scholarly journals The effect of optic flow cues on honeybee flight control in wind

2021 ◽  
Vol 288 (1943) ◽  
pp. 20203051
Author(s):  
Emily Baird ◽  
Norbert Boeddeker ◽  
Mandyam V. Srinivasan
Keyword(s):  
Flight Control ◽  
Optic Flow ◽  
Visual Motion ◽  
Transverse Component ◽  
Natural Environments ◽  
Ground Speed ◽  
Simple Strategy ◽  
Longitudinal Optic ◽  
Transverse Optic ◽  
Robust Systems

To minimize the risk of colliding with the ground or other obstacles, flying animals need to control both their ground speed and ground height. This task is particularly challenging in wind, where head winds require an animal to increase its airspeed to maintain a constant ground speed and tail winds may generate negative airspeeds, rendering flight more difficult to control. In this study, we investigate how head and tail winds affect flight control in the honeybee Apis mellifera , which is known to rely on the pattern of visual motion generated across the eye—known as optic flow—to maintain constant ground speeds and heights. We find that, when provided with both longitudinal and transverse optic flow cues (in or perpendicular to the direction of flight, respectively), honeybees maintain a constant ground speed but fly lower in head winds and higher in tail winds, a response that is also observed when longitudinal optic flow cues are minimized. When the transverse component of optic flow is minimized, or when all optic flow cues are minimized, the effect of wind on ground height is abolished. We propose that the regular sidewards oscillations that the bees make as they fly may be used to extract information about the distance to the ground, independently of the longitudinal optic flow that they use for ground speed control. This computationally simple strategy could have potential uses in the development of lightweight and robust systems for guiding autonomous flying vehicles in natural environments.

scholarly journals The influence of visual landscape on the free flight behavior of the fruit fly Drosophila melanogaster

2002 ◽  
Vol 205 (3) ◽  
pp. 327-343 ◽  
Author(s):  
Lance F. Tammero ◽  
Michael H. Dickinson
Keyword(s):  
Drosophila Melanogaster ◽  
Flight Control ◽  
Optic Flow ◽  
Visual Motion ◽  
Fruit Fly ◽  
Flight Behavior ◽  
Large Field ◽  
Visual Environment ◽  
Free Flight ◽  
Visual Contrast

SUMMARY To study the visual cues that control steering behavior in the fruit fly Drosophila melanogaster, we reconstructed three-dimensional trajectories from images taken by stereo infrared video cameras during free flight within structured visual landscapes. Flies move through their environment using a series of straight flight segments separated by rapid turns, termed saccades, during which the fly alters course by approximately 90° in less than 100 ms. Altering the amount of background visual contrast caused significant changes in the fly’s translational velocity and saccade frequency. Between saccades, asymmetries in the estimates of optic flow induce gradual turns away from the side experiencing a greater motion stimulus, a behavior opposite to that predicted by a flight control model based upon optomotor equilibrium. To determine which features of visual motion trigger saccades, we reconstructed the visual environment from the fly’s perspective for each position in the flight trajectory. From these reconstructions, we modeled the fly’s estimation of optic flow on the basis of a two-dimensional array of Hassenstein–Reichardt elementary motion detectors and, through spatial summation, the large-field motion stimuli experienced by the fly during the course of its flight. Event-triggered averages of the large-field motion preceding each saccade suggest that image expansion is the signal that triggers each saccade. The asymmetry in output of the local motion detector array prior to each saccade influences the direction (left versus right) but not the magnitude of the rapid turn. Once initiated, visual feedback does not appear to influence saccade kinematics further. The total expansion experienced before a saccade was similar for flight within both uniform and visually textured backgrounds. In summary, our data suggest that complex behavioral patterns seen during free flight emerge from interactions between the flight control system and the visual environment.

Children’s perceptual sensitivity to optic flow-like visual motion differs from adults.

2021 ◽  
Vol 57 (11) ◽  
pp. 1810-1821
Author(s):  
Yiming Qian ◽  
Andrea R. Seisler ◽  
Rick O. Gilmore
Keyword(s):  
Optic Flow ◽  
Visual Motion ◽  
Perceptual Sensitivity

scholarly journals Strong Coupling of Folded Phonons with Plasmons in 6H-SiC Micro/Nanocrystals

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2296 ◽  
Author(s):  
Yao Huang ◽  
Run Yang ◽  
Shijie Xiong ◽  
Jian Chen ◽  
Xinglong Wu
Keyword(s):  
Silicon Carbide ◽  
Electrical Properties ◽  
Raman Scattering ◽  
Film Thickness ◽  
Strong Coupling ◽  
Energy Gaps ◽  
Longitudinal Optic ◽  
Transverse Optic

Silicon carbide (SiC) has a large number of polytypes of which 3C-, 4H-, 6H-SiC are most common. Since different polytypes have different energy gaps and electrical properties, it is important to identify and characterize various SiC polytypes. Here, Raman scattering is performed on 6H-SiC micro/nanocrystal (MNC) films to investigate all four folded transverse optic (TO) and longitudinal optic (LO) modes. With increasing film thickness, the four folded TO modes exhibit the same frequency downshift, whereas the four folded LO modes show a gradually-reduced downshift. For the same film thickness, all the folded modes show larger frequency downshifts with decreasing MNC size. Based on plasmons on MNCs, these folded modes can be attributed to strong coupling of the folded phonons with plasmons which show different strengths for the different folded modes while changing the film thickness and MNC size. This work provides a useful technique to identify SiC polytypes from Raman scattering.

