scholarly journals Avoiding pitfalls: Trace conditioning and rapid aversive learning during route navigation in desert ants

2019 ◽  
Author(s):  
Antoine Wystrach ◽  
Cornelia Buehlmann ◽  
Sebastian Schwarz ◽  
Ken Cheng ◽  
Paul Graham
Keyword(s):  
Visual Information ◽  
Trace Conditioning ◽  
Neural Circuitry ◽  
Natural Environments ◽  
The Novel ◽  
Visually Guided ◽  
Aversive Learning ◽  
Complex Environments ◽  
Learning And Development ◽  
Goal Direction

AbstractThe ability of bees and ants to learn long visually guided routes in complex environments is perhaps one of the most spectacular pieces of evidence for the impressive power of their small brains. While flying bees can visit flowers in an optimised sequence over kilometres, walking ants can precisely recapitulate routes of up to a hundred metres in complex environments. It is clear that route following depends largely on learnt visual information and we have good idea how views can guide individuals along them, however little is known about the mechanisms that control route learning and development. Here we show that ants in natural environments can actively learn a route detour to avoid a pit trap and that this depends on a process analogous to aversive trace conditioning. Views experienced before falling into the trap become associated with the ensuing negative outcome and thus trigger salutary turns on the subsequent trip. This drives the ants to orient away from the goal direction and avoid the trap. If the pit is avoided, the novel views experienced during the detour become positively reinforced and the new route crystallises. We discuss how such an interplay between appetitive and aversive memories might be implemented in insect neural circuitry.

scholarly journals Insect photoreceptor adaptations to night vision

2017 ◽  
Vol 372 (1717) ◽  
pp. 20160077 ◽  
Author(s):  
Anna Honkanen ◽  
Esa-Ville Immonen ◽  
Iikka Salmela ◽  
Kyösti Heimonen ◽  
Matti Weckström
Keyword(s):  
Visual Information ◽  
Insect Vision ◽  
Night Vision ◽  
Single Photons ◽  
Visually Guided ◽  
Neural Signals ◽  
Light Responses ◽  
Anatomical Structures ◽  
Retinal Photoreceptors ◽  
Physiological Adaptations

Night vision is ultimately about extracting information from a noisy visual input. Several species of nocturnal insects exhibit complex visually guided behaviour in conditions where most animals are practically blind. The compound eyes of nocturnal insects produce strong responses to single photons and process them into meaningful neural signals, which are amplified by specialized neuroanatomical structures. While a lot is known about the light responses and the anatomical structures that promote pooling of responses to increase sensitivity, there is still a dearth of knowledge on the physiology of night vision. Retinal photoreceptors form the first bottleneck for the transfer of visual information. In this review, we cover the basics of what is known about physiological adaptations of insect photoreceptors for low-light vision. We will also discuss major enigmas of some of the functional properties of nocturnal photoreceptors, and describe recent advances in methodologies that may help to solve them and broaden the field of insect vision research to new model animals. This article is part of the themed issue ‘Vision in dim light’.

scholarly journals A Novel Neuronal Pathway for Visually Guided Escape in Drosophila melanogaster

2009 ◽  
Vol 102 (2) ◽  
pp. 875-885 ◽  
Author(s):  
Haleh Fotowat ◽  
Amir Fayyazuddin ◽  
Hugo J. Bellen ◽  
Fabrizio Gabbiani
Keyword(s):  
Drosophila Melanogaster ◽  
Activity Pattern ◽  
Escape Response ◽  
Angular Size ◽  
The Novel ◽  
Visually Guided ◽  
Motor Sequence ◽  
Motor Programs ◽  
Sensory Activity ◽  
Descending Interneurons

Drosophila melanogaster exhibits a robust escape response to objects approaching on a collision course. Although a pair of large command interneurons called the giant fibers (GFs) have been postulated to trigger such behaviors, their role has not been directly demonstrated. Here, we show that escape from visual stimuli like those generated by approaching predators does not rely on the activation of the GFs and consists of a more complex and less stereotyped motor sequence than that evoked by the GFs. Instead, the timing of escape is tightly correlated with the activity of previously undescribed descending interneurons that signal a threshold angular size of the approaching object. The activity pattern of these interneurons shares features with those of visual escape circuits of several species, including pigeons, frogs, and locusts, and may therefore have evolved under similar constraints. These results show that visually evoked escapes in Drosophila can rely on at least two descending neuronal pathways: the GFs and the novel pathway we characterize electrophysiologically. These pathways exhibit very different patterns of sensory activity and are associated with two distinct motor programs.

