The Experts below are selected from a list of 204 Experts worldwide ranked by ideXlab platform

Jack M. Loomis - One of the best experts on this subject based on the ideXlab platform.

  • Counterexample to the hypothesis of functional similarity between tactile and visual Pattern Perception
    Attention Perception & Psychophysics, 1993
    Co-Authors: Jack M. Loomis
    Abstract:

    In earlier work, the author has demonstrated that tactile Pattern Perception and visual Pattern Perception exhibit many parallels when the effective spatial resolution of vision is reduced to that of touch, thus supporting the hypothesis that the two Pattern senses are functionally similar when matched in spatial bandwidth. The present experiments demonstrate a clear counter-example to this hypothesis of functional similarity. Specifically, it was found that the lateral masking effect of a surround on tactile character recognition increases when the surround changes in composition from solid lines to dots, whereas for vision, recognition performance goes in the opposite direction. This finding necessitates some modification of the model of character recognition proposed by the author (Loornis, 1990) as it applies to the sensing of raised tactile Patterns. One possible modification would be to incorporate, as the initial stage of Pattern transformation, the continuum mechanics model for the skin that was developed by Phillips and Johnson (1981b).

Timothy D Griffiths - One of the best experts on this subject based on the ideXlab platform.

  • Training improves acoustic Pattern Perception.
    Current biology : CB, 2004
    Co-Authors: Jessica M. Foxton, Andrew Brown, Simon Chambers, Timothy D Griffiths
    Abstract:

    Pitch changes that occur in speech and melodies can be described in terms of contour Patterns of rises and falls in pitch and the actual pitches at each point in time. This study investigates whether training can improve the Perception of these different features. One group of ten adults trained on a pitch-contour discrimination task, a second group trained on an actual-pitch discrimination task, and a third group trained on a contour comparison task between pitch sequences and their visual analogs. A fourth group did not undergo training. It was found that training on pitch sequence comparison tasks gave rise to improvements in pitch-contour Perception. This occurred irrespective of whether the training task required the discrimination of contour Patterns or the actual pitch details. In contrast, none of the training tasks were found to improve the Perception of the actual pitches in a sequence. The results support psychological models of pitch processing where contour processing is an initial step before actual pitch details are analyzed [1, 2]. Further studies are required to determine whether pitch-contour training is effective in improving speech and melody Perception.

  • Reading skills are related to global, but not local, acoustic Pattern Perception
    Nature Neuroscience, 2003
    Co-Authors: Jessica M. Foxton, Hal Brace, Fiona Mcintyre, Joel B. Talcott, Caroline Witton, Timothy D Griffiths
    Abstract:

    Although reading ability has been related to the processing of simple pitch features such as isolated transitions or continuous modulation spoken language also contains complex Patterns of pitch changes that are important for establishing stress location and for segmenting the speech stream. These aspects of spoken language processing depend critically on pitch Pattern (global structure) rather than on absolute pitch values (local structure). Here we show that the detection of global structure, and not local structure, is predictive of performance on measures of phonological skill and reading ability, which supports a critical importance of pitch contour processing in the acquisition of literacy.

Yanxi Liu - One of the best experts on this subject based on the ideXlab platform.

  • a computational model for periodic Pattern Perception based on frieze and wallpaper groups
    IEEE Transactions on Pattern Analysis and Machine Intelligence, 2004
    Co-Authors: Yanxi Liu, Robert T. Collins, Yanghai Tsin
    Abstract:

    We present a computational model for periodic Pattern Perception based on the mathematical theory of crystallographic groups. In each N-dimensional Euclidean space, a finite number of symmetry groups can characterize the structures of an infinite variety of periodic Patterns. In 2D space, there are seven frieze groups describing monochrome Patterns that repeat along one direction and 17 wallpaper groups for Patterns that repeat along two linearly independent directions to tile the plane. We develop a set of computer algorithms that "understand" a given periodic Pattern by automatically finding its underlying lattice, identifying its symmetry group, and extracting its representative motifs. We also extend this computational model for near-periodic Patterns using geometric AIC. Applications of such a computational model include Pattern indexing, texture synthesis, image compression, and gait analysis.

  • a computational model for repeated Pattern Perception using frieze and wallpaper groups
    Computer Vision and Pattern Recognition, 2000
    Co-Authors: Yanxi Liu, Robert T. Collins
    Abstract:

    Humans have an innate ability to perceive symmetry, but it is not obvious how to automate this powerful insight. In this paper the mathematical theory of frieze and wallpaper groups is used to extract visually meaningful building blocks (motifs) from a repeated Pattern. A novel peak detection algorithm based on "regions of dominance" is used to automatically detect the underlying translational lattice of a repeated Pattern. Following automatic classification of the Pattern's symmetry group, knowledge of the interplay between rotation, reflection, glide-reflection and translation in that group leads to a small set of candidate motifs that exhibit local symmetry consistent with the global symmetry of the entire Pattern. Although other work has addressed detection of the translational lattice of a repeated Pattern, ours is the first to seek a principled method for determining a representative motif. Experiments show that the-resulting Pattern motifs conform well with human Perception.

