Khan, Jeremy I (1980) Visual comparison of patterns: the significance of pattern transformation and pattern arrangement in the visual field. Doctoral thesis, Keele University.

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Abstract

The two main types of scheme for the internal representation and internal processing of visual stimuli involve either a 'pointlllistic' internal representation to which various internal compensatory transformations can be applied, or a structured, internal representation that consists of elements representing the local features in the stimulus and elements representing the spatial relations between these local features. The two types of scheme naturally predict different effects of stimulus arrangement on performance for the 'same- different' comparison of patterns. The results of a number of experiments designed to examine these effects show that:
(i) judgements of the 'sameness' of pairs of identical patterns are most affected by the distance between the two patterns:
(ii) judgements of the 'sameness' of pairs of patterns where one has been reflected or rotated through 180° are most affected by the symmetry of the pattern positions with respect to the point of fixation.
Since neither of the two types of scheme described above can adequately explain these results, a new scheme is proposed. In this scheme, the internal representation consists of elements representing the local features in the stimulus, elements representing the spatial relations between the local features, and additional elements representing the position of the stimulus with respect to the point of fixation. It is proposed that two types of operation can be performed on this internal representation: a global relabelling of element types, and a progressive continuous modification of individual elements.
The proposed scheme is shown to be adequate to explain the effects of pattern arrangement described above, and various predictions are made from the scheme, concerning the 'same-different' comparison of patterns related by reflections and by various other transformations. These predictions are verified in a number of further experiments which confirm all the major components of the proposed scheme.

Item Type: Thesis (Doctoral)
Subjects: R Medicine > RC Internal medicine > RC0321 Neuroscience. Biological psychiatry. Neuropsychiatry
Divisions: Faculty of Natural Sciences > School of Life Sciences
Contributors: Foster, David (Thesis advisor)
Depositing User: Lisa Bailey
Date Deposited: 03 Oct 2019 09:32
Last Modified: 03 Oct 2019 09:32
URI: http://eprints.keele.ac.uk/id/eprint/6955

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