Looming Stimuli Research Articles

Secondary eyes mediate the response to looming objects in jumping spiders ( Phidippus audax , Salticidae)

Some species have sensory systems divided into subsystems with morphologically different sense organs that acquire different types of information within the same modality. Jumping spiders (family Salticidae) have eight eyes. Four eyes are directed anteriorly to view objects in front of the spider: a pair of principal eyes track targets with their movable retinae, while the immobile anterior lateral (AL) eyes have a larger field of view and lower resolution. To test whether the principal eyes, the AL eyes, or both together mediate the response to looming stimuli, we presented spiders with a video of a solid black circle that rapidly expanded (loomed) or contracted (receded). Control spiders and spiders with their principal eyes masked were significantly more likely to back away from the looming stimulus than were spiders with their AL eyes masked. Almost no individuals backed away from the receding stimulus. Our results show that the AL eyes alone mediate the loom response to objects anterior to the spider.

Mapping multisensory parietal face and body areas in humans

Detection and avoidance of impending obstacles is crucial to preventing head and body injuries in daily life. To safely avoid obstacles, locations of objects approaching the body surface are usually detected via the visual system and then used by the motor system to guide defensive movements. Mediating between visual input and motor output, the posterior parietal cortex plays an important role in integrating multisensory information in peripersonal space. We used functional MRI to map parietal areas that see and feel multisensory stimuli near or on the face and body. Tactile experiments using full-body air-puff stimulation suits revealed somatotopic areas of the face and multiple body parts forming a higher-level homunculus in the superior posterior parietal cortex. Visual experiments using wide-field looming stimuli revealed retinotopic maps that overlap with the parietal face and body areas in the postcentral sulcus at the most anterior border of the dorsal visual pathway. Starting at the parietal face area and moving medially and posteriorly into the lower-body areas, the median of visual polar-angle representations in these somatotopic areas gradually shifts from near the horizontal meridian into the lower visual field. These results suggest the parietal face and body areas fuse multisensory information in peripersonal space to guard an individual from head to toe.

Threat modulates perception of looming visual stimuli

Among the most critical of visual functions is the detection of potentially hazardous or threatening aspects of the environment. For example, objects on a collision course with an observer must be quickly identified to allow sufficient time to prepare appropriate defensive or avoidant responses. Directly approaching objects produce a specific accelerating pattern of optical expansion, known as 'looming, which in theory exactly specifies time-to-collision independent of object size or distance. Such looming stimuli have been shown to trigger stereotyped defensive responses in both monkeys [1] and human infants [2]. Psychophysical results in adult participants have similarly suggested sensitivity to looming at early stages of visual processing [3]. Such findings indicate specialization of the visual system to detect and react to such 'looming' stimuli, and have contributed to the traditional view of looming as a purely optical cue to imminent collision [1]. Here, we investigated whether the semantic content of a looming visual stimulus affects perceived time-to-collision by manipulating its threat value. We show that time-to-collision is underestimated for threatening (snakes and spiders) compared to non-threatening (butterflies and rabbits) stimuli. Further, the magnitude of this effect is correlated with self-reported fear. Our results demonstrate affective modulation of the perception of looming stimuli, and suggest that emotion shapes basic aspects of visual perception.

Neural basis of multisensory looming signals

Approaching or looming signals are often related to extremely relevant environmental events (e.g. threats or collisions) making these signals critical for survival. However, the neural network underlying multisensory looming processing is not yet fully understood. Using functional magnetic resonance imaging (fMRI) we identified the neural correlates of audiovisual looming processing in humans: audiovisual looming (vs. receding) signals enhance fMRI-responses in low-level visual and auditory areas plus multisensory cortex (superior temporal sulcus; plus parietal and frontal structures). When characterizing the fMRI-response profiles for multisensory looming stimuli, we found significant enhancements relative to the mean and maximum of unisensory responses in looming-sensitive visual and auditory cortex plus STS. Superadditive enhancements were observed in visual cortex. Subject-specific region-of-interest analyses further revealed superadditive response profiles within all sensory-specific looming-sensitive structures plus bilateral STS for audiovisual looming vs. summed unisensory looming conditions. Finally, we observed enhanced connectivity of bilateral STS with low-level visual areas in the context of looming processing. This enhanced coupling of STS with unisensory regions might potentially serve to enhance the salience of unisensory stimulus features and is accompanied by superadditive fMRI-responses. We suggest that this preference in neural signaling for looming stimuli effectively informs animals to avoid potential threats or collisions.