Levels of modeling of mechanisms of visually guided behavior

1987 ◽  
Vol 10 (3) ◽  
pp. 407-436 ◽  
Author(s):  
Michael A. Arbib
Keyword(s):  
Neural Circuits ◽  
Neural Circuitry ◽  
Learning Approach ◽  
Visually Guided ◽  
Visuomotor Coordination ◽  
Prey Recognition ◽  
High Level ◽  
Organizational Principles ◽  
Different Levels ◽  
Dextrous Hands

AbstractIntermediate constructs are required as bridges between complex behaviors and realistic models of neural circuitry. For cognitive scientists in general, schemas are the appropriate functional units; brain theorists can work with neural layers as units intermediate between structures subserving schemas and small neural circuits.After an account of different levels of analysis, we describe visuomotor coordination in terms of perceptual schemas and motor schemas. The interest of schemas to cognitive science in general is illustrated with the example of perceptual schemas in high-level vision and motor schemas in the control of dextrous hands.Rana computatrix, the computational frog, is introduced to show how one constructs an evolving set of model families to mediate flexible cooperation between theory and experiment. Rana computatrix may be able to do for the study of the organizational principles of neural circuitry what Aplysia has done for the study of subcellular mechanisms of learning. Approach, avoidance, and detour behavior in frogs and toads are analyzed in terms of interacting schemas. Facilitation and prey recognition are implemented as tectal-pretectal interactions, with the tectum modeled by an array of tectal columns. We show how layered neural computation enters into models of stereopsis and how depth schemas may involve the interaction of accommodation and binocular cues in anurans.

scholarly journals A method for single-neuron chronic recording from the retina in awake mice

Science ◽  
2018 ◽  
Vol 360 (6396) ◽  
pp. 1447-1451 ◽  
Author(s):  
Guosong Hong ◽  
Tian-Ming Fu ◽  
Mu Qiao ◽  
Robert D. Viveros ◽  
Xiao Yang ◽  
...  
Keyword(s):  
Retinal Ganglion Cells ◽  
Visual Information ◽  
Single Neuron ◽  
Ganglion Cells ◽  
Ex Vivo ◽  
Neural Circuitry ◽  
Retinal Ganglion ◽  
Chronic Recording ◽  
The Brain

The retina, which processes visual information and sends it to the brain, is an excellent model for studying neural circuitry. It has been probed extensively ex vivo but has been refractory to chronic in vivo electrophysiology. We report a nonsurgical method to achieve chronically stable in vivo recordings from single retinal ganglion cells (RGCs) in awake mice. We developed a noncoaxial intravitreal injection scheme in which injected mesh electronics unrolls inside the eye and conformally coats the highly curved retina without compromising normal eye functions. The method allows 16-channel recordings from multiple types of RGCs with stable responses to visual stimuli for at least 2 weeks, and reveals circadian rhythms in RGC responses over multiple day/night cycles.

Crustacean Visual Circuits Underlying Behavior

2019 ◽  
Author(s):  
Daniel Tomsic ◽  
Julieta Sztarker
Keyword(s):  
Visual Processing ◽  
Visual Information ◽  
General Structure ◽  
Visual Space ◽  
Experimental Manipulation ◽  
Visually Guided ◽  
Decapod Crustaceans ◽  
Behavioral Experiments ◽  
Electrophysiological Recordings ◽  
Visual Behaviors

Decapod crustaceans, in particular semiterrestrial crabs, are highly visual animals that greatly rely on visual information. Their responsiveness to visual moving stimuli, with behavioral displays that can be easily and reliably elicited in the laboratory, together with their sturdiness for experimental manipulation and the accessibility of their nervous system for intracellular electrophysiological recordings in the intact animal, make decapod crustaceans excellent experimental subjects for investigating the neurobiology of visually guided behaviors. Investigations of crustaceans have elucidated the general structure of their eyes and some of their specializations, the anatomical organization of the main brain areas involved in visual processing and their retinotopic mapping of visual space, and the morphology, physiology, and stimulus feature preferences of a number of well-identified classes of neurons, with emphasis on motion-sensitive elements. This anatomical and physiological knowledge, in connection with results of behavioral experiments in the laboratory and the field, are revealing the neural circuits and computations involved in important visual behaviors, as well as the substrate and mechanisms underlying visual memories in decapod crustaceans.

scholarly journals An obstacle disturbance selection framework: emergent robot steady states under repeated collisions

2020 ◽  
Vol 39 (13) ◽  
pp. 1549-1566
Author(s):  
Feifei Qian ◽  
Daniel E Koditschek
Keyword(s):  
Horizontal Plane ◽  
Robot Dynamics ◽  
Natural Environments ◽  
Complex Environments ◽  
Cluttered Environments ◽  
Robot Trajectory ◽  
Aspect Ratios ◽  
The Face ◽  
Selection Framework ◽  
Contact Position

