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1. Online Recognition of Bimanual Coordination Provides Important Context for Movement Data in Bimanual Teleoperated Robots

   Boehm, J. ; Fey, N. ; Majewicz Fey, A. ( September 2021 , IEEE International Conference on Robotics and Automation)

   null (Ed.)

   An important problem in designing human-robot systems is the integration of human intent and performance in the robotic control loop, especially in complex tasks. Bimanual coordination is a complex human behavior that is critical in many fine motor tasks, including robot-assisted surgery. To fully leverage the capabilities of the robot as an intelligent and assistive agent, online recognition of bimanual coordination could be important. Robotic assistance for a suturing task, for example, will be fundamentally different during phases when the suture is wrapped around the instrument (i.e., making a c- loop), than when the ends of the suture are pulled apart. In this study, we develop an online recognition method of bimanual coordination modes (i.e., the directions and symmetries of right and left hand movements) using geometric descriptors of hand motion. We (1) develop this framework based on ideal trajectories obtained during virtual 2D bimanual path following tasks performed by human subjects operating Geomagic Touch haptic devices, (2) test the offline recognition accuracy of bi- manual direction and symmetry from human subject movement trials, and (3) evalaute how the framework can be used to characterize 3D trajectories of the da Vinci Surgical System’s surgeon-side manipulators during bimanual surgical training tasks. In the human subject trials, our geometric bimanual movement classification accuracy was 92.3% for movement direction (i.e., hands moving together, parallel, or away) and 86.0% for symmetry (e.g., mirror or point symmetry). We also show that this approach can be used for online classification of different bimanual coordination modes during needle transfer, making a C loop, and suture pulling gestures on the da Vinci system, with results matching the expected modes. Finally, we discuss how these online estimates are sensitive to task environment factors and surgeon expertise, and thus inspire future work that could leverage adaptive control strategies to enhance user skill during robot-assisted surgery. 

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2. The effect of learning on heart rate and behavior of European starlings ( Sturnus vulgaris )

   https://doi.org/10.1002/jez.2319  

   Glassman, Laura W. ; Hagmann Carl E. ; Qadri, Muhammad A. ; Cook, Robert G. ; Romero, L. Michael ( September 2019 , Journal of Experimental Zoology Part A: Ecological and Integrative Physiology)

   Wild‐caught European starlings (Sturnus vulgaris) were exposed to a learning task to determine whether heart rate (HR) and behavior responses to the learning activated the sympathetic nervous system. Birds learned to discriminate between images of opposite convexity (concave and convex) based on shading cues in a closed economy (food only available through task completion). Once learned, the task was changed in three ways: (a) manipulating the angle and shape of the image; (b) altering the availability of the task; and (c) reversing the positive stimulus. HR, used as an index of catecholamine release, was measured during each change to determine whether having to alter previously established behaviors to learn new behaviors elicited a sympathetic response. Starlings decreased their HR during the initial discrimination training and did not alter their HR when presented with modified images or when the positive stimulus was reversed. However, HR increased when the task became unavailable and decreased upon its return, suggesting that preventing task performance was perceived as stressful. Birds also modified their behavior when tasks were changed. The number of trials per minute decreased during the reversal treatment, as did the success rate, suggesting that starlings may try to conserve energy when access to food diminishes. This is also supported by the decrease in perch hops per minute when the task was unavailable and the subsequent increase upon its return. Overall, these results suggest that learning per se does not activate the sympathetic nervous system and, therefore, is not a stressor for wild birds.

    

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3. Density‐dependent within‐patch movement behavior of two competing species

   https://doi.org/10.1002/ece3.10753  

   Cronin, James T. ; Goddard, II, Jerome ; Krivchenia, Aaron ; Shivaji, Ratnasingham ( November 2023 , Ecology and Evolution)

   Movement behavior is central to understanding species distributions, population dynamics and coexistence with other species. Although the relationship between conspecific density and emigration has been well studied, little attention has been paid to how interspecific competitor density affects another species' movement behavior. We conducted releases of two species of competingTriboliumflour beetles at different densities, alone and together in homogeneous microcosms, and tested whether their recaptures‐with‐distance were well described by a random‐diffusion model. We also determined whether mean displacement distances varied with the release density of conspecific and heterospecific beetles. A diffusion model provided a good fit to the redistribution ofT. castaneumandT. confusumat all release densities, explaining an average of >60% of the variation in recaptures. For both species, mean displacement (directly proportional to the diffusion rate) exhibited a humped‐shaped relationship with conspecific density. Finally, we found that both species of beetle impacted the within‐patch movement rates of the other species, but the effect depended on density. ForT. castaneumin the highest density treatment, the addition of equal numbers ofT. castaneumorT. confusumhad the same effect, with mean displacements reduced by approximately one half. The same result occurred forT. confusumreleased at an intermediate density. In both cases, it was total beetle abundance, not species identity that mattered to mean displacement. We suggest that displacement or diffusion rates that exhibit a nonlinear relationship with density or depend on the presence or abundance of interacting species should be considered when attempting to predict the spatial spread of populations or scaling up to heterogeneous landscapes.

