scholarly journals Eye, Head, and Body Coordination During Large Gaze Shifts in Rhesus Monkeys: Movement Kinematics and the Influence of Posture

2007 ◽  
Vol 97 (4) ◽  
pp. 2976-2991 ◽  
Author(s):  
Meaghan K. McCluskey ◽  
Kathleen E. Cullen
Keyword(s):  
Rhesus Monkeys ◽  
Body Movement ◽  
Saccadic Eye Movements ◽  
The Body ◽  
Body Motion ◽  
Body Movements ◽  
Gaze Shifts ◽  
Gaze Shift ◽  
Sitting Posture ◽  
Neurophysiological Studies

Coordinated movements of the eye, head, and body are used to redirect the axis of gaze between objects of interest. However, previous studies of eye-head gaze shifts in head-unrestrained primates generally assumed the contribution of body movement to be negligible. Here we characterized eye-head-body coordination during horizontal gaze shifts made by trained rhesus monkeys to visual targets while they sat upright in a standard primate chair and assumed a more natural sitting posture in a custom-designed chair. In both postures, gaze shifts were characterized by the sequential onset of eye, head, and body movements, which could be described by predictable relationships. Body motion made a small but significant contribution to gaze shifts that were ≥40° in amplitude. Furthermore, as gaze shift amplitude increased (40–120°), body contribution and velocity increased systematically. In contrast, peak eye and head velocities plateaued at velocities of ∼250–300°/s, and the rotation of the eye-in-orbit and head-on-body remained well within the physical limits of ocular and neck motility during large gaze shifts, saturating at ∼35 and 60°, respectively. Gaze shifts initiated with the eye more contralateral in the orbit were accompanied by smaller body as well as head movement amplitudes and velocities were greater when monkeys were seated in the more natural body posture. Taken together, our findings show that body movement makes a predictable contribution to gaze shifts that is systematically influenced by factors such as orbital position and posture. We conclude that body movements are part of a coordinated series of motor events that are used to voluntarily reorient gaze and that these movements can be significant even in a typical laboratory setting. Our results emphasize the need for caution in the interpretation of data from neurophysiological studies of the control of saccadic eye movements and/or eye-head gaze shifts because single neurons can code motor commands to move the body as well as the head and eyes.

scholarly journals Effect of body movements in the venous blood flow and lymphatic circulation

2021 ◽  
Vol 6 (2) ◽  
Author(s):  
Eduardo Pinto-Ferreira
Keyword(s):  
Venous Thromboembolism ◽  
Body Movement ◽  
Venous Blood ◽  
The Body ◽  
Body Motion ◽  
Venous Stasis ◽  
Venous Blood Flow ◽  
Body Movements ◽  
Predisposing Factor ◽  
Lymphatic Circulation

The studies of ballistocardiography about the effect of cardiovascular activity in body motion raised the author interest in the research of the influence of body movements in the circulatory flow in venous and lymphatic vessels. These effects follow Sir Isaac Newton laws. With the body movement, the one-way valve structure of these vessels will cause a mobilization of venous blood and lymph to the proximal side. A model was built to demonstrate the effect of oscillatory movement in a liquid flow in a system of one-way valve. There was a rise of the liquid with difference in level that ranged from 9 cm up to 34 cm, depending on the amplitude and frequency. The model tried to mimic a segment of vein with its valve, and evaluate the effectiveness of oscillatory movements in the progression of the liquid, In a preliminary study, to assess the effect of oscillatory movements on leg swelling, this movements was applied in a clinical cases. There was regression of the oedema and circumference on the leg, by oscillatory movements, that was correlated with increase in lymphatic and venous drainage. Venous stasis is a predisposing factor of venous thromboembolism. How we extrapolate from the experimental model, the oscillatory movements of the legs improving venous circulation may contribute to the prophylaxis of venous thromboembolism. In conclusion, it is of interest to study its application in some situations of venous thromboembolism risk.

