Bulletin of the American Physical Society
APS March Meeting 2022
Volume 67, Number 3
Monday–Friday, March 14–18, 2022; Chicago
Session N03: Animal Behavior IFocus Recordings Available
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Sponsoring Units: DBIO Chair: Joshua Shaevitz, Princeton University Room: McCormick Place W-176A |
Wednesday, March 16, 2022 11:30AM - 12:06PM |
N03.00001: Inferring long timescale dynamics in animal behavior Invited Speaker: Gordon J Berman Animal behavior consists of an intricate hierarchy of dynamics, from brief muscle twitches to stereotyped behaviors to longer-lived states like hunger, aggression, and parenting. How does an animal bridge these timescales to create complex sequences of actions? The approach that most researchers take when studying sequences of behaviors tends to be probabilistic, observing how discrete states transition in a largely memoryless fashion. In this talk, we take a different approach, fitting dynamical models to long behavioral sequences from fruit flies and rodents. We show that these models replicate many summary statistics of the underlying behavioral sequence data and that their fixed points have a geometry that mirrors the geometry of the animals' behavioral repertoires. In addition, we show that the long timescales generated by this model are best explained by a hierarchy of interacting dynamical subsystems that is comparable to the hierarchical structure of behavior. These results suggest a new framework for uncovering the hidden states that modulate the behaviors that an animal performs - predicting how physiology may be linked to behavior and how behaviors may evolve. |
Wednesday, March 16, 2022 12:06PM - 12:18PM |
N03.00002: Sensorimotor transformations underlying spider web-making Abel Corver, Andrew Gordus The geometric complexity and stereotypy of spider webs have long generated interest in their algorithmic origin. Web-making is especially amenable to comprehensive modeling because both the input and output of this behavior consist of the web itself, which can be specified completely in terms of its geometry. However, quantitative analyses have been sparse due to the difficulty of recording web-making in real-time. In recent computational work, we demonstrated that the stages of this behavior are generated by distinct and stereotyped motor sequences, but the sensorimotor and internal state mechanisms that generate these observed sequences remain unknown. Here, we present an assay and algorithms for real-time tracking of limb movements and web structure produced by the orb-weaver Uloborus diversus. We capture tactile interactions between spider and web and identify sensory cues triggering motor actions. Due to the conjugate relationship between leg movements and web geometry, these sensorimotor rules can be reanalyzed in terms of the effect their accompanying geometrical transformations have on web fitness. With parallel efforts in our group to establish calcium imaging in this small spider, it may offer a tractable model for the study of complex and likely cognitive behaviors. |
Wednesday, March 16, 2022 12:18PM - 12:30PM |
N03.00003: Characterizing social impairments in rat models of ASD Ugne Klibaite, Jesse D Marshall, Timothy Dunn, Diego Aldarondo, Bence P Olveczky Social interaction is a core component of animal behavior, and the tracking and quantification of spontaneous social behavior presents several challenges in both computer vision and interpretation. We extend a recently developed technique for 3D kinematic tracking of single animals (DANNCE) to capture the 3D poses of freely interacting animals by tracking animal identity and refining keypoint labeling networks to maintain accuracy during touching and occlusion. Using this approach, we have acquired a rich dataset of interactions across pairings from autism spectrum disorder (ASD) knockout rats and their normal counterparts. We use a dynamical embedding approach to parse animal movement throughout solitary and social contexts to find behaviors or 'gestures' which are preferentially expressed in the social context, and timestamp periods of behavioral synchronization during interaction. We find that social exchanges differ between ASD and control animals, and preliminary analysis of these interactions in the Cntnap2 rat model suggests that epochs of synchronized behaviors are dominated by aggressive behaviors in ASD pairs and more canonical play-fighting behavior in wild type animals. |
Wednesday, March 16, 2022 12:30PM - 12:42PM |
N03.00004: Hierarchical timescales of free behavior Kanishk Jain, Tomaso Muzzu, Elena Menichini, Jakob Macke, Aman Saleem, Gordon J Berman Animal behavior is a multiscale process. At the smallest scale, it can be deconstructed as a series of stereotypic postural movements performed by the animal. However, behavior is driven by intricate internal and external processes occurring at multiple long-timescales. In order to understand these processes it then becomes imperative for us to represent behavior at multiple timescales. Here, we use a Recurrent Neural Network (RNN) based modeling approach to create representations of animal behavior at multiple timescales. Using markerless tracking, we measured the postural dynamics of freely behaving rats as they move throughout an enriched arena over 3-hour sessions. We then train a novel multi-layer and time-dilating RNN to predict these dynamics and use latent dynamics from each layer to create multiple two-dimensional density maps of behavioral states. We find that density maps from different layers exhibit dynamics at different timescales, allowing us to predict interactions between the internal neural and neuromodulatory states that regulate the rat's behavior across these scales. |
