scholarly journals Mechanisms of punctuated vision in fly flight

2020 ◽  
Author(s):  
Benjamin Cellini ◽  
Wael Salem ◽  
Jean-Michel Mongeau
Keyword(s):  
Active Vision ◽  
Causal Link ◽  
Head Movements ◽  
Flight Simulator ◽  
Head Orientation ◽  
Eye Position ◽  
Elastic Recoil ◽  
Motor Tasks ◽  
Gaze Stabilization ◽  
Complex Motor

ABSTRACTTo guide locomotion, animals control their gaze via movements of their eyes, head, and/or body, but how the nervous system controls gaze during complex motor tasks remains elusive. Notably, eye movements are constrained by anatomical limits, which requires resetting eye position. By studying tethered, flying flies (Drosophila) in a virtual reality flight simulator, we show that ballistic head movements (saccades) reset eye position, are stereotyped and leverage elastic recoil of the neck joint, enabling mechanically assisted redirection of gaze. Head reset saccades were of proprioceptive origin and interrupted smooth movements for as little as 50 ms, enabling punctuated, near-continuous gaze stabilization. Wing saccades were modulated by head orientation, establishing a causal link between neck signals and execution of body saccades. Furthermore, we demonstrate that head movements are gated by behavioral state. We propose a control architecture for biological and bio-inspired active vision systems with limits in sensor range of motion.

scholarly journals An ultralight head-mounted camera system integrates detailed behavioral monitoring with multichannel electrophysiology in freely moving mice

2018 ◽  
Author(s):  
Arne F. Meyer ◽  
Jasper Poort ◽  
John O’Keefe ◽  
Maneesh Sahani ◽  
Jennifer F. Linden
Keyword(s):  
Neural Circuit ◽  
Model Organism ◽  
Neural Recording ◽  
Head Movements ◽  
Head Orientation ◽  
Eye Position ◽  
Neural Basis ◽  
Camera System ◽  
Recording Technology ◽  
Behavioral Monitoring

SummaryBreakthroughs in understanding the neural basis of natural behavior require neural recording and intervention to be paired with high-fidelity multimodal behavioral monitoring. An extensive genetic toolkit for neural circuit dissection, and well-developed neural recording technology, make the mouse a powerful model organism for systems neuroscience. However, methods for high-bandwidth acquisition of behavioral signals in mice remain limited to fixed-position cameras and other off-animal devices, complicating the monitoring of animals freely engaged in natural behaviors. Here, we report the development of an ultralight head-mounted camera system combined with head-movement sensors to simultaneously monitor eye position, pupil dilation, whisking, and pinna movements along with head motion in unrestrained, freely behaving mice. The power of the combined technology is demonstrated by observations linking eye position to head orientation; whisking to non-tactile stimulation; and, in electrophysiological experiments, visual cortical activity to volitional head movements.

scholarly journals COMPARATIVE MEASUREMENTS OF HEAD ANGULAR MOVEMENTS USING A CAMERA SYSTEM AND A GYROSCOPE SYSTEM

2014 ◽  
Vol 54 (4) ◽  
pp. 295-300 ◽  
Author(s):  
Vladimir Socha ◽  
Patrik Kutilek ◽  
Ondrej Cakrt ◽  
Rudolf Cerny
Keyword(s):  
Head Movements ◽  
Head Orientation ◽  
Quiet Stance ◽  
Body Segment ◽  
Mean Velocity ◽  
Camera System ◽  
Rehabilitation Process ◽  
Gyroscope System ◽  
The Mean ◽  
2D Data

Assessments of body-segment angular movements are very important in the rehabilitation process. Head angular movements are measured and analyzed for use in studies of stability and posture. However, there is no methodology for assessing angular movements of the head, and it has not been verified whether data measured by fundamentally different MoCap systems will lead to the same results. In this study, we used a camera system and a 3DOF orientation tracker placed on the subject’s head, and measured inclination (roll) and flexion (pitch) during quiet stance. The total length and the mean velocity of the traces of the pitch versus roll plots were used to measure and analyze head orientation. Using these methods, we are able to model the distribution of the measured 2D data, and to evaluate stability and posture. The results show that the total lengths and the mean velocities related to the 3DOF orientation tracker do not differ significantly from the total lengths and the mean velocities of traces related to the IR medical camera. We also found that the systems are not interchangeable, and that the same type of system must be used each time. The designed methods can be used for studies not only of head movements but also of movements of other segments of the human body, and can be used to compare other types of MoCap systems, depending on the requirements for a specific rehabilitation examination.

