Monocular Egocentric Distance Information Generated by Head Movement

Event Abstract Back to Event Head – Body coordination in Drosophila melanogaster Bart R. Geurten1*, Philipp Jähde1 and Martin C. Göpfert1 1 Georg-August University of Göttingen, Department of Cellular Neurobiology, Germany Drosophila melanogaster like many other insects organises its locomotion in prolonged phases of translational movement that are interspersed by fast rotations called saccades. This saccadic locomotion strategy, which is found in insects and vertebrates (Collett and Land 1975; Boeddeker et al. 2010; Ribak, Egge, and Swallow 2009; Geurten et al. 2010; Eckmeier et al. 2008) is believed to enhance the 3D-information in visual perception. Schilstra and van Hateren documented that the head of blowflies rotates even faster than the body (Schilstra and Hateren 1999; Hateren and Schilstra 1999), further reducing the effective duration of the saccade. We tracked freely walking Drosophila melanogaster and found that they intersperse translational movements with fast saccadic rotations, similar as reported for blowflies by Blaj and van Hateren (Blaj and Van Hateren 2004). Reconstructing the head and body movements from high-speed recordings revealed that unlike blowflies, Drosophila does not move its head relative to the thorax during the saccades, which thus represent pure ‘body’ saccades. Even though single saccadic movements of the head were observed, saccadic yaw movements seem to be governed by a different behavioural strategy than in walking Calliphora. By modelling the visual input, we found that unlike blowflies, Drosophila would not profit from additional head rotations because of the lower spatial acuity of its eyes. This explains why Drosophila performs pure body saccades – during walking and presumably also during flight. References Blaj, G, and J H van Hateren. 2004. “Saccadic Head and Thorax Movements in Freely Walking Blowflies.” Journal of Comparative Physiology. A, Neuroethology, Sensory, Neural, and Behavioral Physiology 190 (11) (November): 861–868. Boeddeker, Norbert, Laura Dittmar, Wolfgang Stürzl, and Martin Egelhaaf. 2010. “The Fine Structure of Honeybee Head and Body Yaw Movements in a Homing Task.” Proceedings. Biological Sciences / The Royal Society 277 (1689) (June 22): 1899–1906. Collett, T.S., and M.F. Land. 1975. “Visual Control of Flight Behaviour in the Hoverfly Syritta Pipiens L.” Journal of Comparative Physiology A: Neuroethology, Sensory, Neural, and Behavioral Physiology V99 (1) (March): 1–66. Eckmeier, D., B.R.H. Geurten, D. Kress, M. Mertes, R. Kern, M. Egelhaaf, and H.J. Bischof. 2008. “Gaze Strategy in the Free Flying Zebra Finch (Taeniopygia Guttata).” PLoS ONE 3 (12) (December): e3956. Geurten, Bart R. H., Roland Kern, Elke Braun, and Martin Egelhaaf. 2010. “A Syntax of Hoverfly Flight Prototypes.” Journal of Experimental Biology 213 (14) (July 15): 2461–2475. Hateren, JH, and C Schilstra. 1999. “Blowfly Flight and Optic Flow. II. Head Movements During Flight.” Journal of Experimental Biology 202 (11) (June 1): 1491–1500. Ribak, Gal, Alison R. Egge, and John G. Swallow. 2009. “Saccadic Head Rotations During Walking in the Stalk-eyed Fly (Cyrtodiopsis Dalmanni).” Proceedings of the Royal Society B: Biological Sciences. Schilstra, C., and J.H. van Hateren. 1999. “Blowfly Flight and Optic Flow I. Thorax Kinematics and Flight Dynamics.” Journal of Experimental Biology 202 (11) (June): 1481–1490. Keywords: motion vision, Drosophila melanogaster, saccade, Neuroethology, Visual Acuity Conference: International Conference on Invertebrate Vision, Fjälkinge, Sweden, 1 Aug - 8 Aug, 2013. Presentation Type: Poster presentation preferred Topic: Motion vision Citation: Geurten BR, Jähde P and Göpfert MC (2019). Head – Body coordination in Drosophila melanogaster. Front. Physiol. Conference Abstract: International Conference on Invertebrate Vision. doi: 10.3389/conf.fphys.2013.25.00055 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 28 Feb 2013; Published Online: 09 Dec 2019. * Correspondence: Dr. Bart R Geurten, Georg-August University of Göttingen, Department of Cellular Neurobiology, Göttingen, 37077, Germany, bgeurte@gwdg.de Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Bart R Geurten Philipp Jähde Martin C Göpfert Google Bart R Geurten Philipp Jähde Martin C Göpfert Google Scholar Bart R Geurten Philipp Jähde Martin C Göpfert PubMed Bart R Geurten Philipp Jähde Martin C Göpfert Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Previous work in automatic affect analysis (AAA) has emphasized static expressions to the neglect of the dynamics of facial movement and considered head movement only a nuisance variable to control. We investigated whether the dynamics of head and facial movements apart from specific facial expressions communicate affect in infants, an under-studied population in AAA. Age-appropriate tasks were used to elicit positive and negative affect in 31 ethnically diverse infants. 3D head and facial movements were tracked from 2D video. Head angles in the horizontal (pitch), vertical (yaw), and lateral (roll) directions were used to measure head movement; and the 3D coordinates of 49 facial points to measure facial movements. Strong effects were found for both head and facial movements. Angular velocity and angular acceleration of head pitch, yaw, and roll were higher during negative relative to positive affect. Amplitude, velocity, and acceleration of facial movement were higher as well during negative relative to positive affect. A linear discriminant analysis using head and facial movement achieved a mean classification rate of positive and negative affect equal to 65% (Kappa = 0.30). Head and facial movement individually and in combination were also strongly related to observer ratings of affect intensity. Our results suggests that the dynamics of head and facial movements communicate affect at ages as young as 13 months. These interdisciplinary findings from behavioral science and computer vision deepen our understanding of communication of affect and provide a basis for studying individual differences in emotion in socio-emotional development.