Wednesday, March 16, 2022 12:42PM - 12:54PM |
N03.00005: Long timescale structure in Drosophila behavior Scott W Wolf, Grace C McKenzie-Smith, Joshua W Shaevitz Animal behavior encompasses many timescales, from the shortest seconds-scale actions to daily circadian rhythms to aging across weeks, months, and years. Nearly all work on quantitative behavior has focused on behaviors on the short timescale, such as locomotion, grooming, and other sub-second and second-scale actions. An analysis of these data suggests there exists a large hierarchy of timescales; however, the limited duration of these experiments restricted the ability to investigate the full temporal structure (Berman, Bialek, & Shaevitz, 2016). To remedy this situation, we continuously recorded more than 50 individual Drosophila at a frame rate of 100Hz for weeks at a time, a substantial portion of their lifetime, in featureless arenas on sugar-agar media. The resulting recordings were analyzed using SLEAP (Pereira et al., 2020) to produce a full-body postural dataset with over 100 million pose instances per individual and a total of over 5 billion poses. We find rich features across timescales and present details of the dynamics of behavior across the lifespan of a fly. |
Wednesday, March 16, 2022 12:54PM - 1:06PM |
N03.00006: Why do octopuses camouflage when asleep? Leenoy Meshulam, Aditi Pophale, Kazumichi Shimizu, Sam Reiter Practice is a crucial component of mastering many movements. However, studies have shown that the rest periods in between practice sessions are equally important. During rest periods, and especially while asleep, human and animal brains undergo a process of 'offline practice' resulting in subsequent gains in behavioral performance. Nonetheless, it remains unclear how offline practice produces later improvements. To that end, we study octopus camouflage behavior. Octopuses' survival is dependent on quickly wielding their skin color and texture to display strikingly complex visual patterns. Here, we leverage our state-of-the-art high-resolution filming setup to report a near complete readout of the neural population responsible for generating the collective behavior of skin camouflage patterns. We utilize an entropy-based theoretical framework to quantitatively examine the collective nature of skin cell interactions over time. Beyond studying the potentially evolving relationship between patterns adopted during sleep and wake, we are working to show how manipulating the surroundings of the animal while awake affects the content of its practice during sleep. Together, these findings may help elucidate the complex nature of camouflage and the general phenomenon of 'offline practice'. |
Wednesday, March 16, 2022 1:06PM - 1:18PM |
N03.00007: Decoding locomotion from population neural activity in moving C. elegans Kelsey M Hallinen, Xinwei Yu, Ross Dempsey, Monika Scholz, Ashley Linder, Francesco Randi, Anuj K Sharma, Joshua W Shaevitz, Andrew M Leifer We investigated the neural representation of locomotion in the nematode C. elegans by recording population calcium activity during movement. We report that population activity more accurately decodes locomotion than any single neuron. Two largely distinct subpopulations are informative for decoding velocity and curvature, and different neurons’ activities contribute features relevant for different aspects of a behavior or different instances of a behavioral motif. We examined the subpopulations of our signals to investigate how the decoder utilizes information from the population. We inspected the neural weights assigned by the decoder and found some of our highest weighted neurons had activity traces that matched only specific features of our behavior. This indicates that the neural signals are distinct and not simply copies of the same signal. Finally, we present preliminary results from an investigation into the stereotypy of the neural code across animals. |
Wednesday, March 16, 2022 1:18PM - 1:30PM |
