such a possibility and describes the structure of movements in a meaningful way. Here, I argue for the latter way of investigating prospective motor control by applying the measure of peak velocity of the first movement unit. I further discuss movement units and their significance in motor development of infants and contrast the introduced measure with other measures related to peak velocity and duration.

scholarly journals Measuring Prospective Motor Control in Action Development

2018 ◽  
Vol 6 (s1) ◽  
pp. S126-S137 ◽  
Author(s):  
Janna M. Gottwald
Keyword(s):  
Motor Control ◽  
Motor Development ◽  
Motion Tracking ◽  
Peak Velocity ◽  
Action Planning ◽  
Human Movement ◽  
Fixed Time ◽  
Task Demands ◽  
Kinematic Measures ◽  
Movement Unit

This article critically reviews kinematic measures of prospective motor control. Prospective motor control, the ability to anticipatorily adjust movements with respect to task demands and action goals, is an important process involved in action planning. In manual object manipulation tasks, prospective motor control has been studied in various ways, mainly using motion tracking. For this matter, it is crucial to pinpoint the early part of the movement that purely reflects prospective (feed-forward) processes, but not feedback influences from the unfolding movement. One way of defining this period is to rely on a fixed time criterion; another is to base it flexibly on the inherent structure of each movement itself. Velocity—as one key characteristic of human movement—offers such a possibility and describes the structure of movements in a meaningful way. Here, I argue for the latter way of investigating prospective motor control by applying the measure of peak velocity of the first movement unit. I further discuss movement units and their significance in motor development of infants and contrast the introduced measure with other measures related to peak velocity and duration.

scholarly journals Desktop lighting for comfortable use of a computer screen

Work ◽  
2021 ◽  
Vol 68 (s1) ◽  
pp. S209-S221
Author(s):  
Lu Han ◽  
Hechen Zhang ◽  
Zhongxia Xiang ◽  
Jinze Shang ◽  
Shabila Anjani ◽  
...  
Keyword(s):  
High Intensity ◽  
Motion Tracking ◽  
Tracking System ◽  
Computer User ◽  
Eye Tracker ◽  
Computer Screen ◽  
Task Load ◽  
Trunk Movements ◽  
Motion Tracking System ◽  
Nasa Task Load Index

BACKGROUND: The contrast between a bright computer screen and a dark ambient environment may influence comfort of the users, especially on their eyes. OBJECTIVE: The objective of this research is to identify the optimal desktop lighting for the comfortable use of the computer screen in a dark environment. METHODS: An experiment was designed where seven illumination setups were introduced for the users to perform their leisure tasks on a computer screen. Fifteen healthy subjects participated in the experiments. During each session, durations of the eye blinks, fixations and saccades of the user were recorded by an eye tracker. His/her neck and trunk movements were recorded by a motion tracking system as well. The comfort/discomfort questionnaire, localized postural discomfort questionnaire, NASA task load index and computer user questionnaire were used to record the overall comfort/discomfort, the local perceived physical discomfort, the cognitive workload, and general/eye health problems, respectively. RESULTS: Subjective and objective measurement results indicated that users felt more comfortable with high intensity warm lights using a computer screen. We also identified that the eye fixation durations, as well as the scores of two questions in the computer user questionnaire, have significant negative correlations with comfort. On the other side, the durations of blinks and the scores of three questions in the computer user questionnaire, were significantly correlated with discomfort. CONCLUSION: The warm (3000K) and high intensity (1500 lux) light reduced the visual and cognitive fatigue of the user and therefore improve the comfort of the user during the use of a computer screen.

scholarly journals Multi-sensor three-dimensional Monte Carlo localization for long-term aerial robot navigation

2017 ◽  
Vol 14 (5) ◽  
pp. 172988141773275 ◽  
Author(s):  
Francisco J Perez-Grau ◽  
Fernando Caballero ◽  
Antidio Viguria ◽  
Anibal Ollero
Keyword(s):  
Monte Carlo ◽  
Motion Tracking ◽  
Robot Navigation ◽  
Tracking System ◽  
Three Dimensional ◽  
Measurement Unit ◽  
Indoor Environments ◽  
Localization Algorithm ◽  
Monte Carlo Localization ◽  
Motion Tracking System

This article presents an enhanced version of the Monte Carlo localization algorithm, commonly used for robot navigation in indoor environments, which is suitable for aerial robots moving in a three-dimentional environment and makes use of a combination of measurements from an Red,Green,Blue-Depth (RGB-D) sensor, distances to several radio-tags placed in the environment, and an inertial measurement unit. The approach is demonstrated with an unmanned aerial vehicle flying for 10 min indoors and validated with a very precise motion tracking system. The approach has been implemented using the robot operating system framework and works smoothly on a regular i7 computer, leaving plenty of computational capacity for other navigation tasks such as motion planning or control.

