Erich Harth

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Axonal fiber distributions of pyramidal cells in the visual cortex of the albino rat have been investigated using the rapid Golgi method and modern data collecting techniques. Three dimensional coordinate information was extracted from Golgi-impregnated axonal networks using a computer-assisted video digitizer. Computer programs used this data to generate(More)
The mammalian visual system has a hierarchic structure with extensive reciprocal connections. A model is proposed in which the feedback pathways serve to modify afferent sensory stimuli in ways that enhance and complete sensory input patterns, suppress irrelevant features, and generate quasi-sensory patterns when afferent stimulation is weak or absent. Such(More)
Subjective consciousness suggests a unity of the sensing and perceiving self that is difficult to reconcile with the multiplicity of sensory analyzers and the absence of a convergence zone in the brain. This has led--on the one hand--to the dead-end assumption of a unifying sentient homunculus and--on the other--to a denial of conscious unity. The sketchpad(More)
The determination of trigger features of single neurons in afferent pathways has been one of the central problems in sensory physiology. A novel method, called Alopex, has been developed, in which response feedback is used to construct visual patterns that optimize the responses. Data are presented which show the emergence of trigger features of cells(More)
We have proposed a theory in which pathways ascending from the brainstem reticular formation control sensory centers in the dorsal thalamus and neocortex. We assumed that the sensory messages received at a given level are transformed by a stochastic process, called Alopex, in a way which maximizes responses in central feature analyzers. Perception is seen(More)
A computer simulation model of the neural circuity underlying orientation sensitivity in cortical neurons is examined. The model consists of a network of 3000 neurons divided into two functionally distinct cell types: excitatory (E-cells) and inhibitory (I-cells). We demonstrate that both orientation sensitivity and shape selectivity can be accounted for by(More)