Head direction (HD) neurons fire selectively according to head orientation in the yaw plane relative to environmental landmark cues. Head movements provoke optic field flow signals that enter the vestibular nuclei, indicating head velocity, and hence angular displacements. To test whether optic field flow alone affects the directional firing of HD neurons, rats walked about on a circular platform as a spot array was projected onto the surrounding floor-to-ceiling cylindrical black curtain. Directional responses in the anterodorsal thalamus of four rats remained stable as they moved about with the point field but in the absence of landmark cues. Then, the spherical projector was rotated about its yaw axis at 4.5°/s for ∼90 s. In 27 sessions the mean drift speed of the preferred directions (PDs) was 1.48°/s (SD=0.78°/s; range: 0.15 to 2.88°/s). Thus, optic flow stimulation entrained PDs, albeit at drift speeds slower than the field rotation. This could be due to conflicts with vestibular, motor command, and efferent copy signals. After field rotation ended, 20/27 PDs drifted back to within 45° of the initial values over several minutes, generally following the shortest path to return to the initial value. Poststimulation drifts could change speed and/or direction, with mean speeds of 0.68±0.64°/s (range 0 to 1.36°/s). Since the HD cell pathway (containing anterodorsal thalamus) is the only known projection of head direction information to entorhinal grid cells and hippocampal place cells, yaw plane optic flow signals likely influence representations in this spatial reference coordinate system for orientation and navigation.

