title: Contingency learning and causal detection in Hermissenda: I. Behavior.
abstract: The addition of extra light-alone or rotation-alone presentations to sequences of light-rotation pairings reduced the associative suppression of phototaxic behavior for the nudibranch Hermissenda. Training-induced changes in Type B photoreceptor light responses were found to parallel the training-induced behavioral changes in the intact animal. The decremental effects of the degraded contingency treatments upon neural and behavioral changes normally occasioned by light-rotation pairings reflected two processes. One factor was the increased stimulation frequency entailed by degraded contingency training. The second factor reflected the specifically unpaired character of the added light-alone or rotation-alone presentations, independent of frequency changes. The attenuation of phototaxic suppression was not because of a general habituation process or adaptation to the effects of either visual or vestibular stimulation. Instead, attenuation seemed to reflect a local interference effect of interspersed unpaired stimuli. The present experiments demonstrate a sensitivity to stimulus contingencies for Hermissenda similar to that of many vertebrates and indicate that contiguity and contingency relations are both encoded and stored in the Type B photoreceptors. The results indicate that similar neurophysiological mechanisms are involved.
mesh_terms: D000818:Animals; D001245:Association Learning / Q000502:physiology; D003214:Conditioning, Classical / Q000502:physiology; D007858:Learning / Q000502:physiology; D008027:Light; D008570:Memory, Short-Term / Q000502:physiology; D008974:Mollusca / Q000502:physiology; D009949:Orientation / Q000502:physiology; D010153:Paired-Associate Learning / Q000502:physiology; D010786:Photoreceptor Cells / Q000502:physiology; D014796:Visual Perception