Viewing Target Distance Influences the Vestibulo-Ocular Reflex Gain when Assessed Using the Video Head Impulse Test

2018 ◽  
Vol 23 (5) ◽  
pp. 285-289 ◽  
Author(s):  
Patricia Castro ◽  
Sara Sena Esteves ◽  
Florencia Lerchundi ◽  
David Buckwell ◽  
Michael A. Gresty ◽  
...  
Keyword(s):  
Head Movements ◽  
Target Distance ◽  
Head Impulse Test ◽  
Video Head Impulse Test ◽  
Gaze Stabilization ◽  
Head Impulse ◽  
Ocular Reflex ◽  
Significant Difference ◽  
Vestibulo Ocular Reflex ◽  
Reflex Gain

Gaze stabilization during head movements is provided by the vestibulo-ocular reflex (VOR). Clinical assessment of this reflex is performed using the video Head Impulse Test (vHIT). To date, the influence of different fixation distances on VOR gain using the vHIT has not been explored. We assessed the effect of target proximity on the horizontal VOR using the vHIT. Firstly, we assessed the VOR gain in 18 healthy subjects with 5 viewing target distances (150, 40, 30, 20, and 10 cm). The gain increased significantly as the viewing target distance decreased. A second experiment on 10 subjects was performed in darkness whilst the subjects were imagining targets at different distances. There were significant inverse relationships between gain and distance for both the real and the imaginary targets. There was a statistically significant difference between light and dark gains for the 20- and 40-cm distances, but not for the 150-cm distance. Theoretical VOR gains for different target distances were calculated and compared with those found in light and darkness. The increase in gain observed for near targets was lower than predicted by geometrical calculations, implying a physiological ceiling effect on the VOR. The VOR gain in the dark, as assessed with the vHIT, demonstrates an enhancement associated with a reduced target distance.

scholarly journals Dynamics of gaze control during prey capture in freely moving mice

2020 ◽  
Author(s):  
Angie M. Michaiel ◽  
Elliott T.T. Abe ◽  
Cristopher M. Niell
Keyword(s):  
Eye Movements ◽  
Visual Processing ◽  
Visual Information ◽  
Prey Capture ◽  
Active Vision ◽  
Head Movements ◽  
Visual Scene ◽  
Specific Point ◽  
Binocular Field ◽  
Freely Moving

ABSTRACTMany studies of visual processing are conducted in unnatural conditions, such as head- and gaze-fixation. As this radically limits natural exploration of the visual environment, there is much less known about how animals actively use their sensory systems to acquire visual information in natural, goal-directed contexts. Recently, prey capture has emerged as an ethologically relevant behavior that mice perform without training, and that engages vision for accurate orienting and pursuit. However, it is unclear how mice target their gaze during such natural behaviors, particularly since, in contrast to many predatory species, mice have a narrow binocular field and lack foveate vision that would entail fixing their gaze on a specific point in the visual field. Here we measured head and bilateral eye movements in freely moving mice performing prey capture. We find that the majority of eye movements are compensatory for head movements, thereby acting to stabilize the visual scene. During head turns, however, these periods of stabilization are interspersed with non-compensatory saccades that abruptly shift gaze position. Analysis of eye movements relative to the cricket position shows that the saccades do not preferentially select a specific point in the visual scene. Rather, orienting movements are driven by the head, with the eyes following in coordination to sequentially stabilize and recenter the gaze. These findings help relate eye movements in the mouse to other species, and provide a foundation for studying active vision during ethological behaviors in the mouse.