Amplitudes of head movements during putative eye-only saccades

There is considerable support for the hypothesis that perception of heading in the presence of rotation is mediated by instantaneous optic flow. This hypothesis, however, has never been tested. We introduce a method, termed "nonvarying phase motion," for generating a stimulus that conveys a single instantaneous optic flow field, even though the stimulus is presented for an extended period of time. In this experiment, observers viewed stimulus videos and performed a forced-choice heading discrimination task. For nonvarying phase motion, observers made large errors in heading judgments. This suggests that instantaneous optic flow is insufficient for heading perception in the presence of rotation. These errors were mostly eliminated when the velocity of phase motion was varied over time to convey the evolving sequence of optic flow fields corresponding to a particular heading. This demonstrates that heading perception in the presence of rotation relies on the time-varying evolution of optic flow. We hypothesize that the visual system accurately computes heading, despite rotation, based on optic acceleration, the temporal derivative of optic flow.

Most moving animals segregate their locomotion trajectories in short burst like rotations and prolonged translations, to enhance distance information from optic flow, as only translational, but not rotational optic flow holds distance information. Underwater, optic flow is a valuable source of information as it is in the terrestrial habitat, however, so far, it has gained only little attention. To extend the knowledge on underwater optic flow perception and use, we filmed the movement pattern of six common cuttlefish (Sepia officinalis) with a high speed camera in this study. In the subsequent analysis, the center of mass of the cuttlefish body was manually traced to gain thrust, slip, and yaw of the cuttlefish movements over time. Cuttlefish indeed performed short rotations, saccades, with rotational velocities up to 343°/s. They clearly separated rotations from translations in line with the saccadic movement strategy documented for animals inhabiting the terrestrial habitat as well as for the semiaquatic harbor seals before. However, this separation only occurred during fin motion. In contrast, during jet propelled swimming, the separation between rotational and translational movements and thus probably distance estimation on the basis of the optic flow field is abolished in favor of high movement velocities. In conclusion, this study provides first evidence that an aquatic invertebrate, the cuttlefish, adopts a saccadic movement strategy depending on the behavioral context that could enhance the information gained from optic flow.

The accuracy of pointing movements of the hand, directed at visual targets 10 degrees to 40 degrees from the midline, was measured in normal human subjects. No visual feedback from the moving hand was available to the subjects. The head could be either maintained stationary (head-fixed condition) or free to move (head-free condition) during the pointing movements. It was found that the error in pointing was reduced for all targets in the head-free condition. This reduction was more important for the more eccentric target (40 degrees). Improvement in accuracy was observed without any significant change in either the latency or the duration of eye, head or hand movements. In the head-free condition, it was found that the head was displaced in the direction of the target by an amount representing no more than 2/3 of the target amplitude. The improvement in accuracy was not influenced by the amplitude of the head movement. A model is proposed which shows how coordinated eye and head movements could improve the encoding of target position.

Two monkeys were trained to track a continuously moving target using a joystick. One then had a cooling probe implanted in nucleus interpositus of the cerebellum ipsilateral to his tracking arm. The other had a cannula implanted in the ipsilateral cortex of the lateral cerebellum through which local anaesthetic could be infused. Both monkeys showed similar tracking deficits during temporary inactivation of the cerebellum. The main effects seen were an increase in the peak velocity of their intermittent corrective tracking movements, and a decrease in the accuracy of these movements. Linear regression analyses were undertaken of the peak velocity and amplitude of each corrective movement against a number of possible control signals (target velocity, target position, error, error velocity etc.). The initially strong correlation of the amplitude of each movement made with target velocity was severely reduced during cerebellar inactivation, and movement amplitude became better predicted by the error between target and joystick positions. The peak velocity of movements became more strongly correlated with movement amplitude and less correlated with target velocity than in the intact animal. These results are consistent with the hypothesis that intermittent tracking is achieved by the production of 'primitive' movements, that are then adjusted to the correct amplitude and velocity required to catch up with the moving target. Our findings suggest that the cerebellum may normally be responsible for these adjustments, using visual and memorised cues about the target. The velocity of each movement may be reduced, and its amplitude adjusted, by combining measures of the current error with estimates of target speed and direction. We conclude that the cerebellum has an inhibitory role in tuning movements during visuo-motor tasks and that optimal tuning using feedforward measurements of target motion cannot be made without it.