Swarming and pattern formation due to selective attraction and repulsion

We discuss the collective dynamics of self-propelled particles with selective attraction and repulsion interactions. Each particle, or individual, may respond differently to its neighbours depending on the sign of their relative velocity. Thus, it is able to distinguish approaching (coming closer) and retreating (moving away) individuals. This differentiation of the social response is motivated by the response to looming visual stimuli and may be seen as a generalization of the previously proposed escape and pursuit interactions motivated by empirical evidence for cannibalism as a driving force of collective migration in locusts and Mormon crickets. The model can account for different types of behaviour such as pure attraction, pure repulsion or escape and pursuit, depending on the values (signs) of the different response strengths. It provides, in the light of recent experimental results, an interesting alternative to previously proposed models of collective motion with an explicit velocity-alignment interaction. We discuss the derivation of a coarse-grained description of the system dynamics, which allows us to derive analytically the necessary condition for emergence of collective motion. Furthermore, we analyse systematically the onset of collective motion and clustering in numerical simulations of the model for varying interaction strengths. We show that collective motion arises only in a subregion of the parameter space, which is consistent with the analytical prediction and corresponds to an effective escape and/or pursuit response.

20 Hz membrane potential oscillations are driven by synaptic inputs in collision-detecting neurons in the frog optic tectum

Although the firing patterns of collision-detecting neurons have been described in detail in several species, the mechanisms generating responses in these neurons to visual objects on a collision course remain largely unknown. This is partly due to the limited number of intracellular recordings from such neurons, particularly in vertebrate species. By employing patch recordings in a novel integrated frog eye-tectum preparation we tested the hypothesis that OFF retinal ganglion cells were driving the responses to visual objects on a collision course in the frog optic tectum neurons. We found that the majority (22/26) of neurons in layer 6 responding to visual stimuli fitted the definition of η class collision-detectors: they readily responded to a looming stimulus imitating collision but not a receding stimulus (spike count difference ∼10 times) and the spike firing rate peaked after the stimulus visual angle reached a threshold value of ∼20–45°. In the majority of these neurons (15/22) a slow frequency oscillation (f=∼20Hz) of the neuronal membrane potential could be detected in the responses to a simulated collision stimulus, as well as to turning off the lights. Since OFF retinal ganglion cells could produce such oscillations, our observations are in agreement with the hypothesis that ‘collision’ responses in the frog optic tectum neurons are driven by synaptic inputs from OFF retinal ganglion cells.

Contextual influences of dimension, speed, and direction of motion on subjective time perception

Research has indicated that the direction of motion and the speed of motion can influence the subjective estimates of temporal duration of two-dimensional (2-D) stimuli expanding and contracting within the picture plane. In this study, we investigated whether the contextual cues of stimulus/movement-plane dimensionality (2-D stimuli with implied movement in the picture plane or depth-rendered "3-D" stimuli with implied movement in the depth plane) influence and interact with speed and implied movement direction during interval estimation. Participants viewed a series of standard stimulus durations followed by a test stimulus duration and determined whether the test and standard durations differed. The results indicated that moving stimuli were overestimated relative to stationary stimuli, regardless of the direction of motion or dimensionality. Also, faster-moving stimuli were overestimated relative to slower-moving stimuli. Importantly, an interaction between movement direction and dimensional cues indicated that the loom/recede distinction occurs for 2-D but not for 3-D stimuli. It is possible that the loom/recede distinction for the 2-D condition may be an artifact arising from reduced or from a lack of perceived motion in 2-D "recede" conditions, rather than a specific overestimation for looming stimuli.