  • CVPR - A computational model for repeated Pattern Perception using frieze and wallpaper groups
    Proceedings IEEE Conference on Computer Vision and Pattern Recognition. CVPR 2000 (Cat. No.PR00662), 1
    Co-Authors: Yanxi Liu, Robert T. Collins
    Abstract:

    Humans have an innate ability to perceive symmetry, but it is not obvious how to automate this powerful insight. In this paper the mathematical theory of frieze and wallpaper groups is used to extract visually meaningful building blocks (motifs) from a repeated Pattern. A novel peak detection algorithm based on "regions of dominance" is used to automatically detect the underlying translational lattice of a repeated Pattern. Following automatic classification of the Pattern's symmetry group, knowledge of the interplay between rotation, reflection, glide-reflection and translation in that group leads to a small set of candidate motifs that exhibit local symmetry consistent with the global symmetry of the entire Pattern. Although other work has addressed detection of the translational lattice of a repeated Pattern, ours is the first to seek a principled method for determining a representative motif. Experiments show that the-resulting Pattern motifs conform well with human Perception.

Robert T. Collins - One of the best experts on this subject based on the ideXlab platform.

  • a computational model for periodic Pattern Perception based on frieze and wallpaper groups
    IEEE Transactions on Pattern Analysis and Machine Intelligence, 2004
    Co-Authors: Yanxi Liu, Robert T. Collins, Yanghai Tsin
    Abstract:

    We present a computational model for periodic Pattern Perception based on the mathematical theory of crystallographic groups. In each N-dimensional Euclidean space, a finite number of symmetry groups can characterize the structures of an infinite variety of periodic Patterns. In 2D space, there are seven frieze groups describing monochrome Patterns that repeat along one direction and 17 wallpaper groups for Patterns that repeat along two linearly independent directions to tile the plane. We develop a set of computer algorithms that "understand" a given periodic Pattern by automatically finding its underlying lattice, identifying its symmetry group, and extracting its representative motifs. We also extend this computational model for near-periodic Patterns using geometric AIC. Applications of such a computational model include Pattern indexing, texture synthesis, image compression, and gait analysis.

  • a computational model for repeated Pattern Perception using frieze and wallpaper groups
    Computer Vision and Pattern Recognition, 2000
    Co-Authors: Yanxi Liu, Robert T. Collins
    Abstract:

    Humans have an innate ability to perceive symmetry, but it is not obvious how to automate this powerful insight. In this paper the mathematical theory of frieze and wallpaper groups is used to extract visually meaningful building blocks (motifs) from a repeated Pattern. A novel peak detection algorithm based on "regions of dominance" is used to automatically detect the underlying translational lattice of a repeated Pattern. Following automatic classification of the Pattern's symmetry group, knowledge of the interplay between rotation, reflection, glide-reflection and translation in that group leads to a small set of candidate motifs that exhibit local symmetry consistent with the global symmetry of the entire Pattern. Although other work has addressed detection of the translational lattice of a repeated Pattern, ours is the first to seek a principled method for determining a representative motif. Experiments show that the-resulting Pattern motifs conform well with human Perception.

  • CVPR - A computational model for repeated Pattern Perception using frieze and wallpaper groups
    Proceedings IEEE Conference on Computer Vision and Pattern Recognition. CVPR 2000 (Cat. No.PR00662), 1
    Co-Authors: Yanxi Liu, Robert T. Collins
    Abstract:

    Humans have an innate ability to perceive symmetry, but it is not obvious how to automate this powerful insight. In this paper the mathematical theory of frieze and wallpaper groups is used to extract visually meaningful building blocks (motifs) from a repeated Pattern. A novel peak detection algorithm based on "regions of dominance" is used to automatically detect the underlying translational lattice of a repeated Pattern. Following automatic classification of the Pattern's symmetry group, knowledge of the interplay between rotation, reflection, glide-reflection and translation in that group leads to a small set of candidate motifs that exhibit local symmetry consistent with the global symmetry of the entire Pattern. Although other work has addressed detection of the translational lattice of a repeated Pattern, ours is the first to seek a principled method for determining a representative motif. Experiments show that the-resulting Pattern motifs conform well with human Perception.

Xiuying Qian - One of the best experts on this subject based on the ideXlab platform.

  • tactile Pattern Perception by two fingers temporal interference and response competition
    Attention Perception & Psychophysics, 1997
    Co-Authors: James C. Craig, Xiuying Qian
    Abstract:

    The identification of a spatial Pattern (target) presented to one fingerpad may be interfered with by the presentation of a second Pattern (nontarget) to either the same fingerpad or a second fingerpad. A portion of the interference appears to be due to masking and a portion to response competition. In the present study, vibrotactile spatial Patterns were designed to extend over two fingerpads. Target and nontarget Patterns were presented to the same two fingerpads with a temporal separation between the two Patterns. The function relating target identification to the temporal separation between the target and nontarget was very similar to the functions obtained with one-finger Patterns in temporal masking studies. Subsequent measurements showed that a substantial portion of the interference resulted from response competition. Pattern categorization was better when Patterns were presented to two fingers on opposite hands than to two fingers on the same hand; however, there was more interference for Patterns presented bilaterally than for Patterns presented ipsilaterally. The results supported the conclusion that similar processes are involved in the Perception of sequences of spatial Patterns whether the Patterns are presented to one or to two fingers.