Sensory Processes at the Neuronal and Behavioral Levels is a collection of papers dealing with problems of functional organization of the visual and auditory systems. One paper points out that neurophysiological and psychophysiological research in vision can be combined. The paper compares the cat's contrast stimulation by Hermann's grid that elicits neuronal responses of cells with concentric and simple fields as being similar to the subjective vision in man. Another paper addresses the sources of information in the perception of visual spatial relations. For example, eye movements as the source of information about visual spatial relations are refuted. The visual system already estimates accurately the spatial properties of an object before the onset of eye movements. Another paper discusses certain concepts about the mechanisms of the auditory system. One paper presents the results of an experiment involving some adult cats. They were lightly anesthetized and their responses were recorded when the inferior colliculus, or the left and right auditory cortex were stimulated electrically. Another paper analyzes the mechanism used by insect in recognizing species-specific songs. This book is suitable for neurophysiologists, neurochemists, and researchers dealing with physiological acoustics and the psychophysics of the visual system.