Context Compensation in the Vestibuloocular Reflex During Active Head Rotations

2000 ◽  
Vol 84 (6) ◽  
pp. 2904-2917 ◽  
Author(s):  
W. P. Medendorp ◽  
J.A.M. Van Gisbergen ◽  
S. Van Pelt ◽  
C.C.A.M. Gielen
Keyword(s):  
Human Subjects ◽  
Linear Regression Analysis ◽  
Head Movements ◽  
Target Distance ◽  
General Context ◽  
Vestibuloocular Reflex ◽  
Gaze Stabilization ◽  
Retinal Slip ◽  
Eye Velocity ◽  
Head Rotations

The vestibuloocular reflex (VOR) needs to modulate its gain depending on target distance to prevent retinal slip during head movements. We investigated gain modulation (context compensation) for binocular gaze stabilization in human subjects during voluntary yaw and pitch head rotations. Movements of each eye were recorded, both when attempting to maintain gaze on a small visual target at straight-ahead in a darkened room and after its disappearance (remembered target). In the analysis, we relied on a binocular coordinate system yielding a version and a vergence component. We examined how frequency and target distance, approached here by using vergence angle, affected the gain and phase of the version component of the VOR and compared the results to the requirements for ideal performance. Linear regression analysis on the version gain-vergence relationship yielded a slope representing the influence of target proximity and an intercept corresponding to the response at zero vergence (“default gain”). The slope of the fitted relationship, divided by the geometrically required slope, provided a measure for the quality of version context compensation (“context gain”). In both yaw and pitch experiments, we found default version gains close to one even for the remembered target condition, indicating that the active VOR for far targets is already close to ideal without visual support. In near target experiments, the presence of visual feedback yielded near unity context gains, indicating close to optimal performance (retinal slip <0.4°/s). For remembered targets, the context gain deteriorated but was still superior to performance in corresponding passive studies reported in the literature. In general, context compensation in the remembered target paradigm was better for vertical than for horizontal head rotations. The phase delay of version eye velocity relative to head velocity was small (∼2°) for both horizontal and vertical head movements. Analysis of the vergence data from the near target experiments showed that context compensation took into account that the two eyes require slightly different VORs. In thediscussion, comparison of the present default VOR gains and context gains with data from earlier passive studies has led us to propose a limited role for efference copies during self-generated movements. We also discuss how our analysis can provide a framework for evaluating two different hypotheses for the generation of binocular VOR eye movements.

A 6-dof device to measure head movements in active vision experiments: geometric modeling and metric accuracy

1999 ◽  
Vol 90 (2) ◽  
pp. 97-106 ◽  
Author(s):  
F. Panerai ◽  
S. Hanneton ◽  
J. Droulez ◽  
V. Cornilleau-Pérès
Keyword(s):  
Geometric Modeling ◽  
Active Vision ◽  
Head Movements

scholarly journals Kinematic Principles of Primate Rotational Vestibulo-Ocular Reflex II. Gravity-Dependent Modulation of Primary Eye Position

1997 ◽  
Vol 78 (4) ◽  
pp. 2203-2216 ◽  
Author(s):  
Bernhard J. M. Hess ◽  
Dora E. Angelaki
Keyword(s):  
Slow Phase ◽  
Head Orientation ◽  
Eye Position ◽  
Single Plane ◽  
Fast Phase ◽  
Ocular Reflex ◽  
Listing's Plane ◽  
Vestibulo Ocular Reflex ◽  
Torsional Component ◽  
Listing’S Plane