    

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4. ­­Effect of multimodal cues from a predatory fish on refuge use and foraging on an amphidromous shrimp

   https://doi.org/10.7717/peerj.11011  

   Ocasio-Torres, Maria E. ; Crowl, Todd A. ; Sabat, Alberto M. ( January 2021 , PeerJ)

   null (Ed.)

   Background Prey can alter their behavior when detecting predator cues. Little is known about which sensory channel, number of channels, or the interaction among channels that shrimp species use to evaluate the threat from predators. The amphidromous shrimp Xiphocaris elongata has an induced defense, an elongated rostrum, where predatory fishes are present. We sought to test if kairomones or visual cues when presented singly from fish either eating flakes or shrimp, had more effect on altering the temporal feeding and refuge use patterns of long-rostrum (LR) X. elongata . We were also interested in elucidating potential interactions among cues when presented simultaneously in different combinations (kairomones + visual + mechanosensory, kairomones + alarm + visual, kairomones + alarm, kairomones + visual) on the same response variables. We expected that when presented alone kairomones will significantly increase refuge use and decrease foraging, particularly late at night, in comparison to visual cues alone, and that multiple cues when presented simultaneously will further increase refuge use and decrease foraging at night. Methods We exposed shrimp to individual or multiple cues from the predatory fish mountain mullet, Augonostomus monticola . We examined shrimp behavior with respect to refuge use and foraging activity during four time periods (after sunset, nighttime, sunrise, and sunset) in a 24-hour period. Results Shrimp presented fish visual and chemical cues singly did not differ from one another but differed from control shrimp (no cues) with respect to refuge use or foraging. The number of shrimp using refuge in the treatment with most cues (KVM: kairomones+ visual + mechanosensory) was higher than in all the treatments with less cues. A significant decline in foraging was observed when multiple cues were presented simultaneously. The highest number of shrimp foraged one hour after sunset and at nighttime. A significant interaction was observed between cue treatments and time periods, with shrimp in the KVM treatment foraging less and using more refuge late at night and at sunrise than shrimp in other treatments or time periods. Conclusions The observation that fish chemical and visual cues when presented singly produced similar refuge use and foraging patterns was contrary to expectation and suggests that visual and chemical cues, when presented alone, provide redundant information to X. elongata with regards to predation threat. The significant increase in refuge use and reduction in foraging observed in the KVM treatment suggest multimodal signal enhancement in the perception of threat. This makes evolutionary sense in “noisy” environments, such as streams, where detection, localization, and intention of predators is much improved when cues are received through multiple sensory channels. 

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5. Shoaling in the Trinidadian guppy: costs, benefits, and plasticity in response to an ambush predator

   https://doi.org/10.1093/beheco/arac038  

   Li, Anna ; Richardson, Jean M. L. ; Helen Rodd, F. ; Briffa, ed., Mark ( May 2022 , Behavioral Ecology)

   Shoaling, the formation of social groupings in fish, can provide benefits including reduced predation risk. However, it can also inflict costs including increased competition for resources, transmission of parasites, and salience to predators. Trinidadian guppies exhibit inter-population variation in shoaling behavior where individuals coexisting with large piscivorous predators (high predation localities) spend most of their time in shoals and those coexisting with an ambush predator, Rivulus hartii (recently, Anablepsoides hartii), that preys primarily on smaller guppies (low predation localities) do not. It has been suggested that this predator selects for reduced shoaling because doing so reduces salience to the predator. Here, as far as we know, we perform the first test of this idea. First, we investigated the effectiveness of shoaling in encounters with this predator. In survival trials, where one rivulus interacted with a group of guppies, we found that the predator was more likely to attack individuals in shoals than singletons. However, we also found that attacks directed at shoals were less likely to succeed. This suggests that the optimal strategy for guppies co-existing with this predator is to reduce shoaling to reduce the probability of being attacked, and to form shoals when an attack is initiated. We then asked if guppies modified their shoaling behavior in response to visual and olfactory cues from this predator during development. We found changes in guppy behavior in response to the treatment: guppies increased shoaling behavior when there was heightened risk of predation.

    

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