Publications by authors named "Reymond G"

Accurate tracking and analysis of animal behavior is crucial for modern systems neuroscience. However, following freely moving animals in naturalistic, three-dimensional (3D) or nocturnal environments remains a major challenge. Here, we present EthoLoop, a framework for studying the neuroethology of freely roaming animals.

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  • Primates, particularly long-tailed macaques, exhibit complex social behaviors influenced by past interactions, demonstrating the potential for reciprocity in their relationships.
  • Controlled experiments show these monkeys can reciprocate in a social decision-making task, but mainly in scenarios involving negative outcomes (like receiving an air puff).
  • The monkeys' ability to reciprocate depends on witnessing their partner's decisions, indicating that their social interactions are driven by a mix of revenge for negative experiences and gratitude for positive ones.
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  • MDMA was tested for its effects on social behaviors in young male long-tailed macaques, marking the first study of its kind on non-human primates.
  • Three doses of MDMA (1.0, 1.5, and 2.0 mg/kg) were administered, revealing significant effects on behaviors like social grooming, foraging, and locomotion.
  • Specifically, a 1.5 mg/kg dose increased social grooming, while doses of 1.5 and 2.0 mg/kg decreased foraging, and a 2.0 mg/kg dose increased locomotion, demonstrating MDMA's potential impact on primate social dynamics.
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  • Many primates, particularly long-tailed macaques, engage in solitary object play, which is important for their behavior and social dynamics.
  • A study introduced a unique toy to a group of these macaques, revealing that access to the toy created competition reflecting their social hierarchy.
  • The findings suggest that object play and social interactions are motivated by different factors, as competition for the toy reduced social contact among the monkeys, similar to how humans perceive competitors as threats.
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To date, assessing the solitary and social behaviors of laboratory primates' colonies relies on time-consuming manual scoring methods. Here, we describe a real-time multi-camera 3D tracking system developed to measure the behavior of socially-housed primates. Their positions are identified using non-invasive color markers such as plastic collars, thus allowing to also track colored objects and to measure their usage.

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When a slowly moving pattern is presented on a monitor which itself is moved, the pattern appears to freeze on the screen (Mesland and Wertheim in Vis Res 36(20):3325-3328, 1996) even if we move our head with the monitor, as with a head mounted display (Pavard and Berthoz in Perception 6:529-540, 1977). We present a simple model of these phenomena, which states that the perceived relative velocity between two stimuli (the pattern and the moving monitor) is proportional to the difference between the perceived velocities of these stimuli in space, minus a noise factor. The latter reflects the intrinsic noise in the neural signals that encode retinal image velocities.

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We have realized a very small optical dipole trap that is designed to store and manipulate individual atoms. Due to the very small dipole-trap volume, a 'collisional blockade' mechanism locks the average number of trapped atoms at a value of 0.5 over a large range of loading rates.

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This article describes a computational model for the sensory perception of self-motion, considered as a compromise between sensory information and physical coherence constraints. This compromise is realized by a dynamic optimization process minimizing a set of cost functions. Measure constraints are expressed as quadratic errors between motion estimates and corresponding sensory signals, using internal models of sensor transfer functions.

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We analyze the operating regimes of a very small optical dipole trap, loaded from a magneto-optical trap, as a function of the atom loading rate, i.e., the number of atoms per second entering the dipole trap.

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Experimental studies show that automobile drivers adjust their speed in curves so that maximum vehicle lateral accelerations decrease at high speeds. This pattern of lateral accelerations is described by a new driver model, assuming drivers control a variable safety margin of perceived lateral acceleration according to their anticipated steering deviations. Compared with a minimum time-to-lane-crossing (H.

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The ability to manipulate individual atoms, ions or photons allows controlled engineering of the quantum state of small sets of trapped particles; this is necessary to encode and process information at the quantum level. Recent achievements in this direction have used either trapped ions or trapped photons in cavity quantum-electrodynamical systems. A third possibility that has been studied theoretically is to use trapped neutral atoms.

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