Werner Von Seelen

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In this report we present the rst results of a very eecient scheme for vehicle detection in traac scenes. It is based on the detection of the shadows underneath the vehicles. The use of shadow as sign pattern was rst reported in 5]. Herein a histogram evaluation of the paved road sustains the speciication of a threshold value for the shaded areas. This(More)
We measured reflectance changes by means of optical imaging of intrinsic signals to study the topography of the paw representations in rat somatosensory cortex. Following circumscribed tactile stimulation of single digits or pads, we found large and partially overlapping areas of reflectance changes (delta R). The diameters of their focal zones defined at(More)
If one eye sees a bright field on a dark surround while a homogeneous background is presented to the other eye, then a distinct dark zone appears at the outer borders of the field. If the surround is coloured, then the zone is of corresponding hue. The effect disappears if the edge of the field can be fused with a bar of appropriate contrast. The influence(More)
We measured reflectance changes by means of optical imaging of intrinsic signals to study the effects of acute electrical cochlear stimulation on the topography of the cat auditory cortex. After single-pulse electrical stimulation at selected sites of a multichannel implant device, we found topographically restricted response areas representing mainly the(More)
The contribution of the lateral suprasylvian cortex to pattern recognition was studied by behavioural detection experiments in combination with bilateral lesions of different parts of the lateral suprasylvian areas (LSA) and area 7 in seven cats. In a two-alternatives forced choice task the cats had to discriminate simple outline patterns which were(More)
The coupling complexity of cortical areas makes it very difficult to analyse them experimentally. Studies of model systems provide the possibility of adapting the analysis to the available data base and elaborating the fundamental properties that depend on the structure of the system. We propose a model system of variable complexity that is spatially(More)
Behavioural research, neurophysiological experiments and computer simulations are used in an attempt to analyze pattern recognition in the cat's visual system. The methods were chosen in such a way that the measurable performance data resulting from behavioural and neurophysiological experiments can be combined simply. It is shown that, with minor(More)
Superimposing additively a two-dimensional noise process to deterministic input signals (bars) the neurons of area 17 show a class-specific reaction for the task of signal extraction. Moving both parts of the signals simultaneously and varying the signal to noise ratio (S/N) the simple cells achieve the same performance as resulted from the psychophysical(More)
Proceeding from previous studies on cells in area 18, neurophysiological experiments were carried out using combination of deterministic and statistical stimuli. The evaluation of the results on the space, time and amplitude characteristic of the cells show that for nearly all cells in this area, pattern distortion and shift due to motion are eliminated by(More)