Natural environments are often filled with obstacles and disturbances. Traditional navigation and planning approaches normally depend on finding a traversable “free space” for robots to avoid unexpected contact or collision. We hypothesize that with a better understanding of the robot–obstacle interactions, these collisions and disturbances can be exploited as opportunities to improve robot locomotion in complex environments. In this article, we propose a novel obstacle disturbance selection (ODS) framework with the aim of allowing robots to actively select disturbances to achieve environment-aided locomotion. Using an empirically characterized relationship between leg–obstacle contact position and robot trajectory deviation, we simplify the representation of the obstacle-filled physical environment to a horizontal-plane disturbance force field. We then treat each robot leg as a “disturbance force selector” for prediction of obstacle-modulated robot dynamics. Combining the two representations provides analytical insights into the effects of gaits on legged traversal in cluttered environments. We illustrate the predictive power of the ODS framework by studying the horizontal-plane dynamics of a quadrupedal robot traversing an array of evenly-spaced cylindrical obstacles with both bounding and trotting gaits. Experiments corroborate numerical simulations that reveal the emergence of a stable equilibrium orientation in the face of repeated obstacle disturbances. The ODS reduction yields closed-form analytical predictions of the equilibrium position for different robot body aspect ratios, gait patterns, and obstacle spacings. We conclude with speculative remarks bearing on the prospects for novel ODS-based gait control schemes for shaping robot navigation in perturbation-rich environments.

Vision, Color Vision, and Visually Guided Behavior: The Novel Toxicological Targets of 2,2′,4,4′-Tetrabromodiphenyl Ether (BDE-47)

2017 ◽  
Vol 4 (4) ◽  
pp. 132-136 ◽  
Author(s):  
Ting Xu ◽  
Yuan Liu ◽  
Ruijie Pan ◽  
Bin Zhang ◽  
Daqiang Yin ◽  
...  
Keyword(s):  
Color Vision ◽  
The Novel ◽  
Visually Guided

scholarly journals Humans exploit the biomechanics of bipedal gait during visually guided walking over complex terrain

2013 ◽  
Vol 280 (1762) ◽  
pp. 20130700 ◽  
Author(s):  
Jonathan Samir Matthis ◽  
Brett R. Fajen
Keyword(s):  
Complex Terrain ◽  
Visual Information ◽  
Human Walking ◽  
Energetic Efficiency ◽  
Visually Guided ◽  
Bipedal Gait ◽  
Flat Obstacle

How do humans achieve such remarkable energetic efficiency when walking over complex terrain such as a rocky trail? Recent research in biomechanics suggests that the efficiency of human walking over flat, obstacle-free terrain derives from the ability to exploit the physical dynamics of our bodies. In this study, we investigated whether this principle also applies to visually guided walking over complex terrain. We found that when humans can see the immediate foreground as little as two step lengths ahead, they are able to choose footholds that allow them to exploit their biomechanical structure as efficiently as they can with unlimited visual information. We conclude that when humans walk over complex terrain, they use visual information from two step lengths ahead to choose footholds that allow them to approximate the energetic efficiency of walking in flat, obstacle-free environments.

Visually guided stepping under conditions of step cycle-related denial of visual information

1996 ◽  
Vol 109 (2) ◽  
Author(s):  
M.A. Hollands ◽  
D.E. Marple-Horvat
Keyword(s):  
Visual Information ◽  
Visually Guided ◽  
Step Cycle

scholarly journals Polynucleobacter cosmopolitanus sp. nov., free-living planktonic bacteria inhabiting freshwater lakes and rivers

2010 ◽  
Vol 60 (1) ◽  
pp. 166-173 ◽  
Author(s):  
Martin W. Hahn ◽  
Elke Lang ◽  
Ulrike Brandt ◽  
Heinrich Lünsdorf ◽  
Qinglong L. Wu ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Novel Species ◽  
Sequence Similarity ◽  
Rrna Gene ◽  
Natural Environments ◽  
The Novel ◽  
Free Living ◽  
Monophyletic Cluster ◽  
Freshwater Habitats

Five heterotrophic, aerobic, catalase- and oxidase-positive, non-motile strains were characterized from freshwater habitats located in Austria, France, Uganda, P. R. China and New Zealand. The strains shared 16S rRNA gene similarities of ≥99.3 %. The novel strains grew on NSY medium over a temperature range of 10–35 °C (two strains also grew at 5 °C and one strain grew at 38 °C) and a NaCl tolerance range of 0.0–0.3 % (four strains grew up to 0.5 % NaCl). The predominant fatty acids were C16 : 0, C18 : 1 ω7c, C12 : 0 3-OH, and summed feature 3 (including C16 : 1 ω7c). The DNA G+C content of strain MWH-MoIso2T was 44.9 mol%. Phylogenetic analysis of 16S rRNA gene sequences demonstrated that the five new strains formed a monophyletic cluster closely related to Polynucleobacter necessarius (96–97 % sequence similarity). This cluster also harboured other isolates as well as environmental sequences which have been obtained from several habitats. Investigations with taxon-specific FISH probes demonstrated that the novel bacteria dwell as free-living, planktonic cells in freshwater systems. Based on the revealed phylogeny and pronounced chemotaxonomic differences to P. necessarius (presence of >7 % C12 : 0 3-OH and absence of C12 : 0 and C12 : 0 2-OH), the new strains are suggested to represent a novel species, for which the name Polynucleobacter cosmopolitanus sp. nov. is proposed. The type strain is MWH-MoIso2T (=DSM 21490T=CIP 109840T=LMG 25212T). The novel species belongs to the minority of described species of free-living bacteria for which both in situ data from their natural environments and culture-based knowledge are available.

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