Force Measurements on Locusts during Visually-Evoked Collision Avoidance Maneuvers

The collision avoidance behavior of the locust, Schistocerca americana, in response to simulated approaching objects, also called looming stimuli, was investigated in a low speed wind tunnel. The animals were mounted using a sting on a sensitive six-component microbalance custom-designed for the experiments. Forces and moments were measured as a function of time during the simulated approach and interpreted in the context of collision avoidance behaviors. The stimuli presented from the side effectively evoked robust and discernible collision avoidance responses. Locusts attempted to avoid collision by either flying over or under the looming object, or alternatively by steering around it. These efforts appeared in the form of changes in aerodynamic forces and moments as a function of time. It was also observed that the locusts increased the wing flapping frequency in response to the stimulus.

The subjective duration of audiovisual looming and receding stimuli

Looming visual stimuli (log-increasing in proximal size over time) and auditory stimuli (of increasing sound intensity over time) have been shown to be perceived as longer than receding visual and auditory stimuli (i.e., looming stimuli reversed in time). Here, we investigated whether such asymmetry in subjective duration also occurs for audiovisual looming and receding stimuli, as well as for stationary stimuli (i.e., stimuli that do not change in size and/or intensity over time). Our results showed a great temporal asymmetry in audition but a null asymmetry in vision. In contrast, the asymmetry in audiovision was moderate, suggesting that multisensory percepts arise from the integration of unimodal percepts in a maximum-likelihood fashion.

Solitary and Gregarious Locusts Differ in Circadian Rhythmicity of a Visual Output Neuron

Locusts demonstrate remarkable phenotypic plasticity driven by changes in population density. This density dependent phase polyphenism is associated with many physiological, behavioral, and morphological changes, including observations that cryptic solitarious (solitary-reared) individuals start to fly at dusk, whereas gregarious (crowd-reared) individuals are day-active. We have recorded for 24-36 h, from an identified visual output neuron, the descending contralateral movement detector (DCMD) of Schistocerca gregaria in solitarious and gregarious animals. DCMD signals impending collision and participates in flight avoidance maneuvers. The strength of DCMD's response to looming stimuli, characterized by the number of evoked spikes and peak firing rate, varies approximately sinusoidally with a period close to 24 h under constant light in solitarious locusts. In gregarious individuals the 24-h pattern is more complex, being modified by secondary ultradian rhythms. DCMD's strongest responses occur around expected dusk in solitarious locusts but up to 6 h earlier in gregarious locusts, matching the times of day at which locusts of each type are most active. We thus demonstrate a neuronal correlate of a temporal shift in behavior that is observed in gregarious locusts. Our ability to alter the nature of a circadian rhythm by manipulating the rearing density of locusts under identical light-dark cycles may provide important tools to investigate further the mechanisms underlying diurnal rhythmicity.

Neural Responses to Looming Objects in the Dragonfly

Dragonflies have high visual acuity, which, when combined with a remarkably fast visual response, allows them to hunt with a high success rate. They do so by intercepting small flies in flight rather than by chasing from behind. Eight bilateral pairs of large Target‐ Selective Descending Neurons (TSDNs) of the dragonfly ventral nerve cord respond to small, contrasting objects, which presumably represent potential prey. These interneurons are part of the neuronal circuitry that triggers small changes in wing angle and position to control flight during prey interception. In flight, dragonflies extend their legs to catch the prey about 20 ms before contact. The current research investigates the role of the TSDNs in prey contact. Spiking traces from the nerve cord were recorded during the presentation of growing black circles projected on a screen, which simulate approaching the prey. Several loom sizes and speeds were used to cover a range of realistic and unrealistic rates of expansion. We investigated whether the interneurons predict the time to contact of the simulated looming stimuli. We hypothesize that TSDNs innervate circuitry that controls leg muscles for the purpose of catching prey in flight.