Perisaccadic Mislocalization of Visual Targets by Head-Free Gaze Shifts: Visual or Motor?

2008 ◽  
Vol 100 (4) ◽  
pp. 1848-1867 ◽  
Author(s):  
Sigrid M. C. I. van Wetter ◽  
A. John van Opstal
Keyword(s):  
Target Location ◽  
Saccadic Eye Movements ◽  
Open Loop ◽  
Spatial Updating ◽  
Gaze Shifts ◽  
Gaze Shift ◽  
The Gaze ◽  
Visual Probe ◽  
Saccade Onset ◽  
Saccade Direction

Such perisaccadic mislocalization is maximal in the direction of the saccade and varies systematically with the target-saccade onset delay. We have recently shown that under head-fixed conditions perisaccadic errors do not follow the quantitative predictions of current visuomotor models that explain these mislocalizations in terms of spatial updating. These models all assume sluggish eye-movement feedback and therefore predict that errors should vary systematically with the amplitude and kinematics of the intervening saccade. Instead, we reported that errors depend only weakly on the saccade amplitude. An alternative explanation for the data is that around the saccade the perceived target location undergoes a uniform transient shift in the saccade direction, but that the oculomotor feedback is, on average, accurate. This “ visual shift” hypothesis predicts that errors will also remain insensitive to kinematic variability within much larger head-free gaze shifts. Here we test this prediction by presenting a brief visual probe near the onset of gaze saccades between 40 and 70° amplitude. According to models with inaccurate gaze-motor feedback, the expected perisaccadic errors for such gaze shifts should be as large as 30° and depend heavily on the kinematics of the gaze shift. In contrast, we found that the actual peak errors were similar to those reported for much smaller saccadic eye movements, i.e., on average about 10°, and that neither gaze-shift amplitude nor kinematics plays a systematic role. Our data further corroborate the visual origin of perisaccadic mislocalization under open-loop conditions and strengthen the idea that efferent feedback signals in the gaze-control system are fast and accurate.

scholarly journals Target modality determines eye-head coordination in nonhuman primates: implications for gaze control

2011 ◽  
Vol 106 (4) ◽  
pp. 2000-2011 ◽  
Author(s):  
Luis C. Populin ◽  
Abigail Z. Rajala
Keyword(s):  
Nonhuman Primates ◽  
Saccadic Eye Movements ◽  
Head Movements ◽  
Gaze Shifts ◽  
Gaze Shift ◽  
The Gaze ◽  
Midbrain Structure ◽  
The Subject ◽  
Visual Targets ◽  
Time Of Presentation

We have studied eye-head coordination in nonhuman primates with acoustic targets after finding that they are unable to make accurate saccadic eye movements to targets of this type with the head restrained. Three male macaque monkeys with experience in localizing sounds for rewards by pointing their gaze to the perceived location of sources served as subjects. Visual targets were used as controls. The experimental sessions were configured to minimize the chances that the subject would be able to predict the modality of the target as well as its location and time of presentation. The data show that eye and head movements are coordinated differently to generate gaze shifts to acoustic targets. Chiefly, the head invariably started to move before the eye and contributed more to the gaze shift. These differences were more striking for gaze shifts of <20–25° in amplitude, to which the head contributes very little or not at all when the target is visual. Thus acoustic and visual targets trigger gaze shifts with different eye-head coordination. This, coupled to the fact that anatomic evidence involves the superior colliculus as the link between auditory spatial processing and the motor system, suggests that separate signals are likely generated within this midbrain structure.