Low-cost respiratory motion tracking system

2008 ◽  
Author(s):  
Mohammed Goryawala ◽  
Misael Del Valle ◽  
Jiali Wang ◽  
James Byrne ◽  
Juan Franquiz ◽  
...  
Keyword(s):  
Motion Tracking ◽  
Respiratory Motion ◽  
Tracking System ◽  
Low Cost ◽  
Motion Tracking System

scholarly journals Evaluation of the SteamVR Motion Tracking System with a Custom-Made Tracker

2021 ◽  
Vol 11 (14) ◽  
pp. 6390
Author(s):  
Marcin Maciejewski
Keyword(s):  
Motion Tracking ◽  
Tracking System ◽  
Training System ◽  
Random Errors ◽  
Operational Conditions ◽  
Custom Made ◽  
Systematic And Random Errors ◽  
Position And Orientation ◽  
Motion Tracking System ◽  
System Operating

The paper presents the research of the SteamVR tracker developed for a man-portable air-defence training system. The tests were carried out in laboratory conditions, with the tracker placed on the launcher model along with elements ensuring the faithful reproduction of operational conditions. During the measurements, the static tracker was moved and rotated in a working area. The range of translations and rotations corresponded to the typical requirements of a shooting simulator application. The results containing the registered position and orientation values were plotted on 3D charts which showed the tracker’s operation. Further analyses determined the values of the systematic and random errors for measurements of the SteamVR system operating with a custom-made tracker. The obtained results with random errors of 0.15 mm and 0.008° for position and orientation, respectively, proved the high precision of the measurements.

scholarly journals Infants in Control: Prospective Motor Control and Executive Functions in Action Development

2018 ◽  
Author(s):  
Janna M. Gottwald
Keyword(s):  
Motor Control ◽  
Cognitive Control ◽  
Executive Functions ◽  
Visual Information ◽  
Motion Tracking ◽  
Planning Process ◽  
Action Planning ◽  
Sources Of Information ◽  
Action Sequences ◽  
High Level

This thesis assesses the link between action and cognition early in development. Thus the notion of an embodied cognition is investigated by tying together two levels of action control in the context of reaching in infancy: prospective motor control and executive functions. The ability to plan our actions is the inevitable foundation of reaching our goals. Thus actions can be stratified on different levels of control. There is the relatively low level of prospective motor control and the comparatively high level of cognitive control. Prospective motor control is concerned with goal-directed actions on the level of single movements and movement combinations of our body and ensures purposeful, coordinated movements, such as reaching for a cup of coffee. Cognitive control, in the context of this thesis more precisely referred to as executive functions, deals with goal-directed actions on the level of whole actions and action combinations and facilitates directedness towards mid- and long-term goals, such as finishing a doctoral thesis. Whereas prospective motor control and executive functions are well studied in adulthood, the early development of both is not sufficiently understood.This thesis comprises three empirical motion-tracking studies that shed light on prospective motor control and executive functions in infancy. Study I investigated the prospective motor control of current actions by having 14-month-olds lift objects of varying weights. In doing so, multi-cue integration was addressed by comparing the use of visual and non-visual information to non-visual information only. Study II examined the prospective motor control of future actions in action sequences by investigating reach-to-place actions in 14-month-olds. Thus the extent to which Fitts’ law can explain movement duration in infancy was addressed. Study III lifted prospective motor control to a higher that is cognitive level, by investigating it relative to executive functions in 18-months-olds.Main results were that 14-month-olds are able to prospectively control their manual actions based on object weight. In this action planning process, infants use different sources of information. Beyond this ability to prospectively control their current action, 14-month-olds also take future actions into account and plan their actions based on the difficulty of the subsequentaction in action sequences. In 18-month-olds, prospective motor control in manual actions, such as reaching, is related to early executive functions, as demonstrated for behavioral prohibition and working memory. These findings are consistent with the idea that executive functions derive from prospective motor control. I suggest that executive functions could be grounded in the development of motor control. In other words, early executive functions should be seen as embodied.

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