N03.00008: Monitoring odor landscape to study learned olfactory navigation in C. elegans Kevin S Chen, Rui Wu, Marc H Gershow, Andrew M Leifer Animals flexibly adjust behavior in response to environmental contexts and learned experiences. In C. elegans, associative learning with an olfactory cue generates chemotactic behavior towards the cue if it was paired with food. However, it is unknown if olfactory learning modulates sensory-motor processing for a specific navigation strategy, such as the bias in a biased random walk, or alternatively modulates other strategies adaptively. The biophysics with which worms sense airborne cues is also not well understood. Here we investigate butanone-odor associative learning using an odor chamber to precisely measure the odor concentration experienced by worms during odor-guided navigation. We control airborne cues to form a stationary chemical landscape that we measure with an array of digital gas sensors. As worms navigate in the environment, we track their trajectories and posture. We also developed a statistical model to capture different strategies previously characterized in worms, including biased random walk and gradual change in angle towards high concentration. We will discuss progress towards quantitatively characterizing learned odor-guided navigation with our apparatus and our proposed model. |
Wednesday, March 16, 2022 1:30PM - 1:42PM |
N03.00009: Hunting, scavenging, and kleptoparasitism: A fitness-maximising approach to predicting predator foraging strategy Ritwika Vallomparambath PanikkasserySu, Ajay Gopinathan, Justin D. Yeakel Mammalian carnivores' foraging strategies include hunting, scavenging, and kleptoparasitism (stealing). Despite the prevalence of literature on predator-prey systems, the factors that result in the deployment of these strategies and their effects on predator-prey systems (and ecological communities) are well understood. In this study, we use an energetics-based computational model to investigate how a focal predator's interactions with potential prey and other predators constrain the use of these strategies. Our results predict the dependence of predator foraging strategy on predator energetics as well the body sizes of the focal predator, prey, and the 'victim' of stealing/scavenging. In particular, our results predict the boundaries of predator foraging strategies exceptionally well. By employing dimensional reduction, we are able to describe the phase transition from a state where the focal predator relies predominantly on hunting to a state where the focal predator largely relies on scavenging and stealing, by a reverse sigmoidal function. We verify these results using data from a large number of field observations. Our model can be easily extended to predict the prevalence of different strategies in real predator-prey assemblages as well as the effect of predators foraging in groups on the deployment of different predator foraging strategies. |
Wednesday, March 16, 2022 1:42PM - 1:54PM |
N03.00010: Synchronized locomotion improves spatial accessibility in ant colonies and in oscillating active particles. Grant N Doering, Carmen L Lee, Kari Dalnoki-Veress Synchronization is a common and important collective phenomenon in many biological, physical, and even social systems. Ant colonies from the genus Leptothorax exhibit a form of synchronized behavior where workers inside colonies’ nests become active together in rhythmic cycles that have a period of approximately 20 minutes. However, it is not currently known if these synchronized rhythms of locomotion confer any functional benefit to the collective behavior of colonies. By using a combination of multiple image analysis techniques, we show that inactive ants act as immobile obstacles to moving ants and that, compared with asynchronous movement, synchronized activity reduces the likelihood that active ants will encounter clusters of inactive ants that impede access to regions of the nest. We model this system as a set of confined, oscillating active particles where the level of particle phase synchrony, average activity level, and particle density can be directly manipulated. Our model simulations reveal that synchronous activity provides the greatest improvements to spatial accessibility when particle density is high and when the duration particles spend inactive is long. |
Wednesday, March 16, 2022 1:54PM - 2:06PM |
N03.00011: Ant Cooperative Transport of Large Flexible Objects under Constraint Atanu Chatterjee, Hillel Aharoni, ofer feinerman Collective behavior in animal groups is affected by local interactions, external constraints, and an influx of information. In the context of cooperative transport of food items by a group of ants, it was shown that a trade-off exists between the well-coordinated pull of uninformed individuals and the directional information brought in by informed leaders. The ants were modeled as binary Ising spins, representing the two roles – pullers and lifters - they perform during the transport of solid objects. The assumption of solid objects implies perfect communication with zero delays. Here, we test the existing model by allowing a group of ants to collectively transport a large flexible food item constrained at one end and free at the other. Constraining the system causes it to behave not only like a non-linear pendulum but also like a soft beam that bends due to the ants' pulling forces. The bending rigidity of the system interferes with the macroscopic dynamics of the mechanically coupled ants, delaying their force-sensing capability, and thus breaking coordination while constraining communication. Therefore, we question the validity of the existing model for the case of a large soft object and study how ants still manage efficient transport despite limited communication. |
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