Prediction of Head Movement Time Using Fitts’ Law

1989 ◽  
Vol 31 (6) ◽  
pp. 703-713 ◽  
Author(s):  
Robert O. Andres ◽  
Kenny J. Hartung
Keyword(s):  
Head Movement ◽  
Movement Time ◽  
Body Movement ◽  
Prediction Equation ◽  
Head Movements ◽  
Valuable Insight ◽  
College Age ◽  
Fitts Law ◽  
Upper And Lower Extremities ◽  
Physically Challenged

Fitts’ movement time prediction equation has been applied and manipulated in analyzing movements of the upper and lower extremities in healthy populations. One common job modification for physically challenged workers is the use of a head or chin stick to depress keys on a keyboard, making use of head movements when movements of the extremities are problematic. The purpose of this research was to assess the applicability of Fitts’ law for the prediction of head movement time. Movement was restricted in healthy subjects by limiting body movement below the neck. Subjects were asked to reciprocally move a chin stylus between targets of various widths and separations. The present study found that Fitts’ law was a robust predictor of head movement time in healthy, college-age males using a chin stylus. Although small within-subjects trends were noted, there were no significant learning effects from Session 1 to Session 2. The mean information-processing rate for the experimental head movement was 7 bits/s, much less than that reported for extremities. These results can provide rehabilitation and industrial engineers valuable insight into the added demands of jobs designed to use repetitive head movements.

scholarly journals Development of a Drawing Application for Communication Support during Endoscopic Surgery and its Evaluation Using Steering Law

2021 ◽  
Vol 11 (10) ◽  
pp. 4505
Author(s):  
Takafumi Asao ◽  
Takeru Kobayashi ◽  
Kentaro Kotani ◽  
Satoshi Suzuki ◽  
Kazutaka Obama ◽  
...  
Keyword(s):  
Endoscopic Surgery ◽  
Head Movement ◽  
Movement Time ◽  
Collaborative Work ◽  
Subjective Evaluation ◽  
Line Drawing ◽  
Head Movements ◽  
Coefficient Of Determination ◽  
Communication Support ◽  
Steering Law

The purpose of this study is to construct a hands-free endoscopic surgical communication support system that can draw lines in space corresponding to head movements using AR technology and evaluate the applicability of the drawing motion by the head movement to the steering law, one of the HCI models, for the potential use during endoscopic surgery. In the experiment, the participants manipulated the cursor by using head movements through the pathway and movement time (MT); the number of errors and subjective evaluation of the difficulty of the task was obtained. The results showed that the head-movement-based line drawing manipulation was significantly affected by the tracking direction and by the task difficulty, shown as the Index of Difficulty (ID). There was high linearity between ID and MT, with a coefficient of determination R² of 0.9991. The Index of Performance was higher in the horizontal and vertical directions compared to diagonal directions. Although the weight and biocompatibility of the AR glasses must be overcome to make the current prototype a viable tool for supporting communication in the operating room environment, the prototype has the potential to promote the development of a computer-supported collaborative work environment for endoscopic surgery purposes.

Role of pinnae and head movements in localizing pure tones 1The authors would like to thank Mr. Remi Humbert for implementing the experiment in Turbo Pascal and for his further assistance.

1999 ◽  
Vol 58 (3) ◽  
pp. 170-179 ◽  
Author(s):  
Barbara S. Muller ◽  
Pierre Bovet
Keyword(s):  
Sound Source ◽  
Head Movement ◽  
Movement Analysis ◽  
Head Movements ◽  
Sound Sources ◽  
Localization Accuracy ◽  
Sound Effects ◽  
Posterior Quadrant ◽  
Localization Performance ◽  
Pure Tones

Twelve blindfolded subjects localized two different pure tones, randomly played by eight sound sources in the horizontal plane. Either subjects could get information supplied by their pinnae (external ear) and their head movements or not. We found that pinnae, as well as head movements, had a marked influence on auditory localization performance with this type of sound. Effects of pinnae and head movements seemed to be additive; the absence of one or the other factor provoked the same loss of localization accuracy and even much the same error pattern. Head movement analysis showed that subjects turn their face towards the emitting sound source, except for sources exactly in the front or exactly in the rear, which are identified by turning the head to both sides. The head movement amplitude increased smoothly as the sound source moved from the anterior to the posterior quadrant.