Time Course of Vestibuloocular Reflex Suppression During Gaze Shifts

2004 ◽  
Vol 92 (6) ◽  
pp. 3408-3422 ◽  
Author(s):  
Kathleen E. Cullen ◽  
Marko Huterer ◽  
Danielle A. Braidwood ◽  
Pierre A. Sylvestre
Keyword(s):  
Short Duration ◽  
Rhesus Monkeys ◽  
Time Course ◽  
Normal Values ◽  
Behavioral Strategies ◽  
Gaze Shifts ◽  
Absolute Level ◽  
Gaze Shift ◽  
The Gaze ◽  
The Status

Although numerous investigations have probed the status of the vestibuloocular (VOR) during gaze shifts, its exact status remains strangely elusive. The goal of the present study was to precisely evaluate the dynamics of VOR suppression immediately before, throughout, and just after gaze shifts. A torque motor was used to apply rapid (100°/s), short-duration (20–30 ms) horizontal head perturbations in three Rhesus monkeys. The status of the VOR elicited by this transient head perturbation was first compared during 15, 40, and 60° gaze shifts. The level of VOR suppression just after gaze-shift onset (40 ms) increased with gaze-shift amplitude in two monkeys, approaching values of 80 and 35%. In contrast, in the third monkey, the VOR was not significantly attenuated for all gaze-shift amplitudes. The time course of VOR attenuation was then studied in greater detail for all three monkeys by imposing the same short-duration head perturbations 40, 100, and 150 ms after the onset of 60° gaze shifts. Overall we found a consistent trend, in which VOR suppression was maximal early in the gaze shift and progressively recovered to reach normal values near gaze-shift end. However, the high variability across subjects prevented establishing a unifying description of the absolute level and time course of VOR suppression during gaze shifts. We propose that differences in behavioral strategies may account, at least in part, for these differences between subjects.

scholarly journals Research on Non-Contact Monitoring System for Human Physiological Signal and Body Movement

Biosensors ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 58 ◽  
Author(s):  
Qiancheng Liang ◽  
Lisheng Xu ◽  
Nan Bao ◽  
Lin Qi ◽  
Jingjing Shi ◽  
...  
Keyword(s):  
Monitoring System ◽  
Doppler Radar ◽  
Body Movement ◽  
Radar System ◽  
The Body ◽  
Body Motion ◽  
Physiological Monitoring ◽  
Physiological Signal ◽  
Signal Monitoring ◽  
Monitoring Devices

With the rapid increase in the development of miniaturized sensors and embedded devices for vital signs monitoring, personal physiological signal monitoring devices are becoming popular. However, physiological monitoring devices which are worn on the body normally affect the daily activities of people. This problem can be avoided by using a non-contact measuring device like the Doppler radar system, which is more convenient, is private compared to video monitoring, infrared monitoring and other non-contact methods. Additionally real-time physiological monitoring with the Doppler radar system can also obtain signal changes caused by motion changes. As a result, the Doppler radar system not only obtains the information of respiratory and cardiac signals, but also obtains information about body movement. The relevant RF technology could eliminate some interference from body motion with a small amplitude. However, the motion recognition method can also be used to classify related body motion signals. In this paper, a vital sign and body movement monitoring system worked at 2.4 GHz was proposed. It can measure various physiological signs of the human body in a non-contact manner. The accuracy of the non-contact physiological signal monitoring system was analyzed. First, the working distance of the system was tested. Then, the algorithm of mining collective motion signal was classified, and the accuracy was 88%, which could be further improved in the system. In addition, the mean absolute error values of heart rate and respiratory rate were 0.8 beats/min and 3.5 beats/min, respectively, and the reliability of the system was verified by comparing the respiratory waveforms with the contact equipment at different distances.

Combined eye-head gaze shifts produced by electrical stimulation of the superior colliculus in rhesus monkeys

1996 ◽  
Vol 76 (2) ◽  
pp. 927-952 ◽  
Author(s):  
E. G. Freedman ◽  
T. R. Stanford ◽  
D. L. Sparks
Keyword(s):  
Rhesus Monkeys ◽  
Stimulation Frequency ◽  
Head Movements ◽  
Visually Guided ◽  
Maximal Amplitude ◽  
Gaze Shifts ◽  
Gaze Shift ◽  
Site Specific ◽  
Stimulation Parameters ◽  
Frequency Of Stimulation