Humans make systematic errors in the 3D interpretation of the optic flow in both passive and active vision. These systematic distortions can be predicted by a biologically-inspired model which disregards self-motion information resulting from head movements (Caudek, Fantoni, & Domini 2011). Here, we tested two predictions of this model: (1) A plane that is stationary in an earth-fixed reference frame will be perceived as changing its slant if the movement of the observer's head causes a variation of the optic flow; (2) a surface that rotates in an earth-fixed reference frame will be perceived to be stationary, if the surface rotation is appropriately yoked to the head movement so as to generate a variation of the surface slant but not of the optic flow. Both predictions were corroborated by two experiments in which observers judged the perceived slant of a random-dot planar surface during egomotion. We found qualitatively similar biases for monocular and binocular viewing of the simulated surfaces, although, in principle, the simultaneous presence of disparity and motion cues allows for a veridical recovery of surface slant.

In birds, optic flow is analyzed by two retinal-recipient nuclei: the nucleus of the basal optic root (nBOR) of the accessory optic system (AOS), and the pretectal nucleus, lentiformis mesencephali (LM). Previous anatomical studies have shown that both of these nuclei have descending projections to structures involved in oculomotor, head movement, and postural control. In this report, using biotinylated dextran amine (BDA) and cholera toxin subunit B (CTB) for anterograde and retrograde labelling, respectively, we investigated projections from the nBOR and LM to the dorsal thalamus. After injections of BDA into the nBOR and LM, terminals were consistently found in the nucleus dorsolateralis anterior pars lateralis and pars medialis, and the nucleus dorsalis intermedius ventralis anterior of the thalamus. Some terminals were also found in the nucleus dorsolateralis anterior, nucleus dorsomedialis anterior pars magnocellularis, nucleus dorsolateralis posterior, nucleus superficialis parvocellularis, and the ventrointermediate area. Injections of CTB into the dorsal thalamus resulted in retrogradely labelled cells in the pretectal region, including LM. Numerous cells were also seen in the nBOR pars lateralis and pars dorsalis, but fewer were seen in the nBOR proper. We suggest that the AOS is providing input to a thalamotelencephalic system that may be involved in several functions including: (1) multi-sensory analysis of self-motion, (2) perception of self-motion, (3) perception of the three-dimensional layout of the environment, (4) distinguishing object-motion from self-motion, and (5) spatial cognition.

Vision is arguably our premier navigational aid, allowing us to map out and actively explore our surroundings. However, we view the world from a constantly shifting platform and some visual mechanisms function optimally only if the images on the retina are reasonably steady. As we go about our everyday activities, visual and vestibular mechanisms help to stabilize our gaze on particular objects of interest by generating eye movements to offset our head movements. The general picture that has emerged of gaze stabilization in primates during motion is of two vestibulo-ocular reflexes, the RVOR and TVOR, that compensate selectively for rotational and translational disturbances of the head, respectively, each with its own independent visual backup mechanisms. A major objective of this chapter is to review recent work on low-level, pre-attentive mechanisms that operate with ultra-short latencies and are largely independent of conscious perception. Recent advances in the field of robotics and, particularly, in the domain of active vision, provide a complementary view of the uses and associated problems of visuo-inertial integration for the stabilization of gaze. Much like biological systems, robots have to comply with physical constraints imposed by the environment and/or by the need to coordinate their sensori-motor components in an efficient way. In contrast with biological systems, however, the experimental variation of implementation parameters and control strategies allows, among other things, a comparison of the different hypotheses and implementations. The goal of this chapter is to draw parallels between the results from biology and from a robot which uses inertial and visual information to stabilize its cameras/eyes. The Chapter is organized as follows. Section 2 describes the peculiarities of the patterns of retinal motion (optic flow) experienced by an observer moving through the environment. The appropriate compensatory eye movements required to stabilize gaze are described in Section 3, introducing the distinction between vergence and version eye movements. Section 4 describes the main characteristics of the vestibular system from a biological and artificial perspective and the distinction between “rotational” and “translational” components of the vestibulo-ocular reflex (VOR). The magnitude of the eye movements required for complete compensation depends on various kinematic parameters such as the position of the eyes in the head, the inter-ocular distance, as well as the distance to the fixation point. Section 5 deals with the integration of visual and inertial information for gaze stabilization. This Section builds upon the concept of “translational” and “rotational” components of the VOR and highlights the differences between “version” and “vergence” control of compensatory eye movements. In particular the role of the radial component of optical flow in the feed-forward control of eye movements is compared with the feed-back loop mediated by binocular disparity. In Section 6, the contribution of inertial and visual information in gaze stabilization is discussed with reference to the different latencies and processing power required by the two modalities. The advantage of the integration of visual and inertial data is discussed from a biological and robotics perspective in the concluding Section.