scholarly journals Neural Basis of Visually Guided Head Movements Studied With fMRI

2003 ◽  
Vol 89 (5) ◽  
pp. 2516-2527 ◽  
Author(s):  
Laurent Petit ◽  
Michael S. Beauchamp
Keyword(s):  
Eye Movements ◽  
Head Movement ◽  
Brain Activity ◽  
Posterior Part ◽  
Vestibular Stimulation ◽  
Head Movements ◽  
Oculomotor Control ◽  
Imaging Studies ◽  
Neural Basis ◽  
Temporoparietal Junction

We used event-related fMRI to measure brain activity while subjects performed saccadic eye, head, and gaze movements to visually presented targets. Two distinct patterns of response were observed. One set of areas was equally active during eye, head, and gaze movements and consisted of the superior and inferior subdivisions of the frontal eye fields, the supplementary eye field, the intraparietal sulcus, the precuneus, area MT in the lateral occipital sulcus and subcortically in basal ganglia, thalamus, and the superior colliculus. These areas have been previously observed in functional imaging studies of human eye movements, suggesting that a common set of brain areas subserves both oculomotor and head movement control in humans, consistent with data from single-unit recording and microstimulation studies in nonhuman primates that have described overlapping eye- and head-movement representations in oculomotor control areas. A second set of areas was active during head and gaze movements but not during eye movements. This set of areas included the posterior part of the planum temporale and the cortex at the temporoparietal junction, known as the parieto-insular vestibular cortex (PIVC). Activity in PIVC has been observed during imaging studies of invasive vestibular stimulation, and we confirm its role in processing the vestibular cues accompanying natural head movements. Our findings demonstrate that fMRI can be used to study the neural basis of head movements and show that areas that control eye movements also control head movements. In addition, we provide the first evidence for brain activity associated with vestibular input produced by natural head movements as opposed to invasive caloric or galvanic vestibular stimulation.

Sickness induced by head movements after different centrifugal Gx-loads and durations

2008 ◽  
Vol 17 (5-6) ◽  
pp. 323-332
Author(s):  
Suzanne A.E. Nooij ◽  
Jelte E. Bos
Keyword(s):  
Short Duration ◽  
Time Constant ◽  
Head Movement ◽  
Head Movements ◽  
Symptom Intensity ◽  
Space Adaptation Syndrome ◽  
Space Adaptation ◽  
Exponential Fit

It has been found that sustained centrifugation on Earth may evoke sickness symptoms that are similar to those of the Space Adaptation Syndrome (SAS). As in SAS, incidence of this 'Sickness Induced by Centrifugation' (SIC) is about 50% and the symptoms are particularly evoked by head movements. By systematically varying the G-load and duration of centrifugation, the current study investigated the characteristics of the gravitational stimulus that is required for SIC to occur. Subjects were exposed to centrifugation at 2 and 3Gx, for a duration of 45 and 90 minutes. A standardized head movement protocol was used to evoke SIC after centrifugation. The results show that in six out of 12 subjects (50%) no serious symptoms were elicited. In the remaining subjects, the effects of the 3G runs exceeded those of the 2G runs, and within each G-level symptom intensity was higher for the 90 min than for the 45 min exposure. An exponential fit on this data showed that the time constant of adaptation to the gravitational stimulus was about 60 minutes. This suggests that short duration exposures (i.e. < 60 min) are not likely to induce serious SIC.

Active head movements facilitate compensation for effects of prism displacement on dynamic gait12

2006 ◽  
Vol 16 (1-2) ◽  
pp. 29-33
Author(s):  
Kim R. Gottshall ◽  
Michael E. Hoffer ◽  
Helen S. Cohen ◽  
Robert J. Moore
Keyword(s):  
Head Movement ◽  
Sensory Modality ◽  
Normal Subjects ◽  
The Body ◽  
Head Movements ◽  
Head Motion ◽  
Control Group ◽  
Entire Body ◽  
Group 3 ◽  
Group 2