1. We electrically stimulated the intermediate and deep layers of the superior colliculus (SC) in two rhesus macaques free to move their heads both vertically and horizontally (head unrestrained). Stimulation of the primate SC can elicit high-velocity, combined, eye-head gaze shifts that are similar to visually guided gaze shifts of comparable amplitude and direction. The amplitude of gaze shifts produced by collicular stimulation depends on the site of stimulation and on the parameters of stimulation (frequency, current, and duration of the stimulation train). 2. The maximal amplitude gaze shifts, produced by electrical stimulation at 56 sites in the SC of two rhesus monkeys, ranged in amplitude from approximately 7 to approximately 80 deg. Because the head was unrestrained, stimulation-induced gaze shifts often included movements of the head. Head movements produced at the 56 stimulation sites ranged in amplitude from 0 to approximately 70 deg. 3. The relationships between peak velocity and amplitude and between duration and amplitude of stimulation-induced head movements and gaze shifts were comparable with the relationships observed during visually guided gaze shifts. The relative contributions of the eyes and head to visually guided and stimulation-induced gaze shifts were also similar. 4. As was true for visually guided gaze shifts, the head contribution to stimulation-induced gaze shifts depended on the position of the eyes relative to the head at the onset of stimulation. When the eyes were deviated in the direction of the ensuing gaze shift, the head contribution increased and the latency to head movement onset was decreased. 5. We systematically altered the duration of stimulation trains (10-400 ms) while stimulation frequency and current remained constant. Increases in stimulation duration systematically increased the amplitude of the evoked gaze shift until a site specific maximal amplitude was reached. Further increases in stimulation duration did not increase gaze amplitude. There was a high correlation between the end of the stimulation train and the end of the evoked gaze shift for movements smaller than the site-specific maximal amplitude. 6. Unlike the effects of stimulation duration on gaze amplitude, the amplitude and duration of evoked head movements did not saturate for the range of durations tested (10-400 ms), but continued to increase linearly with increases in stimulation duration. 7. The frequency of stimulation was systematically varied (range: 63-1,000 Hz) while other stimulation parameters remained constant. The velocity of evoked gaze shifts was related to the frequency of stimulation; higher stimulation frequencies resulted in higher peak velocities. The maximal, site-specific amplitude was independent of stimulation frequency. 8. When stimulating a single collicular site using identical stimulation parameters, the amplitude and direction of stimulation-induced gaze shifts, initiated from different initial positions, were relatively constant. In contrast, the amplitude and direction of the eye component of these fixed vector gaze shifts depended upon the initial position of the eyes in the orbits; the endpoints of the eye movements converged on an orbital region, or "goal," that depended on the site of collicular stimulation. 9. When identical stimulation parameters were used and when the eyes were centered initially in the orbits, the gaze shifts produced by caudal collicular stimulation when the head was restrained were typically smaller than those evoked from the same site when the head was unrestrained. This attenuation occurred because stimulation drove the eyes to approximately the same orbital position when the head was restrained or unrestrained. Thus movements produced when the head was restrained were reduced in amplitude by approximately the amount that the head would have contributed if free to move. 10. When the head was restrained, only the eye component of the intended gaze shift

Screening Sleep Disordered Breathing with Noncontact Measurement in a Clinical Site

2017 ◽  
Vol 29 (2) ◽  
pp. 327-337 ◽  
Author(s):  
Yutaka Matsuura ◽  
◽  
Hieyong Jeong ◽  
Kenji Yamada ◽  
Kenji Watabe ◽  
...  
Keyword(s):  
Respiratory Rate ◽  
Sleep Disordered Breathing ◽  
Body Movement ◽  
The Body ◽  
Body Movements ◽  
Simple Method ◽  
Waveform Data ◽  
Respiratory Condition ◽  
Clinical Site ◽  
Disordered Breathing