Human mandibular movements in space are the result of combined motions of the mandible and the head-neck. They can be simultaneously monitored by an optoelectronic recording technique via markers at different locations on the mandible and on the head. Markers can be attached to the teeth or to the facial skin. Mandibular movements relative to the head can be calculated by one- or three-dimensional (1D and 3D, respectively) mathematical compensation for head movements. The present study analysed mandibular and associated head movements during maximal jaw opening-closing tasks in 10 healthy subjects using a wireless 3D optoelectronic movement recording system. The study aimed to: (i) estimate the soft tissue related displacement of skin-attached markers at different locations on the face; (ii) compare 1D with 3D mathematical compensation for associated head movements; (iii) evaluate the influence of marker location on the recorded head and mandibular movement amplitudes; and (iv) compare skin-attached markers with teeth-attached markers with regard to temporal estimates of recorded mandibular and head movements. Markers were attached to the upper and lower incisors and to the skin of the forehead, nose-bridge, nose-tip and chin. Soft tissue related displacement of skin-attached markers varied between locations. The displacement for the chin marker was larger than that of other markers. The least displacement was found for the nose-bridge marker. However, relative to mandibular and head movements, respectively, the displacement of the chin marker was of the same order as that of the nose-bridge marker. The temporal estimates were not significantly affected by displacement of the skin-attached markers. Markers at different locations on the head and the mandible registered different amplitudes. The mandibular movement patterns calculated by 1D and 3D compensation were not comparable. It is concluded that markers attached to the chin and the nose-bridge can be reliably used in temporal analyses of mandibular and head movements during maximal jaw opening-closing. With certain limitations, they are acceptable for spatial analyses. Selection of method of marker attachment, marker location, and method of compensation for associated head movements should be based on the aim of the study.

Why are voluntary head movements in cervical dystonia slow?

Redefining Bradykinesia.

The effect of repetitive transcranial magnetic stimulation on kinesthetic perception, when applied to the somatosensory cortex, was examined. Further, the facilitatory and inhibitory effects of repetitive transcranial magnetic stimulation using different stimulation frequencies were tested. Six female (M age = 32.0 years, SD = 6.7) and nine male (M age = 32.9 years, SD = 6.6) participants were asked to perceive the tendon vibration illusion of the left wrist joint and to replicate the illusion with their right hand. When comparing changes in the corresponding movement amplitude and velocity after three different repetitive transcranial magnetic stimulation protocols (sham, 1 Hz inhibitory, and 5 Hz facilitatory repetitive transcranial magnetic stimulation), the movement amplitude was found to decrease with the inhibitory repetitive transcranial magnetic stimulation, while the movement velocity respectively increased and decreased with the facilitatory and inhibitory repetitive transcranial magnetic stimulation. These results confirmed the modulating effects of repetitive transcranial magnetic stimulation on kinesthetic perception in a single experimental paradigm.