scholarly journals Neural selectivity for visual motion in macaque area V3A

2020 ◽  
Author(s):  
Nardin Nakhla ◽  
Yavar Korkian ◽  
Matthew R. Krause ◽  
Christopher C. Pack
Keyword(s):  
Visual Cortex ◽  
Optic Flow ◽  
Functional Role ◽  
Visual Motion ◽  
Flow Patterns ◽  
Brain Regions ◽  
Direction Selectivity ◽  
Motion Processing ◽  
Imaging Studies ◽  
Motion Direction

AbstractThe processing of visual motion is carried out by dedicated pathways in the primate brain. These pathways originate with populations of direction-selective neurons in the primary visual cortex, which project to dorsal structures like the middle temporal (MT) and medial superior temporal (MST) areas. Anatomical and imaging studies have suggested that area V3A might also be specialized for motion processing, but there have been very few studies of single-neuron direction selectivity in this area. We have therefore performed electrophysiological recordings from V3A neurons in two macaque monkeys (one male and one female) and measured responses to a large battery of motion stimuli that includes translation motion, as well as more complex optic flow patterns. For comparison, we simultaneously recorded the responses of MT neurons to the same stimuli. Surprisingly, we find that overall levels of direction selectivity are similar in V3A and MT and moreover that the population of V3A neurons exhibits somewhat greater selectivity for optic flow patterns. These results suggest that V3A should be considered as part of the motion processing machinery of the visual cortex, in both human and non-human primates.Significance statementAlthough area V3A is frequently the target of anatomy and imaging studies, little is known about its functional role in processing visual stimuli. Its contribution to motion processing has been particularly unclear, with different studies yielding different conclusions. We report a detailed study of direction selectivity in V3A. Our results show that single V3A neurons are, on average, as capable of representing motion direction as are neurons in well-known structures like MT. Moreover, we identify a possible specialization for V3A neurons in representing complex optic flow, which has previously been thought to emerge in higher-order brain regions. Thus it appears that V3A is well-suited to a functional role in motion processing.

scholarly journals Optic Flow: A History

i-Perception ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 204166952110557
Author(s):  
Diederick C. Niehorster
Keyword(s):  
Optic Flow ◽  
Visual Motion ◽  
Scientific Literature ◽  
Archival Research ◽  
Visual World ◽  
Global Pattern ◽  
Self Motion

The concept of optic flow, a global pattern of visual motion that is both caused by and signals self-motion, is canonically ascribed to James Gibson's 1950 book “ The Perception of the Visual World.” There have, however, been several other developments of this concept, chiefly by Gwilym Grindley and Edward Calvert. Based on rarely referenced scientific literature and archival research, this article describes the development of the concept of optic flow by the aforementioned authors and several others. The article furthermore presents the available evidence for interactions between these authors, focusing on whether parts of Gibson's proposal were derived from the work of Grindley or Calvert. While Grindley's work may have made Gibson aware of the geometrical facts of optic flow, Gibson's work is not derivative of Grindley's. It is furthermore shown that Gibson only learned of Calvert's work in 1956, almost a decade after Gibson first published his proposal. In conclusion, the development of the concept of optic flow presents an intriguing example of convergent thought in the progress of science.

TO-LO Splitting in Infrared Spectra of Thin Films

1996 ◽  
Vol 50 (6) ◽  
pp. 759-763 ◽  
Author(s):  
Kiyoshi Yamamoto ◽  
Akio Masui
Keyword(s):  
Thin Films ◽  
Infrared Spectra ◽  
Molecular Orientation ◽  
Peak Position ◽  
Peak Shape ◽  
Surface Phenomena ◽  
Longitudinal Optic ◽  
Transverse Optic ◽  
Optical Behavior ◽  
Optical Calculation

The importance of transverse optic-longitudinal optic (TO-LO) splitting in the interpretation of infrared spectra of thin films is experimentally presented. When infrared spectra are observed at oblique angles of incidence, the shifts in peak position and/or the changes in peak shape may be due to TO-LO splitting. Before one assigns the optical behavior to surface phenomena such as molecular orientation, proper care must be employed. The proposed technique includes optical calculation to extract surface phenomena from TO-LO splitting in the spectra, and it is applied to reflection absorption spectra of perfluoropolyether.

Central complex neurons exhibit behaviorally gated responses to visual motion in Drosophila

2014 ◽  
Vol 111 (1) ◽  
pp. 62-71 ◽  
Author(s):  
Peter T. Weir ◽  
Bettina Schnell ◽  
Michael H. Dickinson
Keyword(s):  
Optic Flow ◽  
Calcium Imaging ◽  
Visual Motion ◽  
Central Complex ◽  
Direct Measure ◽  
Forward Motion ◽  
Sensory Stimuli ◽  
Whole Cell Patch Clamp ◽  
Baseline Activity ◽  
Tethered Flight

Sensory systems provide abundant information about the environment surrounding an animal, but only a small fraction of that information is relevant for any given task. One example of this requirement for context-dependent filtering of a sensory stream is the role that optic flow plays in guiding locomotion. Flying animals, which do not have access to a direct measure of ground speed, rely on optic flow to regulate their forward velocity. This observation suggests that progressive optic flow, the pattern of front-to-back motion on the retina created by forward motion, should be especially salient to an animal while it is in flight, but less important while it is standing still. We recorded the activity of cells in the central complex of Drosophila melanogaster during quiescence and tethered flight using both calcium imaging and whole cell patch-clamp techniques. We observed a genetically identified set of neurons in the fan-shaped body that are unresponsive to visual motion while the animal is quiescent. During flight their baseline activity increases, and they respond to front-to-back motion with changes relative to this baseline. The results provide an example of how nervous systems selectively respond to complex sensory stimuli depending on the current behavioral state of the animal.

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