An alternative theoretical approach to escape decision-making: the role of visual cues.

Escape enables prey to avoid an approaching predator. The escape decision-making process has traditionally been interpreted using theoretical models that consider ultimate explanations based on the cost/benefit paradigm. Ultimate approaches, however, suffer from inseparable extra-assumptions due to an inability to accurately parameterize the model's variables and their interactive relationships. In this study, we propose a mathematical model that uses intensity of predator-mediated visual stimuli as a basic cue for the escape response. We consider looming stimuli (i.e. expanding retinal image of the moving predator) as a cue to flight initiation distance (FID; distance at which escape begins) of incubating Mallards (Anas platyrhynchos). We then examine the relationship between FID, vegetation cover and directness of predator trajectory, and fit the resultant model to experimental data. As predicted by the model, vegetation concealment and directness of predator trajectory interact, with FID decreasing with increased concealment during a direct approach toward prey, but not during a tangential approach. Thus, we show that a simple proximate expectation, which involves only visual processing of a moving predator, may explain interactive effects of environmental and predator-induced variables on an escape response. We assume that our proximate approach, which offers a plausible and parsimonious explanation for variation in FID, may serve as an evolutionary background for traditional, ultimate explanations and should be incorporated into interpretation of escape behavior.

Reduced looming sensitivity in primary school children with Developmental Co‐ordination Disorder

Almost all locomotor animals are sensitive to optical expansion (visual looming) and for most animals this sensitivity is evident very early in their development. In humans there is evidence that responses to looming stimuli begin in the first 6 weeks of life, but here we demonstrate that as children become independent their perceptual acuity needs to be 50 to 100 times better than has been demonstrated in infants in order to be skilful at collision avoidance at a roadside. We have recently established that sensitivity to the detection of visual looming in 6- to 11-year-old children is significantly below that of adults (Wann, Poulter & Purcell, 2011). Here, using comparable methods, we explore looming detection sensitivity in children with Developmental Co-ordination Disorder (DCD), who show broad patterns of impairment in visuo-motor control. We presented visual simulations of approaching vehicles, scaled to represent different approach rates, to children with DCD aged between 6 and 11 years (n = 11) and typically developing age and gender matched controls (n = 11). Looming detection thresholds were measured under foveal and perifoveal viewing conditions, for isotropic expansion and isotropic expansion with simulated viewpoint motion. Our results show that there are situations in which children with DCD may fail to detect vehicles approaching at speeds in excess of 22 km/h, suggesting a developmental immaturity in looming sensitivity. This provides one of the first clear demonstrations of low-level motion processing deficits in children with DCD. The decrement observed may give rise to potential errors in the road crossing behaviour of these children, whereby approaching vehicles could be perceived as stationary. These findings further contribute towards understanding the adverse statistic that children under 9 years of age are four times more likely than adults to be involved in a road accident as a pedestrian.

