Showing papers by "Kevin Gurney published in 1995"
TL;DR: The findings support the proposal that rotation discrimination (at short ISIs) is achieved by a template mechanism combining signals from different directional detectors, rather than by cognitive comparison of the outputs of the directional mechanisms themselves.
Abstract: Thresholds were measured for discrimination of direction of a step angular rotation of gratings. The addition of simultaneous phase displacements (translation) had little effect on rotation thresholds for gratings over a considerable range; discrimination of rotation is unaffected by random directional translations an order of magnitude larger. Angular rotation discrimination thresholds increased with interstimulus interval (ISI). Thus discrimination is based at short ISIs (180 ms or less) on a percept of rotary motion, but at ISIs of several seconds by a spatial strategy (comparing static component orientations) relying on visual memory. Data points for the short-ISI region fell below the best-fitting straight line, and the slope of the short-ISI region of the curve was steeper than that of the long-ISI region. However, when either compound or simple gratings with uncorrelated spatial frequencies were used in the two stimulus frames, there was no evidence for a separate function at short ISIs. Orientatio...
6 citations
02 Jan 1995
TL;DR: The use of networks of logical processing elements to effect pattern matching and pattern recognition has been the subject of much research since the birth of digital microelectronic systems and exploited the potential of RAM technology to develop hardware realisations of the N-Tuple method.
Abstract: The use of networks of logical processing elements to effect pattern matching and pattern recognition has been the subject of much research since the birth of digital microelectronic systems. In 1959, Bledsoe and Browning (59) proposed the N-Tuple method of pattern recognition. The technique offered a relatively low-cost approximation to Bayesian classification and formed the basis for many pattern recognition studies in the sixties (see for instance, Steck 62, Ullmann 69). Later, Aleksander and colleagues exploited the potential of RAM technology to develop hardware realisations of the the N-Tuple method which allowed real time learning and classification (the WIS ARD system, Aleksander 84).
1 citations
01 Jan 1995
TL;DR: In this work, the author had the privilege of working with Hisako Ikeda between 1970 and 1975, and carried out extensive single cell recording studies in the retina, LGN and visual cortex of cats, which conducted some of the earliest studies on animal models of amblyopia.
Abstract: One of the authors (MW) had the privilege of working with Hisako Ikeda between 1970 and 1975, and carried out extensive single cell recording studies in the retina, LGN and visual cortex of cats. Ikeda and Wright (1976) also conducted some of the earliest studies on animal models of amblyopia, in which they looked at the effects of surgically induced squint in kittens on the responsiveness of single cells in the LGN. This work was interpreted within a framework of parallel processing streams in the visual pathways. All these issues are very much still current concerns of the Vision Research community. One of these topics, parallel processing and spatiotemporal tuning of cortical neurons is the subject of current research at Brunel University. In this work, we try to develop models and explanations of human vision, for instance, human motion perception, which are firmly rooted in physiology, and make use of fundamental neurophysiological findings in deriving explanations of human visual performance.