Neural correlates of key stimulus and releasing mechanism: a case study and two concepts

Major themes in neuroethology concern the specificity of key stimuli, neurones tuned to such stimuli, and the release of corresponding behaviour. Neurobiological data from the analysis of visuomotor functions of prey-catching and avoiding in amphibians support the view that retinal outflow in different combinations is pooled for further computation in interacting processing streams, rather than segregated into distinct retinal channels. The keys by which the visual system gets access to perceptual-motor categories are shown to derive from specific computational strategies that evaluate significant configurational features of objects. Rapid behavioural responses are assured by visuomotor pathways which, monitoring different aspects of visual objects, collectively select appropriate motor patterns. Responses can be adapted to varying environmental and internal conditions via modulating and modifying loops. This requires parallel distributed processing and integration at various levels in a macro-network.