[abstFig src='/00290002/06.jpg' width='300' text='Respiratory rate from simulator and Kinect' ]<span class=”bold”>Background and purpose:</span>It has been considered that sleep-disordered breathing disorders, such as sleep apnea syndrome (SAS), cause an increase in the risk of cardiovascular disease or traffic accident risk, and thus early detection of SAS is important. It has been also important for medical workers at clinical sites to quantitatively evaluate the respiratory condition of hospitalized patients who are asleep in a simple method. A noncontact-type system was proposed to monitor the respiratory condition of sleeping patients and minimized patient-related stress such that medical workers could use the system for SAS screening and perform a preliminary check prior to definite diagnosis.<span class=”bold”>Method:</span>The system included Microsoft Kinect™ for windows® (Kinect), a tripod, and a PC. A depth sensor of Kinect was used to measure movement in the thorax motion. Data obtained from periodic waveforms were divided with the intervals of 1 min, and the number of peaks was used to obtain the respiratory rate. Additionally, a frequency analysis was performed to calculate the respiratory frequency from a frequency at which the maximum amplitude was observed. In Experiment 1), a METI-man® PatientSimulator (CAE healthcare) (simulator) was used to study the respiratory rate and frequency calculated from the Kinect data by gradually changing the designated respiratory rate. In Experiment 2), the respiratory condition of four sleeping subjects was monitored to calculate their respiratory rate and frequencies. Furthermore, a video camera was used to confirm periodic waveforms and spectrum features of body movements during sleep.<span class=”bold”>Results:</span>In Experiment 1), the results indicated that both the respiratory rate and frequency corresponded to the designated respiratory rate in each time zone. In Experiment 2), the results indicated that the respiratory rate of examines 1, 2, 3, and 4 corresponded to 12.79±2.44 times/min (average ± standard deviation), 16.46±4.33 times/min, 28.24±2.79 times/min, and 13.05±2.64 times/min, respectively. The findings also indicated that the frequency of examines 1, 2, 3, and 4 corresponded to 0.20±0.04 Hz, 0.26±0.06 Hz, 0.45±0.12 Hz, and 0.22±0.06 Hz, respectively. The periodic waveforms and amplitude spectra were enhanced with respect to body movements although regular waveform data were obtained after the body movement occurred.<span class=”bold”>Discussions:</span>The results indicated that body movement and posture temporarily affected monitoring of the system. However, the findings also revealed that it was possible to calculate the respiratory rate and frequency, and thus it was considered that the system was useful for monitoring the respiration confirm with the non-contact or SAS screening of patients in clinical site.

scholarly journals Frames of Reference for Gaze Saccades Evoked During Stimulation of Lateral Intraparietal Cortex

2007 ◽  
Vol 98 (2) ◽  
pp. 696-709 ◽  
Author(s):  
A. G. Constantin ◽  
H. Wang ◽  
J. C. Martinez-Trujillo ◽  
J. D. Crawford
Keyword(s):  
Three Dimensional ◽  
Saccadic Eye Movements ◽  
Head Movements ◽  
Gaze Shifts ◽  
Gaze Shift ◽  
Lateral Intraparietal Cortex ◽  
The Gaze ◽  
The Right ◽  
Gaze Position ◽  
Stimulation Of

