A conventional understanding of perception assigns sensory organs the role of capturing the environment. Better sensors result in more accurate encoding of stimuli, allowing for cognitive processing downstream. Here we show that plasticity in sensory neurons mediates a behavioral switch in C. elegans between attraction to NaCl in naïve animals and avoidance of NaCl in preconditioned animals, called gustatory plasticity. Ca2+ imaging in ASE and ASH NaCl sensing neurons reveals multiple cell-autonomous and distributed circuit adaptation mechanisms. A computational model quantitatively accounts for observed behaviors and reveals roles for sensory neurons in the control and modulation of motor behaviors, decision making and navigational strategy. Sensory adaptation dynamically alters the encoding of the environment. Rather than encoding the stimulus directly, therefore, we propose that these C. elegans sensors dynamically encode a context-dependent value of the stimulus. Our results demonstrate how adaptive sensory computation can directly control an animal’s behavioral state.

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Robust system design is becoming increas ingly important, because of the ongoing miniaturization of integrated circuits, the increasing effects of aging mecha nisms, and the effects of parasitic elements, both intrin sic and external. For safety reasons, particular emphasis is placed on robust system design in the automotive and aerospace sectors. Until now, the term robustness has been applied very intuitively and there has been no proper way to actually measure robustness. However, the complexity of contemporary systems makes it difficult to fulfill tight specifications. For this reason, robustness must be inte grated into a partially automated design flow. In this pa per, a new approach to robustness modeling is presented, in addition to new ways to quantify or assess the robustness of a design. To demonstrate the flexibility of the proposed approach, it is adapted and applied to several different sce narios. These include the robustness evaluation of digital circuits under aging effects, such as NBTI; the robustness modeling of analog and mixed signal circuits using affine arithmetic; and the robustness study of software algorithms on a high system level.

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A conventional understanding of perception assigns sensory organs the role of capturing the environment. Better sensors result in more accurate encoding of stimuli, allowing for cognitive processing downstream. Here we show that plasticity in sensory neurons mediates a behavioral switch in C. elegans between attraction to NaCl in naive animals and avoidance of NaCl in preconditioned animals, called gustatory plasticity. Ca2+ imaging in ASE and ASH NaCl sensing neurons reveals multiple cell-autonomous and distributed circuit adaptation mechanisms. A computational model quantitatively accounts for observed behaviors and reveals roles for sensory neurons in the control and modulation of motor behaviors, decision making and navigational strategy. Sensory adaptation dynamically alters the encoding of the environment. Rather than encoding the stimulus directly, therefore, we propose that these C. elegans sensors dynamically encode a context-dependent value of the stimulus. Our results demonstrate how adaptive sensory computation can directly control an animal′s behavioral state.