Downloads & Free Reading Options - Results

The publications describe progress in two related areas of visual information processing: motion processing and visual attention. The full equivalence between Reichart motion detection and Fourier motion analysis (first-order motion processing) was proved formally. A new experimental paradigm was developed to test the model of nonFourier (2nd-order) motion processing. This model, which accounts for the perception of motion-from-texture, consists of a stage of linear spatio-temporal filtering followed by fullwave rectification and then by standard (Reichart) motion analysis. It was demonstrated that human 2nd-order motion is, for practical purposes, one-dimensional (i.e., a single channel system). The spatial filter that this channel utilizes was measured and found to be lowpass. Work on attentional processes in visual task using rapid sequences of superimposed patterns showed that highly trained subjects were unable to use gross physical differences to filter out unattended items at an early stage of perceptual processing. On the contrary, the results are explained by postulating that attended and unattended elements of the input are tagged as such at an early-stage, and are then discriminated later on the of this tag. (Author)