The role of the Giant Fibers in visually evoked escape behavior

Event Abstract Back to Event The role of the Giant Fibers in visually evoked escape behavior Catherine R. Von Reyn1 and Gwyneth Card1* 1 Janelia Farm Research Campus, HHMI, United States Escape behaviors are often associated with specialized large-axon command neurons (giant fibers, GFs) that trigger a fast, hard-wired motor program. Although the motor consequences of activating command neurons has been studied in some detail, it still remains unclear how command neurons and their associated circuits function in a natural context during an actual predation attempt. For example, the fruit fly, Drosophila melanogaster, has a pair of bilaterally descending GFs that serve as command neurons for a rapid escape takeoff jump. Wild-type flies takeoff in response to visual looming stimuli that mimic an approaching predator, however as yet no GF responses to looming stimuli have been observed, leading others to postulate that the GFs are not involved in these types of predation response. To address this question we developed a restrained preparation in which we could simultaneously record intracellular Drosophila GF responses to predator-like looming stimuli (see Yee et al. abstract, this conference) while monitoring the fly’s escape jump behavior. Tethered Drosophila respond to looming stimuli with a rapid mesothoracic leg extension (jump) followed by flight, though at a lower rate than in unrestrained flies. In nearly all trials, the GF depolarized in response to looming stimuli, but only in some trials did it elicit an action potential. However, there was a 1:1 correspondence between trials in which the GF fired an action potential and trials in which the fly jumped, and the GF spike consistently preceded the jump with the expected short-latency of the GF pathway. This suggests the GF is involved in the behavioral escape from natural looming stimuli. In some trials where the GF did not fire an action potential the fly still occasionally initiated flight, without any preceding jump, suggesting there is also involvement of an alternate pathway. Taking advantage of the Drosophila genetic toolkit, we anatomically identified candidates for the upstream visual inputs to the GFs that mediate the GFs looming sensitivity. LC4 neurons, which arborize in the output region of the ipsilateral optic lobe, are homologous to Col A neurons known to dye-couple with GFs in larger fly species and thus likely candidates to be presynaptic visual inputs. Synaptotagmin expressing axon terminals of LC4 neurons overlapped with GF dendrites, highly suggestive of a pre-postsynaptic interaction. These data provide evidence that both the GFs and an alternate pathway can participate in a fly’s natural response to an approaching predator by extracting visual information to generate an accurately timed jump and flight, the crucial components of escape behavior. Keywords: Drosophila, Electrophysiology, Escape, flight, Giant Fiber, loom, takeoff, Vision Conference: Tenth International Congress of Neuroethology, College Park. Maryland USA, United States, 5 Aug - 10 Aug, 2012. Presentation Type: Poster (but consider for student poster award) Topic: Sensorimotor Integration Citation: Von Reyn CR and Card G (2012). The role of the Giant Fibers in visually evoked escape behavior. Conference Abstract: Tenth International Congress of Neuroethology. doi: 10.3389/conf.fnbeh.2012.27.00286 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: 03 May 2012; Published Online: 07 Jul 2012. * Correspondence: Dr. Gwyneth Card, Janelia Farm Research Campus, HHMI, Ashburn, VA, 20147, United States, cardg@janelia.hhmi.org 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 Catherine R Von Reyn Gwyneth Card Google Catherine R Von Reyn Gwyneth Card Google Scholar Catherine R Von Reyn Gwyneth Card PubMed Catherine R Von Reyn Gwyneth Card 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.

Visuo-motor transformations involved in the escape response to looming stimuli in the crab Neohelice (=Chasmagnathus) granulata

Escape responses to directly approaching predators represent one instance of an animal's ability to avoid collision. Usually, such responses can be easily evoked in the laboratory using two-dimensional computer simulations of approaching objects, known as looming stimuli. Therefore, escape behaviors are considered useful models for the study of computations performed by the brain to efficiently transform visual information into organized motor patterns. The escape response of the crab Neohelice (previously Chasmagnathus) granulata offers an opportunity to investigate the processing of looming stimuli and its transformation into complex motor patterns. Here we studied the escape performance of this crab to a variety of different looming stimuli. The response always consisted of a vigorous run away from the stimulus. However, the moment at which it was initiated, as well as the developed speed, closely matched the expansion dynamics of each particular stimulus. Thus, we analyzed the response events as a function of several variables that could theoretically be used by the crab (angular size, angular velocity, etc.). Our main findings were that: (1) the decision to initiate the escape run is made when the stimulus angular size increases by 7 deg; (2) the escape run is not a ballistic kind of response, as its speed is adjusted concurrently with changes in the optical stimulus variables; and (3) the speed of the escape run can be faithfully described by a phenomenological input-output relationship based on the stimulus angular increment and the angular velocity of the stimulus.