Hess, Bernhard J. M. and Dora E. Angelaki. Kinematic principles of primate rotational vestibulo-ocular reflex. II. Gravity-dependent modulation of primary eye position. J. Neurophysiol. 78: 2203–2216, 1997. The kinematic constraints of three-dimensional eye positions were investigated in rhesus monkeys during passive head and body rotations relative to gravity. We studied fast and slow phase components of the vestibulo-ocular reflex (VOR) elicited by constant-velocity yaw rotations and sinusoidal oscillations about an earth-horizontal axis. We found that the spatial orientation of both fast and slow phase eye positions could be described locally by a planar surface with torsional variation of <2.0 ± 0.4° (displacement planes) that systematically rotated and/or shifted relative to Listing's plane. In supine/prone positions, displacement planes pitched forward/backward; in left/right ear-down positions, displacement planes were parallel shifted along the positive/negative torsional axis. Dynamically changing primary eye positions were computed from displacement planes. Torsional and vertical components of primary eye position modulated as a sinusoidal function of head orientation in space. The torsional component was maximal in ear-down positions and approximately zero in supine/prone orientations. The opposite was observed for the vertical component. Modulation of the horizontal component of primary eye position exhibited a more complex dependence. In contrast to the torsional component, which was relatively independent of rotational speed, modulation of the vertical and horizontal components of primary position depended strongly on the speed of head rotation (i.e., on the frequency of oscillation of the gravity vector component): the faster the head rotated relative to gravity, the larger was the modulation. Corresponding results were obtained when a model based on a sinusoidal dependence of instantaneous displacement planes (and primary eye position) on head orientation relative to gravity was fitted to VOR fast phase positions. When VOR fast phase positions were expressed relative to primary eye position estimated from the model fits, they were confined approximately to a single plane with a small torsional standard deviation (∼1.4–2.6°). This reduced torsional variation was in contrast to the large torsional spread (well >10–15°) of fast phase positions when expressed relative to Listing's plane. We conclude that primary eye position depends dynamically on head orientation relative to space rather than being fixed to the head. It defines a gravity-dependent coordinate system relative to which the torsional variability of eye positions is minimized even when the head is moved passively and vestibulo-ocular reflexes are evoked. In this general sense, Listing's law is preserved with respect to an otolith-controlled reference system that is defined dynamically by gravity.

Increased cognitive load during simple and complex motor tasks in acute stage after stroke

2007 ◽  
Vol 63 (2) ◽  
pp. 173-180 ◽  
Author(s):  
Urška Puh ◽  
Andrej Vovk ◽  
France Sevšek ◽  
Dušan Šuput
Keyword(s):  
Cognitive Load ◽  
Acute Stage ◽  
Motor Tasks ◽  
Complex Motor

scholarly journals Thermal reception in the Mexican Lance-head rattlesnake, Crotalus polystictus

2018 ◽  
Author(s):  
Octavio I Martínez Vaca-León ◽  
Javier Manjarrez
Keyword(s):  
Behavioral Response ◽  
Head Movements ◽  
Head Orientation ◽  
Thermal Thresholds ◽  
Interspecific Differences ◽  
Neurophysiological Mechanisms ◽  
Thermal Detection ◽  
Tongue Flicks ◽  
Thermal Stimuli ◽  
Stimulus Shape

The sensory systems of Boidae and Crotalinae snakes detect subtle differences of thermal infrared energy. The complexity of this ability involves neurophysiological mechanisms with interspecific differences in the anatomy of thermoreceptor organs and functionally in thermal detection ranges and thermal thresholds, with ecological correlations that influence the thermo-reception. However, little is known about the information these snakes obtain and use from infrared radiation. We analyzed the behavioral response of adult Mexican Lance-head Rattlesnakes (Crotalus polystictus) to static thermal stimuli, evaluating the influence of distance from the snake of the thermal stimuli, and its lizard-like or mouse-like shape. The results reveal that C. polystictus is able to detect static thermal stimuli located from 20 to 200 cm away. Head movements and tongue-flicks were the most frequently performed behaviors, which suggests they are behaviors that can facilitate the detection of subtle differences in temperature of static stimuli. In addition, we suggest that stimulus shape and temperature are important in the timing of head orientation and frequency of tongue-flicks. We discuss the possible methodological and sensory implications of this behavioral response in C. polystictus.

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