title: Escape response of the crab Neohelice to computer generated looming and translational visual danger stimuli.
abstract: Historically, arthropod behavior has been considered to be a collection of simple, automaton-like routines commanded by domain-specific brain modules working independently. Nowadays, it is evident that the extensive behavioral repertoire of these animals and its flexibility necessarily imply far more complex abilities than originally assumed. For example, even what was thought to be a straightforward behavior of crabs, the escape response to visual danger stimuli, proved to involve a number of sequential stages, each of which implying decisions made on the bases of stimulus and contextual information. Inspired in previous observations on how the stimulus trajectory can affect the escape response of crabs in the field, we investigated the escape response to images of objects approaching directly toward the crab (looming stimuli: LS) or moving parallel to it (translational stimuli: TS) in the laboratory. Computer simulations of moving objects were effective to elicit escapes. LS evoked escapes with higher probability and intensity (speed and distance of escape) than TS, but responses started later. In addition to the escape run, TS also evoked a defensive response of the animal with its claws. Repeated presentations of TS or LS were both capable of inducing habituation. Results are discussed in connection with the possibilities offered by crabs to investigate the neural bases of behaviors occurring in the natural environment.
authors.affiliation: Laboratorio de Neurobiología de la Memoria. Depto. Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IFIBYNE-CONICET, Buenos Aires, Argentina.
authors.forename: Florencia
authors.initials: F
authors.lastname: Scarano
authors.affiliation: Laboratorio de Neurobiología de la Memoria. Depto. Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IFIBYNE-CONICET, Buenos Aires, Argentina. Electronic address: tomsic@fbmc.fcen.uba.ar.
authors.forename: Daniel
authors.initials: D
authors.lastname: Tomsic
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D003386:Brachyura / Q000502:physiology*; D003198:Computer Simulation; D004924:Escape Reaction / Q000502:physiology*; D005121:Extremities; D008297:Male; D009039:Motion Perception / Q000502:physiology; D009043:Motor Activity / Q000502:physiology; D010775:Photic Stimulation; D011235:Predatory Behavior; D014796:Visual Perception / Q000502:physiology
keywords: Antipredator response; Defensive; Habituation; Stimulus trajectory; Visually guided behaviors