Study design: Four groups, between-subjects study. Objectives: To investigate the effects of exercise on adaptation of normal subjects who had been artificially spatially disoriented. Background: Many patients referred for rehabilitation experience sensory changes, due to age or disease processes, and these changes affect motor skill. The best way to train patients to adapt to these changes and to improve their sensorimotor skills is unclear. Using normal subjects, we tested the hypothesis that active, planned head movement is needed to adapt to modified visual input. Methods and measures: Eighty male and female subjects who had normal balance on computerized dynamic posturography (CDP) and the dynamic gait index (DGI), were randomly assigned to four groups. All groups donned diagonally shift lenses and were again assessed with CDP and DGI. The four groups were then treated for 20 min. Group 1 (control group) viewed a video, Group 2 performed exercise that involved translating the entire body through space, but without separate, volitional head movement, Group 3 performed exercises which all incorporated volitional, planned head rotations, and Group 4 performed exercises that involved translating the body (as in Group 2) and incorporated volitional, planned head motion (as in Group 3). All subjects were post-tested with CDP and DGI, lenses were removed, and subjects were retested again with CDP and DGI. Results: The groups did not differ significantly on CDP scores but Groups 3 and 4 had significantly better DGI scores than Groups 1 and 2. Conclusions: Active head movement that is specifically planned as part of the exercise is more effective than passive attention or head movements that are not consciously planned, for adapting to sensorimotor change when it incorporates active use of the changed sensory modality, in this case head motion.

Movement Time to an Array of Controls

1993 ◽  
Vol 37 (9) ◽  
pp. 625-629 ◽  
Author(s):  
Errol R. Hoffmann
Keyword(s):  
Mathematical Model ◽  
Theoretical Result ◽  
Movement Time ◽  
Element Model ◽  
Optimum Control ◽  
Fitts Law ◽  
Model Based ◽  
Array Density

Two tasks in which subjects aim at an array of devices were considered: moving to one knob within an array and moving the finger on a numeric keypad. It was shown by a mathematical model based on Fitts' law, that when the array density is specified for the array of knobs or keys, there is an optimum control size for minimum movement time. The theoretical result was obtained by considering a two-element model of the movement, the first being a reach to the general location of the control and the second describing the insertion of the fingers into the space between adjacent controls. As the first element has a movement time that decreases with increase of control size and the second a time increasing with control size, there is an optimum control size where the movement time is a minimum.

Rapid horizontal gaze movement in the monkey

1995 ◽  
Vol 73 (4) ◽  
pp. 1632-1652 ◽  
Author(s):  
J. O. Phillips ◽  
L. Ling ◽  
A. F. Fuchs ◽  
C. Siebold ◽  
J. J. Plorde
Keyword(s):  
Eye Movement ◽  
Head Movement ◽  
Vertical Axis ◽  
Head Position ◽  
Head Movements ◽  
Gaze Shifts ◽  
Gaze Shift ◽  
The Gaze ◽  
Small Correction ◽  
Horizontal Gaze

1. We studied horizontal eye and head movements in three monkeys that were trained to direct their gaze (eye position in space) toward jumping targets while their heads were both fixed and free to rotate about a vertical axis. We considered all gaze movements that traveled > or = 80% of the distance to the new visual target. 2. The relative contributions and metrics of eye and head movements to the gaze shift varied considerably from animal to animal and even within animals. Head movements could be initiated early or late and could be large or small. The eye movements of some monkeys showed a consistent decrease in velocity as the head accelerated, whereas others did not. Although all gaze shifts were hypometric, they were more hypometric in some monkeys than in others. Nevertheless, certain features of the gaze shift were identifiable in all monkeys. To identify those we analyzed gaze, eye in head position, and head position, and their velocities at three points in time during the gaze shift: 1) when the eye had completed its initial rotation toward the target, 2) when the initial gaze shift had landed, and 3) when the head movement was finished. 3. For small gaze shifts (< 20 degrees) the initial gaze movement consisted entirely of an eye movement because the head did not move. As gaze shifts became larger, the eye movement contribution saturated at approximately 30 degrees and the head movement contributed increasingly to the initial gaze movement. For the largest gaze shifts, the eye usually began counterrolling or remained stable in the orbit before gaze landed. During the interval between eye and gaze end, the head alone carried gaze to completion. Finally, when the head movement landed, it was almost aimed at the target and the eye had returned to within 10 +/- 7 degrees, mean +/- SD, of straight ahead. Between the end of the gaze shift and the end of the head movement, gaze remained stable in space or a small correction saccade occurred. 4. Gaze movements < 20 degrees landed accurately on target whether the head was fixed or free. For larger target movements, both head-free and head-fixed gaze shifts became increasingly hypometric. Head-free gaze shifts were more accurate, on average, but also more variable. This suggests that gaze is controlled in a different way with the head free. For target amplitudes < 60 degrees, head position was hypometric but the error was rather constant at approximately 10 degrees.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Automated Analysis of Body Movement in Emotionally Expressive Piano Performances