Previous studies suggest that stimulation of lateral intraparietal cortex (LIP) evokes saccadic eye movements toward eye- or head-fixed goals, whereas most single-unit studies suggest that LIP uses an eye-fixed frame with eye-position modulations. The goal of our study was to determine the reference frame for gaze shifts evoked during LIP stimulation in head-unrestrained monkeys. Two macaques ( M1 and M2) were implanted with recording chambers over the right intraparietal sulcus and with search coils for recording three-dimensional eye and head movements. The LIP region was microstimulated using pulse trains of 300 Hz, 100–150 μA, and 200 ms. Eighty-five putative LIP sites in M1 and 194 putative sites in M2 were used in our quantitative analysis throughout this study. Average amplitude of the stimulation-evoked gaze shifts was 8.67° for M1 and 7.97° for M2 with very small head movements. When these gaze-shift trajectories were rotated into three coordinate frames (eye, head, and body), gaze endpoint distribution for all sites was most convergent to a common point when plotted in eye coordinates. Across all sites, the eye-centered model provided a significantly better fit compared with the head, body, or fixed-vector models (where the latter model signifies no modulation of the gaze trajectory as a function of initial gaze position). Moreover, the probability of evoking a gaze shift from any one particular position was modulated by the current gaze direction (independent of saccade direction). These results provide causal evidence that the motor commands from LIP encode gaze command in eye-fixed coordinates but are also subtly modulated by initial gaze position.

Accommodation dynamics in aging rhesus monkeys

1998 ◽  
Vol 275 (6) ◽  
pp. R1885-R1897 ◽  
Author(s):  
Mary Ann Croft ◽  
Paul L. Kaufman ◽  
Kathryn S. Crawford ◽  
Michael W. Neider ◽  
Adrian Glasser ◽  
...  
Keyword(s):  
Steady State ◽  
Latent Period ◽  
Real Time ◽  
Ciliary Body ◽  
Rhesus Monkeys ◽  
Body Movement ◽  
Age Changes ◽  
Body Movements ◽  
Age Dependent ◽  
Body Motility

Accommodation, the mechanism by which the eye focuses on near objects, is lost with increasing age in humans and monkeys. This pathophysiology, called presbyopia, is poorly understood. We studied aging-related changes in the dynamics of accommodation in rhesus monkeys aged 4–24 yr after total iridectomy and midbrain implantation of an electrode to permit visualization and stimulation, respectively, of the eye’s accommodative apparatus. Real-time video techniques were used to capture and quantify images of the ciliary body and lens. During accommodation in youth, ciliary body movement was biphasic, lens movement was monophasic, and both slowed as the structures approached their new steady-state positions. Disaccommodation occurred more rapidly for both ciliary body and lens, but with longer latent period, and slowed near the end point. With increasing age, the amplitude of lens and ciliary body movement during accommodation declined, as did their velocities. The latent period of lens and ciliary body movements increased, and ciliary body movement became monophasic. The latent period of lens and ciliary body movement during disaccommodation was not significantly correlated with age, but their velocity declined significantly. The age-dependent decline in amplitude and velocity of ciliary body movements during accommodation suggests that ciliary body dysfunction plays a role in presbyopia. The age changes in lens movement could be a consequence of increasing inelasticity or hardening of the lens, or of age changes in ciliary body motility.

Respiratory consequences of passive body movement

1961 ◽  
Vol 16 (1) ◽  
pp. 30-34 ◽  
Author(s):  
M. E. Dixon ◽  
P. B. Stewart ◽  
F. C. Mills ◽  
C. J. Varvis ◽  
D. V. Bates
Keyword(s):  
Respiratory Rate ◽  
High Velocity ◽  
Body Movement ◽  
Normal Subjects ◽  
Upright Position ◽  
The Body ◽  
The Other ◽  
Metabolic Demand ◽  
Body Movements ◽  
End Tidal

The respiratory consequences of a number of passive body movements have been investigated in a group of normal subjects. It has been shown that certain types of torso movement produce hyperventilation in excess of metabolic demand, with a consequent lowering of end-tidal CO2 tension. Passive pedal motion of the legs did not produce this type of hyperventilation and concealed it if performed in conjunction with the other movements. The mechanism for the passive hyperventilation is not understood, since the respiratory rate did not appear to be rhythmically linked to the body movement, and certain maneuvers in the experiments did not affect the results. The level of hyperventilation that has been demonstrated is considered to be adequate to explain the phenomenon of hyperventilation which has been recorded in pilots flying high-velocity low-level aircraft, who may be subjected to considerable jolting while sitting in an upright position. Submitted on May 10, 1960

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