The velocity of objects traveling along compound trajectories affects firing properties of an identified locust motion-sensitive interneuron

Event Abstract Back to Event The velocity of objects traveling along compound trajectories affects firing properties of an identified locust motion-sensitive interneuron Jack Gray1* and Paul Dick1 1 University of Saskatchewan, Biology, Canada The descending contralateral movement detector (DCMD) is a neuron in the locust visual system that is implicated in controlling escape behavior and is known to encode a ratio of the size and velocity of an object approaching along a single, collision trajectory. Recent studies suggest that the DCMD is also capable of encoding more complex visual information resulting from objects that transition to or from looming trajectories. However, the putative effects of object velocity have not yet been tested for these compound trajectories. We presented locusts with objects moving at different velocities along trajectories that transition to looming within different regions of the locust’s visual field. Concomitant extracellular DCMD recordings were analyzed to determine if firing rate modulation was correlated with disc expansion properties that reflect transition time and location. Transient translating to looming stimuli evoked two local maxima in firing rate- an early, broad and low peak that was followed by a decrease in firing rate associated with the time of transition between translating and looming, increasing in to a higher, primary peak just before the projected time of collision. The characteristics of the primary peak are consistent with the previously reported response of the DCMD to a looming visual stimulus; the timing of the peak was closer to the time of collision and the peak was narrower for higher velocity objects. Novel results show a correlation between the timing of the temporary decrease in firing rate and the time of transition for high velocity objects, but not for lower velocities. In addition, the difference between the height of the early peak and the depth of the following valley was less for objects travelling at higher velocities. These results, among others, may indicate that the DCMD is able to encode more visual information than previously though. In particular, this seems to be the case for objects moving at higher velocities, which would require a more immediate behavioural response in the natural environment of a flying locust. Keywords: insect, Locust, motion detection, Vision Conference: Tenth International Congress of Neuroethology, College Park. Maryland USA, United States, 5 Aug - 10 Aug, 2012. Presentation Type: Poster Presentation (see alternatives below as well) Topic: Sensory: Vision Citation: Gray J and Dick P (2012). The velocity of objects traveling along compound trajectories affects firing properties of an identified locust motion-sensitive interneuron. Conference Abstract: Tenth International Congress of Neuroethology. doi: 10.3389/conf.fnbeh.2012.27.00353 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: 30 Apr 2012; Published Online: 07 Jul 2012. * Correspondence: Dr. Jack Gray, University of Saskatchewan, Biology, Saskatoon, Canada, jack.gray@usask.ca 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 Jack Gray Paul Dick Google Jack Gray Paul Dick Google Scholar Jack Gray Paul Dick PubMed Jack Gray Paul Dick 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.

Threat modulates perception of looming visual stimuli

Objects on a collision course with an observer produce a specific pattern of optical expansion on the retina known as looming, which in theory exactly specifies time-to-collision. Looming stimuli produce stereotyped defensive responses in monkeys and human infants, indicating that the primate visual system is intrinsically tuned to interpret this stimulus as threatening. We investigated how emotional reactions to the semantic content of a looming stimulus affects perceived time-to-collision. We presented either threatening (snakes, spiders) or non-threatening (butterflies and rabbits) stimuli which expanded in size at a rate indicating one of five different times to contact (3.0, 3.5, 4.0, 4.5 or 5.0 s). After 1 s, the image disappeared and participants judged when it would have made contact with them continuing on the same trajectory. Consistent with previous findings, time-to-collision judgments systematically underestimated true arrival time. More importantly, our results showed that the magnitude of this underestimating significantly increased for threatening, compared to non-threatening, stimuli. Further, the magnitude of this increase was correlated with participants’ self-reported fear of snakes and spiders. Traditionally, looming has been interpreted as a purely optical cue to collision. Against that view, our results demonstrate that the semantic content of visual stimuli modulates perceived time-to-contact. Our results suggest that perceived threat led participants to use a larger margin of safety: underestimating time-to-collision errs on the side of allowing more time to prepare defensive responses (or flee). More generally, these results demonstrate that emotion has widespread effects on even very basic aspects of perception.