2008 ◽  
Vol 26 (2) ◽  
pp. 103-119 ◽  
Author(s):  
Ginevra Castellano ◽  
Marcello Mortillaro ◽  
Antonio Camurri ◽  
Gualtiero Volpe ◽  
Klaus Scherer
Keyword(s):  
Emotional Expression ◽  
Temporal Dynamics ◽  
Body Movement ◽  
Music Performance ◽  
The Body ◽  
Head Movements ◽  
Automated System ◽  
Upper Body ◽  
Musical Score ◽  
Motion Cues

EMOTIONAL EXPRESSION IN MUSIC PERFORMANCE includes important cues arising from the body movement of the musician. This movement is related to both the musical score execution and the emotional intention conveyed. In this experiment, a pianist was asked to play the same excerpt with different emotionally expressive intentions. The aim was to verify whether different expressions could be distinguished based on movement by trying to determine which motion cues were most emotion-sensitive. Analyses were performed via an automated system capable of detecting the temporal profiles of two motion cues: the quantity of motion of the upper body and the velocity of head movements. Results showed that both were sensitive to emotional expression, especially the velocity of head movements. Further, some features conveying information about movement temporal dynamics varied among expressive conditions allowing emotion discrimination. These results are in line with recent theories that underlie the dynamic nature of emotional expression.

Factors Affecting Remote Positioning Performance

1995 ◽  
Vol 39 (4) ◽  
pp. 282-286
Author(s):  
Shang H. Hsu ◽  
Chien C. Huang
Keyword(s):  
Movement Time ◽  
Interactive Effect ◽  
Vertical Movement ◽  
Movement Direction ◽  
Movement Amplitude ◽  
Distance Ratio ◽  
Factors Affecting ◽  
Fitts Law ◽  
Movement Distance ◽  
Two Measures

The purpose of this study was to investigate the effects of target width, movement direction, movement amplitude, and remote distance on remote positioning performance. Movement time and movement distance ratio were taken as measures of remote positioning performance. It was found that the effects of target width, movement amplitude, and movement direction on the two measures were significant. The effect of remote distance was significant only for movement distance ratio. The magnitude of the effect of target width on movement time was larger than that of movement amplitude; a modification of Fitts' Law was thus proposed. Moreover, there was an interactive effect between target width and movement direction- i.e., movement direction had an effect only when the target width was small. Among the eight movement directions, upward vertical movement was the best for remote positioning. The results shed some light onto the design of remote control user interface.

Disturbances in the Control of Saccadic Eye Movement and Eye-Head Coordination in Schizophrenics1

1991 ◽  
Vol 1 (2) ◽  
pp. 171-180
Author(s):  
Junko Fukushima ◽  
Kikuro Fukushima ◽  
Nobuyuki Morita ◽  
Itaru Yamashita
Keyword(s):  
Frontal Cortex ◽  
Head Movement ◽  
Head Movements ◽  
Saccadic Eye Movement ◽  
Antisaccade Task ◽  
Schizophrenic Patients ◽  
Saccade Task ◽  
Cortical Dysfunction ◽  
Reflexive Saccades ◽  
Target Memory

Some schizophrenic patients have been known to have frontal cortical dysfunction. In view of the evidence that voluntary purposive eye movements and rapid head movements involve areas of the frontal cortex, investigations of saccade performance have been carried out on schizophrenics in various laboratories. We have compared performance of schizophrenic patients in tasks involving inhibition of reflexive saccades (no-saccade) and initiation of saccades without target (memory-saccade) with performance in. the antisaccade task. These measures were also compared with results of eye-head coordination tasks. Schizophrenics showed more errors and significantly longer latencies, with lower peak velocities at large amplitudes, in both the anti saccade task and the memory-saccade task. Performance with coordinated eye-head movement was basically similar, except for significantly longer latencies of head movement. These results suggest that schizophrenics may have a disturbance in initiating and executing purposive saccades without targets, and that dysfunction of the frontal cortex may contribute to this disturbance.

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