Learn More
The effect of feature displacement within two well-known faces (Terry Wogan and Cyril Smith) was examined. Image processing equipment was used to produce stimuli in which the features of an original facial image were displaced to form a number of modified images. This technique was first reported by Haig, in a recognition study in which the effect of(More)
Human beings possess a remarkable ability to recognise familiar faces quickly and without apparent effort. In spite of this facility, the mechanisms of visual recognition remain tantalizingly obscure. An experiment is reported in which image processing equipment was used to displace slightly the features of a set of original facial images to form groups of(More)
The aim of this paper is to report an extension to the computationally efficient Self Similar Stack model (Burton et al. Biol., Cybernet. 53, 397-403, 1986) to include the effects of local gain control in the retina. The method employed to do this has been to fit a family of difference-of-Gaussian functions to the human contrast sensitivity function curves(More)
It can be argued that the process of recognizing faces progresses in two stages: first, the realisation that a perceived image contains patterns that may most reasonably be interpreted as forming a discrete face; second, correct and positive identification by noting the particular features that differentiate one face from all others. A novel technique which(More)
A new visual illusion is reported, in which a sine-wave grating appears to tilt when doubly sheared perpendicularly to the grating lines. It is shown that the illusory percept is related to the Münsterberg and Café Wall illusions. The probable mechanism at the root of all such illusions is postulated by reference to the neuroarchitecture of the retina and(More)
It is established that the resolving power of the eye accords with that predicted by diffraction theory. Campbell and Green (J. Physiol. 181, 576-593, 1965) and Campbell and Gubisch (J. Physiol. 186, 558-578, 1966) demonstrated that the eye exhibits nearly diffraction-limited performance at 2 mm pupil diameter, resolving up to approximately 60 cyc deg-1.(More)
The application of theoretical neural networks to preprocessed images was investigated with the aim of developing a computational recognition system. The neural networks were trained by means of a back-propagation algorithm, to respond selectively to computer-generated bars and edges. The receptive fields of the trained networks were then mapped, in terms(More)
  • 1