Role of a collision-sensitive neuron during collision avoidance in flight

Event Abstract Back to Event Role of a collision-sensitive neuron during collision avoidance in flight Raymond W. Chan1*, Fabrizio Gabbiani1, 2 and Reid Harrison3 1 Baylor College of Medicine, United States 2 Rice University, United States 3 Intan Technologies, LLC, United States The neural mechanisms underlying collision avoidance in flight are largely unknown territory. Using a custom designed telemetry chip we record from the DCMD (Descending Contralateral Movement Detector), a collision detecting neuron, and flight muscles of a locust (Schistocerca americana) flying in a wind tunnel. Simultaneously, two high-speed video cameras are used to record flight data of the locust while it performs collision avoidance manoeuvres in response to the simulated approach of an object on a collision course with the animal (i.e., a looming stimulus). Using custom built software, we reconstruct in 3D flight parameters like body orientation and wing height from the stereoscopic videos. Neural data is then correlated with behavioural data to shed light on the neural basis of this behaviour. In addition, we design a filter-based system using the muscle and neural signals to control a virtual drone. Figure 1 Keywords: collision avoidance, DCMD, flight, grasshopper, Locust, Robotics, Wireless Neural Recording Conference: Tenth International Congress of Neuroethology, College Park. Maryland USA, United States, 5 Aug - 10 Aug, 2012. Presentation Type: Poster (but consider for student poster award) Topic: Sensory: Vision Citation: Chan RW, Gabbiani F and Harrison R (2012). Role of a collision-sensitive neuron during collision avoidance in flight. Conference Abstract: Tenth International Congress of Neuroethology. doi: 10.3389/conf.fnbeh.2012.27.00119 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: 25 Apr 2012; Published Online: 07 Jul 2012. * Correspondence: Dr. Raymond W Chan, Baylor College of Medicine, Houston, United States, rchan@cns.bcm.edu 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 Raymond W Chan Fabrizio Gabbiani Reid Harrison Google Raymond W Chan Fabrizio Gabbiani Reid Harrison Google Scholar Raymond W Chan Fabrizio Gabbiani Reid Harrison PubMed Raymond W Chan Fabrizio Gabbiani Reid Harrison 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.

Bursting Neurons and Ultrasound Avoidance in Crickets

Decision making in invertebrates often relies on simple neural circuits composed of only a few identified neurons. The relative simplicity of these circuits makes it possible to identify the key computation and neural properties underlying decisions. In this review, we summarize recent research on the neural basis of ultrasound avoidance in crickets, a response that allows escape from echolocating bats. The key neural property shaping behavioral output is high-frequency bursting of an identified interneuron, AN2, which carries information about ultrasound stimuli from receptor neurons to the brain. AN2’s spike train consists of clusters of spikes – bursts – that may be interspersed with isolated, non-burst spikes. AN2 firing is necessary and sufficient to trigger avoidance steering but only high-rate firing, such as occurs in bursts, evokes this response. AN2 bursts are therefore at the core of the computation involved in deciding whether or not to steer away from ultrasound. Bursts in AN2 are triggered by synaptic input from nearly synchronous bursts in ultrasound receptors. Thus the population response at the very first stage of sensory processing – the auditory receptor – already differentiates the features of the stimulus that will trigger a behavioral response from those that will not. Adaptation, both intrinsic to AN2 and within ultrasound receptors, scales the burst-generating features according to the stimulus statistics, thus filtering out background noise and ensuring that bursts occur selectively in response to salient peaks in ultrasound intensity. Furthermore AN2’s sensitivity to ultrasound varies adaptively with predation pressure, through both developmental and evolutionary mechanisms. We discuss how this key relationship between bursting and the triggering of avoidance behavior is also observed in other invertebrate systems such as the avoidance of looming visual stimuli in locusts or heat avoidance in beetles.

Responses of central-complex neurons of the locust to looming stimuli

Responses of central-complex neurons of the locust to looming stimuli